API 579-1/ASME FFS-1 Fitness-For-Service

Fitness-For-Service
Foreword
Special Notes
Contents
Part 1 – Introdution
	1.1 Introduction
		1.1.1 Construction Codes and Fitness-For-Service
		1.1.2 Fitness-For-Service Definition
	1.2 Scope
		1.2.1 Supplement to In-Service Inspection Codes
		1.2.2 Application Construction Codes
		1.2.3 Other Recognized Codes and Standards
		1.2.4 Remaining Life
		1.2.5 Assessment Methods for Flaw Types and Damage Conditions
		1.2.6 Special Cases
	1.3 Organization and Use
	1.4 Responsibilities
		1.4.1 Owner-User
		1.4.2 Inspector
		1.4.3 Engineer
			1.4.3.1 The Engineer is responsible to the Owner-User for most types of  assessments, documentation, and resulting recommendations.  The exception is that a Level 1 Assessment may be performed by an Inspector or other non-degreed specialist (see Part ...
			1.4.3.2 In the context of this Standard, the term Engineer applies to the combination of the following disciplines unless a specific discipline is cited directly.  A  assessment may require input from multiple engineering disciplines as described below.
		1.4.4 Plant Engineer
	1.5 Qualifications
		1.5.1 Education and Experience
		1.5.2 Owner-User
		1.5.3 Inspector
		1.5.4 Engineer
	1.6 Definition of Terms
	1.7 References
		1.7.1 Types
		1.7.2 Code, Standards and Recommended Practices
		1.7.3 Technical reports and Other Publications
	1.8 Tables
Annex 1A  – Glossary Of Terms And Definitions
	1A.1 Abs[a] or |a| – The definition of a mathematical function that indicates that the absolute value of the arguments, a, is to be computed.
	1A.2 AET – Acoustic Emission Testing.
	1A.3 Alteration – The definition depends on the equipment type and in-service code as shown below.
	1A.4 ASCC (Alkaline Stress Corrosion Cracking) – The cracking of a metal produced by the combined action of corrosion in an aqueous alkaline environment containing H2S, CO2, and tensile stresses (residual or applied).  The cracking is branched and int...
	1A.5 Bending Stress – The variable component of normal stress, the variation may or may not be linear across the section thickness (see Annex 2C).
	1A.6 Bifurcation Buckling – The point of instability where there is a branch in the primary load versus displacement path for a structure (see Annex 2C).
	1A.7 CET (Critical Exposure Temperature) – The CET is defined as the lowest (coldest) metal temperature derived from either the operating or atmospheric conditions at the maximum credible coincident combination of pressure and supplemental loads that ...
	1A.8 COV (Coefficient Of Variation) – A statistical measure of a distribution defined as the ratio of the standard deviation of the distribution to the mean of the distribution.
	1A.9 Corrosion – The deterioration of metal caused by chemical or electrochemical attack as a result of its reaction to the environment (see Part 4).
	1A.10 Crack-Like Flaw – A flaw that may or may not be the result of linear rupture, but which has the physical characteristics of a crack when detected by an NDE technique (see Part 9).
	1A.11 Creep – The special case of inelasticity that characterizes the stress induced time-dependent deformation under load, usually occurring at elevated temperatures (see Part 10).
	1A.12 Creep Damage – In polycrystalline materials (e.g. metals) creep damage results from the motion of dislocations within grains, grain boundary sliding and microstructural diffusion processes within the crystalline lattice.  The resultant grain bou...
	1A.13 Creep Rupture – An extension of the creep process to the limiting condition of gross section failure (frequently termed creep fracture).  The stress that will cause creep fracture at a given time in a specified environment is the creep rupture s...
	1A.14 Cycle – A cycle is a relationship between stress and strain that is established by the specified loading at a location in a vessel or component.  More than one stress-strain cycle may be produced at a location, either within an event or in trans...
	1A.15 Cyclic Loading – The application of repeated or fluctuating stresses, strains, or stress intensities to locations on structural components (see Part 14).
	1A.16 Cyclic Service – A service in which fatigue becomes significant as a result of the cyclic nature of mechanical and/or thermal loads.  A screening criterion is provided in Part 14 that can be used to determine if a fatigue analysis is required as...
	1A.17 Damage Mechanism – A phenomenon that induces deleterious micro and/or macro changes in the material conditions that are harmful to the material condition or mechanical properties.  Damage mechanisms are usually incremental, cumulative, and unrec...
	1A.18 Design Pressure – The pressure used in the design of a pressure component together with the coincident design metal temperature, for the purpose of determining the minimum permissible thickness or physical characteristics of the different zones ...
	1A.19 Ductility – The ability of a material to plastically deform without fracturing.  Ductility is measured as either the reduction in area or elongation in a tensile test specimen.
	1A.20 Elastic Follow-up – A structural behavior where the elastic material surrounding a region with material non-linearity (i.e. plasticity, creep or combined plasticity and creep) results in the region experiencing loading conditions between the ext...
	1A.21 Equipment Design Pressure – The overall design pressure of the pressure equipment or assemblage.  For pressure vessels, it is the design pressure required at the top of the vessel in its operating position.
	1A.22 Equipment  – The maximum permissible pressure of the pressure equipment or assemblage at the designated coincident design metal temperature.  It is the smallest of the values found for maximum allowable working pressure of all the essential part...
	1A.23 Erosion – The destruction of metal by the abrasive action of a liquid or vapor (see Part 4).
	1A.24 Event – The Owner-Users’ Specification may include one or more events that produce fatigue or creep damage.  Each event consists of loading components specified at a number of time points over a time period and is repeated a specified number of ...
	1A.25 exp[x] – The mathematical function .
	1A.26 FAD (Failure Assessment Diagram) – The FAD is used for the evaluation of crack-like flaws in components (see Part 2 and Part 9).
	1A.27 Fatigue – The damage mechanism resulting in fracture under repeated or fluctuating stresses having a maximum value less than the tensile strength of the material (see Part 14).
	1A.28 Fatigue Limit – The fatigue limit or fatigue endurance limit is the highest stress or range of stress that can be repeated indefinitely without failure of the material.
	1A.29 Fatigue Strength – The maximum cyclic stress a material can withstand for a given number of cycles before failure occurs.
	1A.30 Fatigue Strength Reduction Factor – A stress intensification factor which accounts for the effect of a local structural discontinuity (stress concentration) on the fatigue strength.  It is the ratio of the fatigue strength of a component without...
	1A.31 FCA (Future Corrosion Allowance) – The corrosion allowance required for the future operational period of a component.
	1A.32 Fillet Weld – A weld of approximately triangular cross section joining two surfaces approximately at right angles to each other in a lap joint, tee joint, or corner joint.
	1A.33 FFS (Fitness-For-Service) Assessment – A methodology whereby flaws or a damage state in a component is evaluated in order to determine the adequacy of the component for continued operation (see Part 2).
	1A.34 Flaw – A discontinuity, irregularity, or defect that is detected by inspection.
	1A.35 Fracture Mechanics – An engineering discipline concerned with the behavior of cracks in materials.  Fracture mechanics models provide mathematical relationships for critical combinations of stress, crack size and fracture toughness that lead to ...
	1A.36 Girth Weld – A butt weld joining plate sections along the circumferential direction of a cylinder or cone.
	1A.37 Gouge – An elongated local mechanical removal and/or relocation of material from the surface of a component, causing a reduction in wall thickness at the defect; the length of a gouge is much greater than the width and the material may have been...
	1A.38 Groove – A local elongated thin spot caused by directional erosion or corrosion; the length of the metal loss is significantly greater than the width (see Part 5).
	1A.39 Gross Structural Discontinuity – Another name for a Major Structural Discontinuity (see paragraph 1A.54).
	1A.40 Groove-Like Flaw – A surface flaw with a small, but finite, tip (or frontal) radius wherein the flaw length is very much greater than its depth.  Groove-like flaws are categorized as either a groove or gouge (see Part 5 and Part 12).
	1A.41 HAZ (Heat-Affected Zone) – A portion of the base metal adjacent to a weld that has not been melted, but whose metallurgical microstructure and mechanical properties have been changed by the heat of welding, usually with undesirable effects.
	1A.42 HIC (Hydrogen-Induced Cracking) – Stepwise internal cracks that connect adjacent hydrogen blisters on different planes in the metal, or to the metal surface.  An externally applied stress is not needed for the formation of HIC.  In steels, the d...
	1A.43 Hydrogen Blistering – The formation of subsurface planar cavities, called hydrogen blisters, in a metal resulting from excessive internal hydrogen pressure.  Growth of near-surface blisters in low-strength metals usually results in surface bulge...
	1A.44 Inclusion – A discontinuity in a material, usually consisting of a non-metallic compound (oxides, silicate, etc.) encapsulated in a metallic matrix as unintentional impurity.
	1A.45 Incomplete Fusion – Lack of complete melting and coalescence (fusion) of some portion of the metal in a weld joint.
	1A.46 Incomplete Penetration – Partial penetration of the weld through the thickness of the joint.
	1A.47 In-Service Margin – Stated in terms of applied loads, the ratio of the load that will produce a limiting condition to the applied load in the assessed condition.  Similar definitions may be developed for parameters other than load.  For example,...
	1A.48 Jurisdiction – A legally constituted government administration that may adopt rules relating to pressurized components.
	1A.49 Limit Analysis – Limit Analysis is a special case of plastic analysis in which the material is assumed to be ideally plastic (non-strain-hardening).  In limit analysis the equilibrium and flow characteristics at the limit state are used to calcu...
	1A.50 Limit Analysis Collapse Load – The methods of limit analysis are used to compute the maximum load a structure made of an ideally plastic material can carry.  The deformations of an ideally plastic structure increase without bound at this load, w...
	1A.51 Local Primary Membrane Stress – A membrane stress produced by pressure, or other mechanical loading associated with a primary and/or a discontinuity effect would, if not limited, produce excessive distortion in the transfer of load to other port...
	1A.52 Local Structural Discontinuity – A source of stress or strain intensification that affects a relatively small volume of material and does not have a significant effect on the overall stress or strain pattern, or on the structure as a whole.  Exa...
	1A.53 Longitudinal Weld – A full penetration butt weld joining plate sections along the longitudinal axis of a cylinder or cone.
	1A.54 LTA – Locally Thin Area (see Part 5).
	1A.55 Major Structural Discontinuity – A source of stress or strain intensification that affects a relatively large portion of a structure and has a significant effect on the overall stress or strain pattern of the structure as a whole.  Examples are ...
	1A.56 MAT (Minimum Allowable Temperature) – The lowest permissible metal temperature for a given material at a specified thickness based on its resistance to brittle fracture.  It may be a single temperature, or an envelope of allowable operating temp...
	1A.57 MAWP (Maximum Allowable Working Pressure) – The maximum gauge pressure adjusted for liquid head for a component in its operating position at the design temperature, based on calculations using the current minimum thickness, exclusive of thicknes...
	1A.58 MAWPr (Reduced Maximum Allowable Working Pressure) – Reduced maximum allowable working pressure of the damaged component.
	1A.59 Max[a1, a2, a3,.., ai] – The definition of a mathematical function that indicates that the maximum value of all of the arguments, ai, is to be computed.
	1A.60 Membrane Stress – The component of normal stress that is uniformly distributed and equal to the average value of stress across the thickness of the section under consideration (see Annex 2C).
	1A.61 MFH (Maximum Fill Height) – The maximum height permitted for a liquid with a given specific gravity in an atmospheric storage tank at the design temperature based on calculations using the current minimum thickness for all critical shell element...
	1A.62 Min[a1, a2, a3,.., ai] – The definition of a mathematical function that indicates that the minimum value of all of the arguments, ai, is to be computed.
	1A.63 Minimum Allowable Thickness – The thickness required for each element of a vessel based on calculations considering temperature, pressure, and all loadings (see Annex 2B).
	1A.64 MDMT (Minimum Design Metal Temperature) – The lowest temperature at which a significant load can be applied to a pressure vessel as defined by the ASME Code, Section VIII, Division 1 (see Part 3).
	1A.65 MT – Magnetic particle examination.
	1A.66 NDE – Nondestructive examination.
	1A.67 Nil-Ductility Temperature – A temperature at which an otherwise ductile material subject to a load, cracks in a manner characteristic of a brittle fracture.
	1A.68 Normal Stress – The component of stress normal to the plane of reference (this is also referred to as a direct stress).  Usually the distribution of normal stress is not uniform through the thickness of a part, so this stress may be considered t...
	1A.69 Notch Sensitivity – A measure of the reduction in the strength of a metal caused by the presence of a stress concentration.
	1A.70 Notch Toughness – The ability of a material to resist brittle fracture under conditions of high stress concentration, such as impact loading in the presence of a notch.
	1A.71 On-Stream Inspection – The use of any of a number of nondestructive examination procedures to establish the suitability of a pressurized component for continued operation.  The pressurized component may, or may not, be in operation while the ins...
	1A.72 Operational Cycle – An operational cycle is defined as the initiation and establishment of new conditions followed by a return to the conditions that prevailed at the beginning of the cycle.  Three types of operational cycles are considered: the...
	1A.73 Peak Stress – The basic characteristic of a peak stress is that it does not cause any noticeable distortion and is objectionable only as a possible source of a fatigue crack or a brittle fracture.  A stress that is not highly localized falls int...
	1A.74 Pitting – Localized corrosion in the form of a cavity or hole such that the surface diameter of the cavity is on the order of the plate thickness (see Part 6).
	1A.75 Plastic Analysis – A stress analysis method where the structural behavior of a component under load is computed considering the plasticity characteristics of the material including strain hardening and stress redistribution (see Annex 2C).
	1A.76 Plastic Instability Load – The plastic instability load for a structure under predominantly tensile or compressive loading is defined as the load at which unbounded plastic deformation can occur without further load increase.  At the plastic ten...
	1A.77 Plasticity – A general characterization of material behavior in which the material undergoes time independent non-recoverable deformation (see Annex 2C).
	1A.78 POD (Probability Of Detection) – A measure of the ability to detect a flaw or indication in a component using a standard NDE technique on a consistent basis.
	1A.79 Primary Stress – A normal or shear stress developed by the imposed loading that is necessary to satisfy the laws of equilibrium of external and internal forces and moments.  The basic characteristic of a primary stress is that it is not self-lim...
	1A.80 PSF (Partial Safety Factor) – A deterministic parameter (derived from statistical considerations) that represents a level of uncertainty or importance for a specific field variable.  For example, in a fracture mechanics analysis, distinct PSF’s ...
	1A.81 PT – Liquid penetrant examination.
	1A.82 PWHT (Postweld Heat Treatment) – Uniform heating of a weldment to a temperature below the critical range to relieve the major part of the welding residual stresses, followed by uniform cooling in still air.
	1A.83 Ratcheting – A progressive incremental inelastic deformation or strain that can occur in a component subjected to variations of mechanical stress, thermal stress, or both (thermal stress ratcheting is partly or wholly caused by thermal stress). ...
	1A.84 Recognized Code or Standard – A term used to define a code or standard that is recognized by a local jurisdiction (see Part 1, paragraphs 1.2.2 and 1.2.3).
	1A.85 Reference Stress – A quantity that is used to account for plasticity effects in the FAD method.  The reference stress is computed by multiplying the primary stress by a dimensionless factor that is a function of the component geometry and crack ...
	1A.86 Repair – Restoration of a pressure containing component, the definition is dependent on the equipment type as shown below:
	1A.87 Rerating – A change in either or both the temperature rating and the maximum allowable working pressure rating of a vessel (see Part 2).
	1A.88  (Remaining Strength Factor) – The ratio of the collapse pressure of a damaged component (e.g. cylinder containing an LTA) to the collapse pressure of the undamaged component (see Part 2).
	1A.89 RT – Radiographic examination.
	1A.90 Secondary Stress – A normal stress or a shear stress developed by the constraint of adjacent parts or by self-constraint of a structure.  The basic characteristic of a secondary stress is that it is self-limiting.  Local yielding and minor disto...
	1A.91 Sensitivity Analysis – A statistical or parametric process of varying the independent variables (or inputs) in order to determine the response (or sensitivity) of the dependent variables (or outputs).  For example, in a Fitness-For-Service analy...
	1A.92 Shakedown – A process caused by cyclic loads or cyclic temperature distributions which produce plastic deformations in some regions of the component when the loading or temperature distribution is applied, but upon removal of the loading or temp...
	1A.93 Shear Stress – The component of stress tangent to the plane on which forces act (see Annex 2C).
	1A.94 Shock Chilling – Shock chilling is a rapid decrease in metal temperature caused by the sudden contact of liquid or a two-phase (gas/liquid) fluid with a metal surface when the liquid or two phase fluid is colder than the metal temperature at the...
	1A.95 SOHIC (Stress-Oriented Hydrogen-Induced Cracking) – Arrays of cracks that are aligned nearly perpendicular to the applied stress, which is formed by the link-up of small HIC cracks in steel.  Tensile stress (residual or applied) is required to p...
	1A.96 Strain Limiting Load – The load associated with a given strain limit (see Annex 2C).
	1A.97 Stress Concentration Factor – A multiplying factor applied stress equal to the ratio of the maximum stress to the average section stress (see Annex 2C).
	1A.98 Stress Cycle – A stress cycle is a condition in which the alternating stress difference goes from an initial value through an algebraic maximum value and an algebraic minimum value and then returns to the initial value.  A single operational cyc...
	1A.99 Stress Intensity Factor – The stress intensity factor is used in fracture mechanics to predict the stress state or stress intensity near the tip of a crack in a linear elastic body caused by a remote loading or residual stresses (see Part 9 and ...
	1A.100 SSC (Sulfide Stress Cracking) – Cracking of a metal under the combined action of tensile stress and corrosion in the presence of water and H2S (a form of hydrogen stress cracking).  SSC involves hydrogen embrittlement of the metal by atomic hyd...
	1A.101 Tensile Strength – The maximum load per unit of original cross sectional area that a tensile test specimen of a material sustains prior to fracture.  The tensile strength may also be identified as the ultimate tensile strength (see Annex 2D).
	1A.102 Thermal Stress – A self-balancing stress produced by a nonuniform distribution of temperature or by differing thermal coefficients of expansion.  Thermal stress is developed in a solid body whenever a volume of material is prevented from assumi...
	1A.103 Toughness – The ability of a material to absorb energy and deform plastically before fracturing (see Annex 9F).
	1A.104 Transition Temperature – The temperature at which a material fracture mode changes from ductile to brittle (see Annex 9F).
	1A.105 Undercut – An intermittent or continuous groove, crater or channel that has melted below, and thus undercut, the surface of the base metal adjacent to the toe of a weld and is left unfilled by weld metal.
	1A.106 UT – Ultrasonic examination.
	1A.107 Volumetric Flaw – A flaw characterized by a loss of material volume or by a shape imperfection.  Examples include general and local corrosion, pitting, blisters, out-of-roundness, bulges, dents, gouges, and dent-gouge combinations, and weld mis...
	1A.108 Weld – A localized coalescence of metal wherein coalescence (i.e. fusion) is produced by heating to suitable temperatures, with or without the application of pressure, and with or without the use of filler metal.  If a filler metal is used, it ...
	1A.109 Yield Strength – The stress at which a material exhibits a specified deviation from the linear proportionality of stress versus strain (see Annex 2E).
Part 2  – Fitness-For-Service Engineering Assessment Procedure
	2.1 General
		2.1.1 Fitness-For-Service and Continued Operation
		2.1.2 Organization by Flaw Type and Damage Mechanism
		2.1.3 FFS Assessment Procedure
	2.2 Applicability and Limitations of the FFS Assessment Procedures
		2.2.1 FFS Procedures for Pressurized or Unpressurized Components
		2.2.2 Component Definition
		2.2.3 Construction Codes
		2.2.4 Specific Applicability and Limitations
	2.3 Data Requirements
		2.3.1 Original Equipment Design Data
			2.3.1.1 The following original equipment design data should be assembled to perform a  assessment.  The extent of the data required depends on the damage mechanism and assessment level.  A data sheet is included in Table 2.2 to record the required inf...
			2.3.1.2 If some of these data are not available, physical measurements or field inspection of the component should be made to provide the information necessary to perform the assessment.
		2.3.2 Maintenance and Operational History
			2.3.2.1 A progressive record including, but not limited to, the following should be available for the equipment being evaluated.  The extent of the data required depends on the damage mechanism and assessment level.
			2.3.2.2 If some of these data are not available, physical measurements should be made to provide the information necessary to perform the assessment.
		2.3.3 Required Data/Measurements for a FFS Assessment
			2.3.3.1 Each Part in this Standard that contains  assessment procedures includes specific requirements for data measurements and flaw characterization based on the damage mechanism being evaluated.  Examples of flaw characterization include thickness ...
			2.3.3.2 The Future Corrosion Allowance () should be established for the intended future operating period.  The  should be based on past inspection information or corrosion rate data relative to the component material in a similar environment.  Corrosi...
		2.3.4 Recommendations for Inspection Technique and Sizing Requirements
	2.4 Assessment Techniques and Acceptance Criteria
		2.4.1 Assessment Levels
			2.4.1.1 Level 1 Assessment
			2.4.1.2 Level 2 Assessment
			2.4.1.3 Level 3 Assessment
		2.4.2 FFS Acceptance Criteria
			2.4.2.1 Allowable Stress
			2.4.2.2 Remaining Strength Factor
			2.4.2.3 Failure Assessment Diagram
		2.4.3 Data Uncertainties
			2.4.3.1 Sensitivity Analysis
			2.4.3.2 Probabilistic Analysis
			2.4.3.3 Partial Safety Factors
	2.5 Remaining Life Assessment
		2.5.1 Remaining Life
		2.5.2 Guidance on Remaining Life Determination
	2.6 Remediation
		2.6.1 Requirements for Remediation
		2.6.2 Guidelines for Remediation
	2.7 In-Service Monitoring
	2.8 Documentation
		2.8.1 General
		2.8.2 Applicability and Limitations
		2.8.3 Data Requirements
		2.8.4 Assessment Techniques and Acceptance Criteria
		2.8.5 Remaining Life Assessment
		2.8.6 Remediation Methods
		2.8.7 In-Service Monitoring
		2.8.8 Retention
	2.9 Nomenclature
	2.10 References
	2.11 Tables
	2.12 Figures
Annex 2A  – Technical Basis and Validation – Fitness-For-Service Engineering Assessment Procedure
	2A.1 Technical Basis and Validation
	2A.2 References
Annex 2B – Damage Mechanisms
	2B.1 Deterioration and Failure Modes
	2B.2 FFS Assessment and the Identification of Damage Mechanisms
	2B.3 Pre-Service Deficiencies
		2B.3.1 Types of Pre-service Deficiencies
		2B.3.2 In-Service Inspection
			2B.3.2.1 In most instances, one or more of these pre-service deficiencies do not lead to an immediate failure.  Usually, only gross errors cause a failure during a pre-service hydrostatic or pneumatic test.
			2B.3.2.2 Flaws or damage associated with pre-service deficiencies or damage are often only discovered during an In-Service Inspection (ISI), because in many cases the ISI techniques used are more sensitive or the inspection scope is wider than the ins...
	2B.4 In-Service Deterioration and Damage
		2B.4.1 Overview
			2B.4.1.1 Once equipment enters service, it is subjected to operating and/or downtime conditions that can deteriorate or damage the equipment.  One factor that complicates a  analysis is that material/environmental condition interactions are extremely ...
			2B.4.1.2 Each general type of damage is caused by a multitude of damage mechanisms, which are specific types of corrosion (e.g. naphthenic acid corrosion of carbon steel), stress corrosion cracking (SCC – e.g. polythionic acid stress corrosion crackin...
			2B.4.1.3 The following sections of this Annex describe each of the damage types and provide some typical examples of damage mechanisms and potential mitigation methods.  These sections are intended to introduce the concepts of service-induced deterior...
			2B.4.1.4 When performing a  assessment it is important that the potential for further damage is considered or that steps are taken to preclude further damage from occurring by means of mitigation methods.  A list of the types of information needed for...
		2B.4.2 General Metal Loss Due to Corrosion and/or Erosion
			2B.4.2.1 General metal loss is defined as relatively uniform thinning over a significant area of the equipment (see Part 4).  Examples of general corrosion for carbon steel and low alloy steels are sulfidation in crude units, H2/H2S corrosion in hydro...
			2B.4.2.2 A corrosion rate can usually be calculated from past and current thickness readings, for example see API 510, API 570, and API 653.  The corrosion rate can also be predicted from standard corrosion curves/references, such as the modified McCo...
			2B.4.2.3 Remediation and monitoring methods for general metal loss are described in Part 4.
		2B.4.3 Localized Metal Loss Due to Corrosion and/or Erosion
			2B.4.3.1 Unlike general metal loss, localized metal loss rates can vary significantly within a given area of the equipment.  Examples of localized metal loss are under deposit corrosion in crude unit overhead systems, naphthenic acid corrosion, inject...
			2B.4.3.2 When localized metal loss is detected, it is important to locate and characterize all of the locally thinned areas and obtain accurate measurements to calculate a metal loss rate.  Predicting a localized corrosion rate is difficult, since the...
			2B.4.3.3 Remediation and monitoring methods for local metal loss are described in Part 5.
		2B.4.4 Surface Connected Cracking
			2B.4.4.1 Most service-induced cracking mechanisms initiate at the surface of the component.  Examples of service-induced surface cracking are mechanical and thermal fatigue and various forms of Stress Corrosion Cracking (SCC), such as polythionic acid...
			2B.4.4.2 The occurrence of SCC requires a combination of three conditions to be present: a susceptible material or material condition, a chemically aggressive environment, and a sufficiently high tensile stress.  Since three factors are involved, gene...
			2B.4.4.3 The metallurgical condition of the material is an important determinant of the severity of the SCC problem.  For example, high hardness and strength make steel, particularly the HAZ of welds, more susceptible to sulfide stress cracking.  Anot...
			2B.4.4.4 Surface cracks often are found by surface inspection techniques, such as visual, PT and MT, although UT methods and AET are also used to detect cracks.  Sizing surface connected cracking, in particular SCC, is very difficult, because in many ...
			2B.4.4.5 Predicting crack growth rates for SCC is also very difficult, because of a lack of relevant data and lack of precise knowledge of the environmental conditions near the crack tip, which can be different from the bulk stream composition.  SCC i...
			2B.4.4.6 Mitigation methods to slow/prevent further SCC without removing cracks are somewhat limited.  Strip lining the area and possibly coating the area if the cracks are tight is possible.  Other methods are to alter the environment by means of che...
			2B.4.4.7 If cracks are removed, additional mitigation options are available, such as PWHT or heat treatment to remove residual stresses and/or improve the metallurgical condition such as grain refining, weld overlays and coatings to isolate the suscep...
		2B.4.5 Subsurface Cracking and Microfissuring/Microvoid Formation
			2B.4.5.1 Service-induced damage that is not surface connected or initiates subsurface cracking falls into the general class of low-temperature hydrogen related phenomena or high temperature mechanisms such as creep and hydrogen attack.  Hydrogen damag...
			2B.4.5.2 This mechanism is similar to SCC in that susceptible material and an aggressive environment must be present.  Hydrogen blistering and HIC are however, not stress related, but SOHIC is.  Hydrogen damage often is an on/off mechanism, occurring ...
			2B.4.5.3 Metallurgical and microstructural details (e.g. the sulfur impurity level of the steel) affect the susceptibility to damage or threshold level for damage by a certain level of hydrogen charging.  Environmental variables, such as pH, temperatu...
			2B.4.5.4 Finding subsurface hydrogen damage is normally accomplished by visual inspection and various UT methods.  Assessing the damage is very difficult because this is more a damage mechanics than fracture mechanics problem, since there often is no ...
			2B.4.5.5 Mitigation for low temperature hydrogen damage can consist of chemical treatment and/or water washing to minimize hydrogen charging, strip lining or coatings to isolate the steel from the environment, and venting for blisters to relieve the i...
			2B.4.5.6 Creep and/or high temperature hydrogen attack (HTHA) are mechanisms that form voids and fissuring only during latter stages of damage.  These mechanisms can be either surface-connected or initiate subsurface.  The variables that affect creep ...
		2B.4.6 Metallurgical Changes
			2B.4.6.1 Metallurgical properties, such as strength, ductility, toughness, and corrosion resistance can change while a component is in-service due to microstructural changes because of thermal aging at elevated temperatures.  In addition, properties c...
			2B.4.6.2 These changes in properties are often difficult to detect, since damage may not have occurred yet.  Sometimes inferences can be made from examining samples or surface replicas.  Steel composition and microstructure, operating temperature, and...
			2B.4.6.3 Once the metallurgical properties are changed in-service, they usually are not recoverable.  Heat treatment can be effective, although this often is only a temporary solution.  To prevent further damage or degradation to metallurgical propert...
			2B.4.6.4 As previously discussed, loss of toughness can occur in service because of the process environment and service conditions.  This form of metallurgical damage will have significant impact on the structural integrity of a component containing a...
	2B.5 References
	2B.6   Tables
Annex 2C – Thickness, MAWP And Stress Equations For A FFS Assessment
	2C.1 General
		2C.1.1 Scope
		2C.1.2 MAWP and MFH
		2C.1.3 Construction Codes and Common Rules
		2C.1.4 Use of VIII-2 Design Equations
	2C.2 Calculation of tmin, MAWP (MFH), and Membrane Stress
		2C.2.1 Overview
		2C.2.2 Minimum Required Wall Thickness and MAWP (MFH)
		2C.2.3 Code Revisions
		2C.2.4 Determination of Allowable Stresses
		2C.2.5 Treatment of Weld and Riveted Joint Efficiency, and Ligament Efficiency
		2C.2.6 Treatment of Damage in Formed Heads
		2C.2.7 Thickness for Supplemental Loads
			2C.2.7.1 Supplemental loads, may result in an axial force and/or bending moment being applied to the end of a cylindrical shell, conical shell or pipe section.  This type of loading results in longitudinal membrane and bending stresses (stresses actin...
			2C.2.7.2 The thickness necessary for supplemental loads shall be considered in the determination of the minimum thickness, ,  or , and/or membrane stress.
			2C.2.7.3 Two Options are provided for evaluating supplemental loads on vertical vessels.
			2C.2.7.4 The thickness for supplemental loads may be computed using VIII-2, Part 4, paragraph 4.15.
			2C.2.7.5 Typically,  is not explicitly calculated for piping systems because of the relationship between the component thickness, piping flexibility or stiffness, and applied loading, both sustained and thermal.  When evaluating requirements for suppl...
		2C.2.8 Determination of Metal Loss and Future Corrosion Allowance
		2C.2.9 Treatment of Metal Loss and Future Corrosion Allowance
		2C.2.10 Treatment of Shell Distortions
	2C.3 Pressure Vessels and Boiler Components – Internal Pressure
		2C.3.1 Overview
		2C.3.2 Shell Tolerances
		2C.3.3 Cylindrical Shells
		2C.3.4 Spherical Shell or Hemispherical Head
		2C.3.5 Elliptical Head
		2C.3.6 Torispherical Head
		2C.3.7 Conical Shell
		2C.3.8 Toriconical Head
		2C.3.9 Conical Transition
		2C.3.10 Nozzles Connections in Shells
		2C.3.11 Junction Reinforcement Requirements at Conical Transitions
		2C.3.12 Other Components
	2C.4 Pressure Vessels and Boiler Components – External Pressure
	2C.5 Piping Components and Boiler Tubes
		2C.5.1 Overview
		2C.5.2 Metal Loss
		2C.5.3 Required Thickness and MAWP – Straight Pipes Subject To Internal Pressure
		2C.5.4 Required Thickness and MAWP – Boiler Tubes
		2C.5.5 Required Thickness and MAWP – Pipe Bends Subject To Internal Pressure
		2C.5.6 Required Thickness and MAWP for External Pressure
		2C.5.7 Branch Connections
	2C.6 API 650 Storage Tanks
		2C.6.1 Overview
		2C.6.2 Metal Loss
		2C.6.3 Required Thickness and MFH for Liquid Hydrostatic Loading
	2C.7 Nomenclature
	2C.8 References
	2C.9  Tables
	2C.10 Figures
Annex 2D – Stress Analysis Overview For A FFS Assessment
	2D.1 General Requirements
		2D.1.1 Scope
		2D.1.2 ASME B&PV Code, Section VIII, Division 2 (VIII-2)
		2D.1.3 Applicability
		2D.1.4 Protection Against Failure Modes
		2D.1.5 Numerical Analysis
		2D.1.6 Material Properties
		2D.1.7 Applicable Loads and Load Case Combinations
		2D.1.8 Loading Histogram
	2D.2 Protection Against Plastic Collapse
		2D.2.1 Overview
		2D.2.2 Elastic Stress Analysis Method
		2D.2.3 Limit-Load Analysis Method
		2D.2.4 Elastic-Plastic Stress Analysis Method
		2D.2.5 Treatment of the Weld Joint Efficiency
	2D.3 Protection Against Local Failure
		2D.3.1 Overview
		2D.3.2 Elastic Analysis Method
		2D.3.3 Elastic-Plastic Analysis Method
	2D.4 Protection Against Collapse From Buckling
		2D.4.1 Assessment Procedure
		2D.4.2 Supplemental Requirements for Components with Flaws
	2D.5 Supplemental Requirements for Stress Classification in Nozzle Necks
	2D.6 Nomenclature
	2D.7 References
	2D.8  Tables
Annex 2E – Material Properties For Stress Analysis
	2E.1 General
		2E.1.1 Material Properties Required
		2E.1.2 Material Properties and In-Service Degradation
	2E.2 Strength Parameters
		2E.2.1 Yield and Tensile Strength
			2E.2.1.1 Estimates for the material yield strength and tensile strength to be used in an  assessment may be obtained as follows:
			2E.2.1.2 Analytical expressions for the minimum specified yield strength as a function of temperature and the applicable temperature range are provided in Table 2E.2.  The minimum specified yield strength at a temperature is determined by multiplying ...
			2E.2.1.3 Analytical expressions for the minimum specified ultimate tensile strength as a function of temperature and the applicable temperature range are provided in Table 2E.4.  The minimum specified ultimate tensile strength at a temperature is dete...
			2E.2.1.4 A method to compute the yield and tensile strength as a function of temperature for pipe and tube materials is provided in Table 2E.6.  The data used to develop these equations are from API Std 530, 6th Edition, September 2008.  The yield and...
			2E.2.1.5 Values for the yield and tensile strength below the creep regime for pressure vessel, piping, and tankage steels can be found in the ASME Code, Section II, Part D.  Other sources for yield and tensile strength data for various materials are p...
		2E.2.2 Flow Stress
			2E.2.2.1 The flow stress, , can be thought of as the effective yield strength of a work hardened material.  The use of a flow stress concept permits the real material to be treated as if it were an elastic-plastic material that can be characterized by...
			2E.2.2.2 Several relationships for estimating the flow stress have been proposed which are summarized below.  The flow stress to be used in an assessment will be covered in the appropriate Part of this Standard.  In the absence of a material test repo...
	2E.3 Monotonic Stress-Strain Relationships
		2E.3.1 MPC Stress-Strain Curve Model
		2E.3.2 MPC Tangent Modulus Model
		2E.3.3 Ramberg-Osgood Model
		2E.3.4 Ramberg-Osgood Tangent Modulus Model
	2E.4 Cyclic Stress-Strain Relationships
		2E.4.1 Ramberg-Osgood
		2E.4.2 Uniform Material Law
	2E.5 Physical Properties
		2E.5.1 Elastic Modulus
		2E.5.2 Poisson’s Ratio
		2E.5.3 Coefficient of Thermal Expansion
		2E.5.4 Thermal Conductivity
		2E.5.5 Thermal Diffusivity
		2E.5.6 Density
	2E.6 Nomenclature
	2E.7 References
		2E.7.1 Strength Parameters
		2E.7.2 Cyclic Stress-Strain Relationships
		2E.7.3 Physical Properties
	2E.8  Tables
Annex 2F  – Alternative Method For Establishing the Remaining Strength Factor
	2F.1 Overview
	2F.2 Establishing an Allowable Remaining Strength Factor – RSFa
	2F.3 Nomenclature
	2F.4 References
Part 3  – Assessment Of Existing Equipment For Brittle Fracture
	3.1 General
		3.1.1 Evaluation of Resistance to Brittle Fracture
		3.1.2 Avoidance of Catastrophic Brittle Fracture
		3.1.3 Boilers and Boiler External Piping
		3.1.4 Supplemental Brittle Fracture Assessment to Other FFS Assessment Procedures
		3.1.5 Critical Exposure Temperature (CET)
		3.1.6 Minimum Allowable Temperature (MAT)
	3.2 Applicability and Limitations of the Procedure
		3.2.1 Equipment Covered
		3.2.2 Components Subject to Metal Loss
		3.2.3 Requirements for In-Service Inspection and Maintenance Programs
	3.3 Data Requirements
		3.3.1 Original Equipment Design Data
		3.3.2 Maintenance and Operational History
		3.3.3 Required Data/Measurements for a FFS Assessment
		3.3.4 Recommendations for Inspection Technique and Sizing Requirements
	3.4 Assessment Techniques and Acceptance Criteria
		3.4.1 Overview
		3.4.2 Level 1 Assessment
			3.4.2.1 Pressure Vessels
			3.4.2.2 Piping Systems
			3.4.2.3 Atmospheric and Low Pressure Storage Tanks
			3.4.2.4 If the component does not meet the Level 1 Assessment requirements, then a Level 2 or Level 3 Assessment can be performed.
		3.4.3 Level 2 Assessment
			3.4.3.1 Pressure Vessels – Method A
			3.4.3.2 Pressure Vessels – Method B
			3.4.3.3 Pressure Vessels – Method C
			3.4.3.4 Piping Systems – Method A
			3.4.3.5 Piping Systems – Method B
			3.4.3.6 Piping Systems – Method C
			3.4.3.7 Atmospheric and Low Pressure Storage Tanks
			3.4.3.8 If the component does not meet the Level 2 Assessment requirements, then a Level 3 Assessment can be performed.
		3.4.4 Level 3 Assessment
			3.4.4.1 Pressure vessels, piping and tankage that do not meet the criteria for Level 1 or 2 assessments can be evaluated using a Level 3 assessment.  Level 3 assessments normally involve more detailed determinations of one or more of the three factors...
			3.4.4.2 Part 9 may be used as a basis for a Level 3 Assessment.  A risk analysis considering both the probability and potential consequences of a brittle fracture in the specific service should also be considered in a Level 3 Assessment.
			3.4.4.3 At this assessment level, the judgment of the engineer involved (see Part 1, paragraph 1.4.3) may be used to apply some of the principles of Levels 1 and 2 without the specific restrictions used at those levels.  Examples of some other approac...
			3.4.4.4 It may be necessary to evaluate stresses using advanced techniques such as finite element analysis.  Consideration should be given to all relevant loads including those that produce localized stresses (e.g. forces and moments at nozzles), ther...
			3.4.4.5 A Level 3 assessment normally relies on a determination of maximum expected flaw sizes at locations of high stresses.  In general, these postulated flaws should be assumed to be surface breaking, and to be oriented transverse to the maximum st...
			3.4.4.6 The use of material toughness data from appropriate testing is the preferred basis for a Level 3 assessment.  Where this is not practical, appropriate and sufficiently conservative estimates should be made.  Methods for obtaining or estimating...
	3.5 Remaining Life Assessment
		3.5.1 Acceptability for Continued Service
		3.5.2 Pressure Vessels
		3.5.3 Piping Systems
		3.5.4 Atmospheric and Low Pressure Storage Tanks
	3.6 Remediation
		3.6.1 Potential Use of Remediation Methods
		3.6.2 Remediation Methods
			3.6.2.1 Limiting Operation – The limitation of operating conditions to within the acceptable operating pressure-temperature envelope is the simplest type of remediation effort.  This method, however, may be impractical in many cases because of the req...
			3.6.2.2 Postweld Heat Treatment (PWHT) – If the component has not been subject to PWHT, PWHT may be performed to enhance the damage tolerance to crack-like flaws and resistance to brittle fracture.  The effects of PWHT are described below.
			3.6.2.3 Hydrostatic Test – If the component has not been subject to a hydrotest, then a hydrotest may be performed to enhance the damage tolerance to crack-like flaws and resistance to brittle fracture.  The beneficial effect of a hydrotest is that cr...
	3.7 In-Service Monitoring
		3.7.1 In-Service Monitoring and Control of Process Conditions
		3.7.2 Monitoring for Degradation of Low Alloy Steel Notch Toughness
		3.7.3 Monitoring for Criticality of Growing Flaws
		3.7.4 Assessment of Non-Growing Flaws Detected In-Service
	3.8 Documentation
		3.8.1 Documentation Requirements for Each Assessment Level
			3.8.1.1 Level 1 Assessment – Documentation covering the assessment, the specific data used, and the criteria that have been met by the results obtained from the evaluation.
			3.8.1.2 Level 2 Assessment – The documentation should address the reason(s) for the assessment, the assessment level used, the engineering principles employed, the source of all material data used, identification of any potential material property deg...
			3.8.1.3 Level 3 Assessment – The documentation should cover the reason(s) for performing a Level 3 assessment and all issues pertaining to the Fitness-For-Service assessment.  The documentation should also address the engineering principles employed i...
		3.8.2 Documentation Retention
	3.9 Nomenclature
	3.10 References
	3.11  Tables
	3.12 Figures
Annex 3A   – Technical Basis and Validation – Assessment Of Existing Equipment For Brittle Fracture
	3A.1 Technical Basis and Validation
	3A.2 References
Part 4  – Assessment Of General Metal Loss
	4.1 General
		4.1.1 Assessment Procedures for General Metal Loss
		4.1.2 Thickness Averaging Approach Used For the Assessment
	4.2 Applicability and Limitations of the Procedure
		4.2.1 General Metal Loss Assessment
		4.2.2 Limitations Based on Flaw Type
		4.2.3 Calculation of the MAWPr and MFHr and Coincident Temperature
		4.2.4 Limitations Based on Temperature
		4.2.5 Definition of Component Types
		4.2.6 Applicability of the Level 1 and Level 2 Assessment Procedures
		4.2.7 Applicability of the Level 3 Assessment Procedures
	4.3 Data Requirements
		4.3.1 Original Equipment Design Data
		4.3.2 Maintenance and Operational History
		4.3.3 Required Data/Measurements for a FFS Assessment
			4.3.3.1 Thickness readings are required on the component where the metal loss has occurred to evaluate general metal loss.  An overview of the Level 1 and Level 2 assessment options are shown in Figure 4.2, and are described in paragraph 4.4.
			4.3.3.2 If point thickness readings are used in the assessment, the assumption of uniform metal loss should be confirmed.
			4.3.3.3 If thickness profiles are used in the assessment, the following procedure shall be used to determine the required inspection locations and the Critical Thickness Profiles (CTPs).
			4.3.3.4 If the region of metal loss is close to or at a major structural discontinuity, the remaining thickness can be established using the procedure in paragraph 4.3.3.2 or 4.3.3.3.  However, additional thickness readings should be taken to include ...
			4.3.3.5 Additional thickness readings are required if discrepancies are noted in the reported thickness measurements.  For example, if the latest thickness reading is greater than the reading at the time of the last inspection, additional readings may...
		4.3.4 Recommendations for Inspection Technique and Sizing Requirements
			4.3.4.1 Thickness readings can be made using straight beam ultrasonic thickness examination (UT).  This method can provide high accuracy and can be used for point thickness readings and in obtaining thickness profiles.  Continuous line scans or area s...
			4.3.4.2 Obtaining accurate thickness readings using UT depends on the surface condition of the component.  Surface preparation techniques vary depending on the surface condition, but in many cases, wire brushing is sufficient.  However, if the surface...
			4.3.4.3 All UT thickness readings should be made after proper calibration for the wall thickness, ultrasonic velocity and temperature ranges of the component.  Special UT couplants are required if the thickness readings are obtained on high temperatur...
			4.3.4.4 Radiographic examination (RT) may also be used to determine metal loss; however, accurate thickness data may only be obtained by moving the component containing the metal loss, or moving the source around the component to obtain multiple views...
	4.4 Assessment Techniques and Acceptance Criteria
		4.4.1 Overview
			4.4.1.1 If the metal loss is less than the specified corrosion/erosion allowance and adequate thickness is available for the future corrosion allowance, no further action is required other than to record the data; otherwise, an assessment is required.
			4.4.1.2 An overview of the assessment levels is provided in Figure 4.1.
			4.4.1.3 If thickness readings indicate that the metal loss is localized and thickness profiles are obtained, the assessment procedures in this Part can still be used for the assessment.  However, the results may be conservative, and the option for per...
			4.4.1.4  assessments for the components listed below require special consideration because of the complexities associated with the design requirements of the original construction code.  In each case, an Engineer knowledgeable and experienced in the d...
		4.4.2 Level 1 Assessment
			4.4.2.1 The following assessment procedure shall be used to evaluate Type A Components (see paragraph 4.2.5) subject to internal or external pressure when Point Thickness Reading (PTR) data are used to characterize the metal loss (see paragraph 4.3.3.2).
			4.4.2.2 The following assessment procedure shall be used to evaluate Type A Components (see paragraph 4.2.5) subject to internal or external pressure when Critical Thickness Profile (CTP) data are used to characterize the metal loss (see paragraph 4.3...
			4.4.2.3 If the component does not meet the Level 1 Assessment requirements (see Part 2, paragraph 2.4.2.2.e), then the following, or combinations thereof, shall be considered:
		4.4.3 Level 2 Assessment
			4.4.3.1 The assessment procedure in paragraph 4.4.2.1 may be used to evaluate Type A and Type B Class 1 Components (see paragraph 4.2.5) subject to internal pressure, external pressure, supplemental load or combined loads when Point Thickness Reading ...
			4.4.3.2 The assessment procedure in paragraph 4.4.2.2 may be used to evaluate Type A and Type B Class 1 Components (see paragraph 4.2.5) subject to internal pressure, external pressure, supplemental load or combined loads when Critical Thickness Profi...
			4.4.3.3 The following assessment procedure can be used to evaluate Type B Class 2 Components (see paragraph 4.4.1.2.b) subject to internal pressure or external pressure load.
			4.4.3.4 If the component does not meet the Level 2 Assessment requirements, then the following, or combinations thereof, can be considered:
		4.4.4 Level 3 Assessment
			4.4.4.1 The stress analysis techniques discussed in Annex 2D can be utilized to evaluate regions of general or local metal loss in pressure vessels, piping, and tanks.  The finite element method is typically used to compute the stresses in a component...
			4.4.4.2 If a component is subject to external pressure and/or other loads that result in compressive stresses, a structural stability analysis should be performed using the methods in Annex 2D to determine suitability for continued service.  In additi...
			4.4.4.3 Thickness data per paragraph 4.3.3 as well as the component geometry, material properties and loading conditions are required for a Level 3 Assessment.  The thickness data can be used directly in finite element model of the component.  If thic...
			4.4.4.4 If the region of local metal loss is close to or at a major structural discontinuity, details of the component geometry, material properties, and imposed supplemental loads (see Annex 2C, paragraph 2C.2.6) at this location are required for the...
	4.5 Remaining Life Assessment
		4.5.1 Thickness Approach
			4.5.1.1 The remaining life of a component can be determined based upon computation of a minimum required thickness for the intended service conditions according to Table 4.4, Table 4.5, Table 4.6, or Table 4.7, thickness measurements from an inspectio...
			4.5.1.2 The remaining life determined using the Thickness Approach may produce non-conservative results when applied to Type B Class 2 or Type C Components (see paragraph 4.2.5).  For these cases, the remaining life should be established using the  ap...
		4.5.2 MAWP Approach
			4.5.2.1 The  approach provides a systematic method for determining the remaining life of Type A, B, and C components (see Annex 4A, reference [2]).  This method is also the only method suitable for determining the remaining life of Type B and C compon...
			4.5.2.2 The following procedure can be used to determine the remaining life of a component using the  approach.
			4.5.2.3 This approach may also be applied to tanks using the maximum fill height, , instead of the .
	4.6 Remediation
		4.6.1 Objectives
		4.6.2 Methods
			4.6.2.1 Remediation Method 1 – Performing Physical Changes to the Process Stream; the following can be considered.
			4.6.2.2 Remediation Method 2 – Application of solid barrier linings or coatings to keep the environment isolated from the base metal that has experienced previous damage.
			4.6.2.3 Remediation Method 3 – Injection of water and/or chemicals on a continuous basis to modify the environment or the surface of the metal.  Important variables to consider when injecting chemicals are: the particular stream contaminants, injectio...
			4.6.2.4 Remediation Method 4 – Application of weld overlay for repair of the base material or for the addition of a corrosion resistant lining.  If weld overlay is applied, the weldability of the base metal considering the effects of the environment s...
	4.7 In–Service Monitoring
		4.7.1 Objectives
		4.7.2 Monitoring Methods
		4.7.3 Calibration
	4.8 Documentation
		4.8.1 General
		4.8.2 Inspection Data
	4.9 Nomenclature
	4.10 References
	4.11  Tables
	4.12 Figures
Annex 4A  – Technical Basis and Validation – Assessment Of General Metal Loss
	4A.1 Technical Basis and Validation
	4A.2 References
Part 5  – Assessment Of Local Metal Loss
	5.1 General
		5.1.1 Assessment Procedures for Local Metal Loss
		5.1.2 Choice of Part 4 or Part 5 Assessment Procedures
		5.1.3 Pitting Damage
	5.2 Applicability and Limitations of the Procedure
		5.2.1 Local Metal Loss Assessment
		5.2.2 Limitations Based on Flaw Type
		5.2.3 Calculation of the MAWPr and MFHr and Coincident Temperature
		5.2.4 Limitations Based on Temperature
		5.2.5 Applicability of the Level 1 and Level 2 Assessment Procedures
		5.2.6 Applicability of the Level 3 Assessment Procedures
		5.2.7 Assessment of Blend Ground Areas for Crack-Like Flaw Removal
	5.3 Data Requirements
		5.3.1 Original Equipment Design Data
		5.3.2 Maintenance and Operational History
		5.3.3 Required Data/Measurements for a FFS Assessment
			5.3.3.1 To assess local corrosion/erosion, thickness readings are required on the component in the area where the metal loss has occurred.  If the metal loss is less than the specified corrosion/erosion allowance and adequate thickness is available fo...
			5.3.3.2 The following information is required for a Level 1 and Level 2 Assessment.
			5.3.3.3 The information required to perform a Level 3 Assessment depends on the analysis method utilized.  In general, a limit load procedure using a numerical technique can be used to establish the acceptable operating or design conditions as appropr...
		5.3.4 Recommendations for Inspection Technique and Sizing Requirements
			5.3.4.1 Recommendations for obtaining thickness measurements to characterize the local metal loss are covered in Part 4, paragraph 4.3.4.
			5.3.4.2 The radius at the base of the groove-like flaw can be established by using a profile gauge.  Alternatively, a mold can be made of the flaw using clay or a similar material and the radius can be directly determined from the mold.
			5.3.4.3 In addition to thickness readings to establish the thickness profile, the following examination is recommended:
	5.4 Assessment Techniques and Acceptance Criteria
		5.4.1 Overview
			5.4.1.1 If the metal loss is less than the specified corrosion/erosion allowance and adequate thickness is available for the future corrosion allowance, no further action is required other than to record the data; otherwise, an assessment is required.
			5.4.1.2 An overview of the assessment levels is provided in Figure 5.1.
		5.4.2 Level 1 Assessment
			5.4.2.1 The Level 1 Assessment procedures can be used to evaluate a Type A Component with local metal loss subject to internal pressure.  The procedures can be used to determine acceptability and/or to rerate a component with a flaw.  If there are sig...
			5.4.2.2 The procedure shown below is developed for pressurized components where an  can be determined.  For an atmospheric storage tank, the same procedure can be followed to determine a  by replacing the  with the , and determining the  using the app...
			5.4.2.3 If the equipment is not acceptable for continued operation per Level 1 Assessment requirements, then the following, or combinations thereof, shall be considered:
		5.4.3 Level 2 Assessment
			5.4.3.1 The Level 2 Assessment procedures provide a better estimate of the Remaining Strength Factor than the Level 1 procedure for local metal loss in a component subject to internal pressure if there are significant variations in the thickness profi...
			5.4.3.2 The following assessment procedure can be used to evaluate Type A Components subject to internal pressure (see paragraph 5.2.5.d).  The procedure shown below is developed for pressurized components where a  can be determined.  For an atmospher...
			5.4.3.3 The following assessment procedure can be used to evaluate a Type A or Type B Class 1 component of cylindrical shape subject to external pressure.  If the flaw is found to be unacceptable, the procedure can be used to establish a new .
			5.4.3.4 The assessment procedure in this paragraph can be used to determine the acceptability of the circumferential extent of a flaw in a cylindrical or conical shell subject to internal pressure and supplemental loads.  Note that the acceptability o...
			5.4.3.5 If the equipment is not acceptable for continued operation per the Level 2 Assessment requirements, then the following, or combinations thereof, can be considered:
		5.4.4 Level 3 Assessment
	5.5 Remaining Life Assessment
		5.5.1 Thickness Approach
			5.5.1.1 The remaining life of a component with a region of local metal loss can be estimated based upon computation of a minimum required thickness for the intended service conditions, actual thickness and region size measurements from an inspection, ...
			5.5.1.2 The rate-of-change in the size or characteristic length of a region of local metal loss can be estimated based upon inspection records.  If this information is not available, engineering judgment should be applied to determine the sensitivity ...
			5.5.1.3 The remaining life determined using the thickness-based approach can only be utilized if the region of local metal loss is characterized by a single thickness.  If a thickness profile is utilized (Level 2 assessment procedure), the remaining l...
		5.5.2 MAWP Approach
	5.6 Remediation
	5.7 In-Service Monitoring
	5.8 Documentation
		5.8.1 General
		5.8.2 Inspection Data
	5.9 Nomenclature
	5.10 References
	5.11  Tables
	5.12 Figures
Annex 5A  – Technical Basis and Validation – Assessment Of Local Metal Loss
	5A.1 Technical Basis and Validation
	5A.2 References
Part 6  – Assessment Of Pitting Corrosion
	6.1 General
		6.1.1 Assessment of Pitting Corrosion
		6.1.2 Assessment of Blister Arrays
	6.2 Applicability and Limitations of the Procedure
		6.2.1 Assessment of Four Types of Pitting Corrosion
		6.2.2 Calculation of the MAWPr and MFHr and Coincident Temperature
		6.2.3 Limitations Based on Flaw Type
		6.2.4 Limitations Based on Temperature
		6.2.5 Applicability of the Level 1 and Level 2 Assessment Procedures
			6.2.5.1 The Level 1 and 2 assessment procedures in this Part shall apply only if all of the following conditions are satisfied.
			6.2.5.2 A Level 2 Assessment shall be performed if:
		6.2.6 Applicability of the Level 3 Assessment Procedures
		6.2.7 Assessment for Active Pitting Corrosion
		6.2.8 Future Corrosion Allowance
	6.3 Data Requirements
		6.3.1 Original Equipment Design Data
		6.3.2 Maintenance and Operational History
		6.3.3 Required Data/Measurements for a FFS Assessment
			6.3.3.1 In a Level 1 Assessment, a measure of the surface damage in terms of pitted area and the maximum pit depth are used to quantify the extent of pitting corrosion.  The depth of a pit should be carefully measured because of the variety of pit typ...
			6.3.3.2 In a Level 2 Assessment, the measure of damage used to evaluate pitting is the pit-couple.  A pit-couple is composed of two pits separated by a solid ligament (see Figure 6.14).  The metal loss of each pit in a pit-couple is modeled as an equi...
			6.3.3.3 The information required to perform a Level 3 Assessment depends on the analysis method utilized.  In general, a limit load procedure using a numerical technique can be used to establish the acceptable operating or design conditions as appropr...
			6.3.3.4 The future Pitting Progression Rate (PPR) should be estimated.  This is not a straightforward procedure because pits can increase in size (depth and diameter), increase in density, and a region of local pitting may increase in size.  All pit d...
		6.3.4 Recommendation for Inspection Technique and Sizing Requirements
			6.3.4.1 Precise measurement of pitting is difficult.  Care should be taken to ensure that the correct dimensions are measured because pits often have irregular shapes as shown in Figure 6.5 or are filled with scale.  Pit gauges are used to measure pit...
			6.3.4.2 It is difficult to detect small diameter pits or to measure the depth of pits using ultrasonic methods.  Radiography may also be used to characterize the damage in pitted regions.
			6.3.4.3 If the surface is scaled, dirty or has a damaged coating, cleaning (e.g. sandblasting) may be required in order to obtain accurate pit measurements.
			6.3.4.4 Inspection techniques that characterize pitting corrosion from the opposite surface should only be used when they have sufficient resolution and coverage to ensure that significant damage cannot be overlooked.
	6.4 Assessment Techniques and Acceptance Criteria
		6.4.1 Overview
			6.4.1.1 If the depth of all of the pits is less than the specified corrosion/erosion allowance and adequate thickness is available for future pitting corrosion (see paragraph 6.5.1), no further action is required other than to record the data; otherwi...
			6.4.1.2 An overview of the assessment levels is provided in Figure 6.1.
		6.4.2 Level 1 Assessment
			6.4.2.1 The Level 1 Assessment technique utilizes standard pit charts and the maximum pit depth in the area being evaluated to estimate a Remaining Strength Factor, .  The surface damage of the pitted region is characterized by making a visual compari...
			6.4.2.2 The following assessment procedure can be used to evaluate Type A components subject to internal pressure that meet the conditions stipulated in paragraph 6.2.5.1 that are applicable to a Level 1 assessment.  For an atmospheric storage tank, t...
			6.4.2.3 If the component does not meet the Level 1 assessment requirements, then the following, or combinations thereof, can be considered:
		6.4.3 Level 2 Assessment
			6.4.3.1 The assessment procedure in paragraphs 6.4.3.2, 6.4.3.3, and 6.4.3.4 are used to determine the acceptability for the circumferential stress direction.  The assessment procedure in paragraph 6.4.3.5 is used to determine the acceptability for th...
			6.4.3.2 The following assessment procedure can be used to evaluate components with widespread or localized pitting when conditions described in paragraph 6.2.5.1 are met.  If the flaw is found to be unacceptable in the circumferential stress direction...
			6.4.3.3 Pitting Confined Within A Region Of Localized Metal Loss – If the pitting corrosion is confined within a region of localized metal loss (see Figure 6.16), then the results can be evaluated using the following methodology.  This procedure assum...
			6.4.3.4 Region Of Local Metal Loss Located In An Area Of Widespread Pitting – If a region of local metal loss (LTA) is located in an area of widespread pitting, then a combined Remaining Strength Factor can be determined using Equation (6.24) and the ...
			6.4.3.5 The assessment procedures in this paragraph should be used to determine the acceptability of the longitudinal stress direction in a cylindrical or conical shell or pipe with pitting corrosion subject to internal pressure and supplemental loads...
			6.4.3.6 Type B Class 2 Components with pitting may be evaluated using the assessment procedure in Part 4, paragraph 4.4.3.3.  For this analysis, the average measure thickness, , calculated using the following equation shall be used.
			6.4.3.7 If the component does not meet the Level 2 Assessment requirements, then the following, or combinations thereof, can be considered:
		6.4.4 Level 3 Assessment
			6.4.4.1 The stress analysis techniques discussed in Annex 2D can be utilized to assess pitting corrosion in pressure vessels, piping, and tankage.  The limit load techniques described in Annex 2D are typically recommended for this evaluation.
			6.4.4.2 If a numerical computation (e.g. finite element method) is used to evaluate pitting, two alternatives for modeling the pits may be considered.  In the first method, the pits can be modeled directly using three dimensional continuum finite elem...
			6.4.4.3 Multiple Layer Analysis – This analysis is used to account for pitting on both sides of the component (see Figure 6.3), when the pitting corrosion is not overlapping.  In this analysis,  is calculated for each pit-couple using Equations (6.14)...
	6.5 Remaining Life Assessment
		6.5.1 MAWP Approach
			6.5.1.1 The  approach (see Part 4, paragraph 4.5.2) provides a systematic way of determining the remaining life of a pressurized component with pitting.  When estimating the remaining life of pitting corrosion, a Pit Propagation Rate should be determi...
			6.5.1.2 Pits can grow in three different modes and suitable estimates for a propagation rate should be established for each mode.  In addition to these individual modes, pitting corrosion can also grow from a combination of these modes.
			6.5.1.3 If an estimate of the propagation rates cannot be made, remediation methods may be used to minimize future pitting corrosion.
		6.5.2 MAWP Procedure for Remaining Life Determination
			6.5.2.1 This approach may also be applied to tankage; however, in this case, the liquid maximum fill height, , is evaluated instead of the .
	6.6 Remediation
	6.7 In-Service Monitoring
	6.8 Documentation
		6.8.1 General
		6.8.2 Inspection Data
	6.9 Nomenclature
	6.10 References
	6.11 Tables
	6.12 Figures
Annex 6A  – Technical Basis and Validation – Assessment Of Pitting Corrosion
	6A.1 Technical Basis and Validation
	6A.2 References
Part 7  – Assessment Of Hydrogen Blisters And Hydrogen Damage Associated With HIC And SOHIC
	7.1 General
		7.1.1 Assessment Procedures for Hydrogen Blisters, HIC and SOHIC
		7.1.2 HIC Definition
		7.1.3 SOHIC Definition
		7.1.4 Hydrogen Blistering Definition
		7.1.5 HIC, SOHIC and Blistering Distinct Damage Types
	7.2 Applicability and Limitations of the Procedure
		7.2.1 HIC, SOHIC and Blistering Distinct Damage Types
		7.2.2 Calculation of the MAWPr and MFHr and Coincident Temperature
		7.2.3 Limitations Based on Temperature
		7.2.4 Applicability of the Level 1 and Level 2 Assessment Procedures
		7.2.5 Applicability of the Level 3 Assessment Procedure
	7.3 Data Requirements
		7.3.1 Original Equipment Design Data
		7.3.2 Maintenance and Operational History
		7.3.3 Required Data/Measurements for a FFS Assessment
			7.3.3.1 The required data and measurements for assessment of HIC damage are listed below:
			7.3.3.2 The required data and measurements for assessment of SOHIC damage are as follows:
			7.3.3.3 The required data and measurements for assessment of blister damage are as follows:
			7.3.3.4 The required data and measurements for laminations if Part 13 directed the user to Part 7 should be per paragraph 7.3.3.1 for laminations treated as HIC damage or paragraph 7.3.3.3 for laminations treated as blisters.
			7.3.3.5 The information in paragraph 7.3.3.1 and paragraph 7.3.3.3 should be recorded in a format similar to the ones shown in Table 7.1 for HIC damage and Table 7.2 for blister damage.  In addition, a detailed sketch should be created showing this in...
		7.3.4 Recommendations for Detection, Characterization, and Sizing
			7.3.4.1 Recommendations for Detection, Characterization, and Sizing of HIC Damage are given below:
			7.3.4.2 Recommendations for Detection, Characterization, and Sizing of SOHIC Damage are given below:
			7.3.4.3 Recommendations for Detection, Characterization, and Sizing of Blister Damage are shown below:
	7.4 Assessment Techniques and Acceptance Criteria
		7.4.1 Overview
			7.4.1.1 If the HIC or blister is located within the region of the specified corrosion/erosion allowance, the assessment procedures of this Part should still be followed.  For laminations in a component in hydrogen charging service use:
			7.4.1.2 An overview of the assessment levels for HIC damage is provided below:
			7.4.1.3 An overview of the assessment levels for SOHIC damage is provided below:
			7.4.1.4 An overview of the assessment levels for blisters is provided below:
		7.4.2 Level 1 Assessment
			7.4.2.1 HIC Assessment Procedure
			7.4.2.2 SOHIC Assessment Procedure
			7.4.2.3 Blister Assessment Procedure
			7.4.2.4 If the component does not meet the Level 1 Assessment requirements, then the following, or combinations thereof, can be considered:
		7.4.3 Level 2 Assessment
			7.4.3.1 HIC Assessment Procedure
			7.4.3.2 SOHIC Assessment Procedure
			7.4.3.3 Blister Assessment Procedure
			7.4.3.4 If the component does not meet the Level 2 Assessment requirements (see paragraph 2.4.2.2.e) then the following, or combinations thereof, can be considered:
		7.4.4 Level 3 Assessment
			7.4.4.1 HIC Assessment Procedure
			7.4.4.2 SOHIC Assessment Procedure
			7.4.4.3 Blister Assessment Procedure
	7.5 Remaining Life Assessment
		7.5.1 HIC and SOHIC Growth Rates
		7.5.2 Blister Growth
	7.6 Remediation
		7.6.1 Elimination of Hydrogen Charging
		7.6.2 Controlling Hydrogen Charging
		7.6.3 Venting of Blisters
		7.6.4 Blend Grinding
		7.6.5 Repair and Replacement of Damaged Material
		7.6.6 NACE Standard SP0296-10
	7.7 In-Service Monitoring
		7.7.1 Monitoring for Hydrogen Charging
		7.7.2 Inspection Methods for Monitoring
		7.7.3 Detection of HIC, SOHIC, or Blister Damage Growth
	7.8 Documentation
		7.8.1 General
		7.8.2 Inspection Data
		7.8.3 In-Service Monitoring
	7.9 Nomenclature
	7.10 References
	7.11  Tables
	7.12  Figures
Annex 7A  – Technical Basis and Validation – Assessment Of  Hydrogen Blisters And Hydrogen Damage Associated With HIC And SOHIC
	7A.1 Technical Basis and Validation
	7A.2 References
Part 8  – Assessment Of Weld Misalignment And Shell Distortions
	8.1 General
		8.1.1 Evaluation of Weld Misalignment and Shell Distortions
		8.1.2 ASME B&PV Code, Section VIII, Division 2
	8.2 Applicability and Limitations of the Procedure
		8.2.1 Types of Weld Misalignment and Shell Distortions
			8.2.1.1 Overview
			8.2.1.2 Weld Misalignment – Categories covered include centerline offset, angular misalignment (peaking), and a combination of centerline offset and angular misalignment of butt weld joints in flat plates, cylindrical shells and spherical shells (see ...
			8.2.1.3 Shell Distortion – Categories of shell distortion are defined as follows:
		8.2.2 Limitations Based on Flaw Type
		8.2.3 Calculation of the MAWPr and MFHr and Coincident Temperature
		8.2.4 Limitations Based on Temperature
		8.2.5 Applicability of the Level 1 and Level 2 Assessment Procedures
			8.2.5.1 Level 1 Assessment procedures are based on the criteria in the original construction code.  If these criteria are not completely defined by the original construction code and are not in the original owner-user design specification, a Level 2 o...
			8.2.5.2 The Level 2 assessment procedures in this part apply only if all of the following conditions are satisfied:
		8.2.6 Applicability of the Level 3 Assessment
	8.3 Data Requirements
		8.3.1 Original Equipment Design Data
		8.3.2 Maintenance and Operational History
		8.3.3 Required Data/Measurements for a FFS Assessment
			8.3.3.1 The information typically used for a Level 1 and Level 2 Assessment is covered in paragraphs 8.4.2 and 8.4.3, respectively.  A summary of these data is provided in Table 8.1.
			8.3.3.2 The information required to perform a Level 3 Assessment depends on the analysis method utilized.  A detailed stress analysis or limit load procedure using a numerical technique can be used to establish acceptable operating conditions.  For su...
		8.3.4 Recommendations for Inspection Technique and Sizing Requirements
			8.3.4.1 Measurement of the radial (offset) and angular (peaking) misalignment at the weld joint is required to use the assessment procedures for weld misalignment.
			8.3.4.2 Measurement of the radius and associated deviation from the mean radius at positions around the circumference are required to use the assessment procedures for circumferential out-of-roundness of cylindrical shells.
			8.3.4.3 An estimate of the local radius, , is required to use the assessment procedures for local imperfections in cylindrical shells subject to external pressure.  The local radius, , can be estimated using the guidelines shown in Figure 8.10.
			8.3.4.4 Estimates of the local bulge radii and the bulge angular extent are required to use the assessment procedures for bulges.  In addition, if the bulge is caused by local heating, hardness values and other in-situ testing should be considered to ...
	8.4 Evaluation Techniques and Acceptance Criteria
		8.4.1 Overview
		8.4.2 Level 1 Assessment
			8.4.2.1 The Level 1 assessment procedures are based on the fabrication tolerances provided in the original construction code.  Tables 8.3 through 8.7 provide an overview of these tolerances for the following construction codes.  For equipment or compo...
			8.4.2.2 If the component does not meet the Level 1 Assessment requirements, then a Level 2 or Level 3 Assessment can be conducted.
		8.4.3 Level 2 Assessment
			8.4.3.1 The Level 2 assessment procedures are computational procedures for assessment of a weld misalignment or shell distortion in a component subject to pressure and supplemental loads.  Calculation methods are provided to rerate the component if th...
			8.4.3.2 Weld Misalignment
			8.4.3.3 Out-Of-Roundness – Cylindrical Shells and Pipe Elbows
			8.4.3.4 Combined Weld Misalignment and Out-Of-Roundness in Cylindrical Shells Subject To Internal Pressure
			8.4.3.5 Out-Of-Roundness – Cylindrical Shells Subject To External Pressure (Buckling Assessment)
			8.4.3.6 Bulges
			8.4.3.7 Rerating Components
			8.4.3.8 Fatigue Analysis
			8.4.3.9 If the component does not meet the Level 2 Assessment requirements, then the following, or combinations thereof, should be considered:
		8.4.4 Level 3 Assessment
			8.4.4.1 The stress analysis techniques in Annex 2D can be used to assess the weld misalignment or shell distortion discussed in this part in pressure vessels, piping, and tankage.
			8.4.4.2 Linear stress analysis and the stress categorization techniques discussed in Annex 2D, paragraph 2D.2.2 can be used to analyze misalignment at weld joints.  In the Level 2 Assessment, the induced bending stress resulting from misalignment is c...
			8.4.4.3 The non-linear stress analysis techniques described in Annex 2D, paragraph 2D.2.4 may be utilized to analyze general shell distortions.
			8.4.4.4 If the component is subject to a compressive stress field, the non-linear stress analysis techniques described in Annex 2D, paragraph 2D.2.4 may be used for the assessment.  If geometric non-linearity is included along with material non-linear...
			8.4.4.5 If the component is operating in the creep range, a non-linear analysis that includes both material (plasticity and creep) and geometric non-linearity should be performed.  Stresses due to a localized weld misalignment or shell distortion may ...
			8.4.4.6 If the component contains a weld misalignment or shell distortion with highly localized stresses, a detailed non-linear stress analysis and assessment should be performed.  This assessment should also include an evaluation of the material toug...
	8.5 Remaining Life Assessment
		8.5.1 Categories – Metal Loss, Cyclic Loading, High Temperature Operation
		8.5.2 Requirements for a Level 3 Assessment
	8.6 Remediation
		8.6.1 Addition of Reinforcement
		8.6.2 Correction of Tolerances by Mechanical Means
	8.7 In-Service Monitoring
		8.7.1 Overview
		8.7.2 Groove-Like and Crack-Like Flaws
	8.8 Documentation
	8.9 Nomenclature
	8.10 References
	8.11  Tables
	8.12  Figures
Annex 8A  – Technical Basis And Validation – Assessment Of Weld Misalignment And Shell Distortions
	8A.1 Technical Basis and Validation
	8A.2 References
Part 9  – Assessment Of Crack-Like Flaws
	9.1 General
		9.1.1 Assessment Procedures for Crack-Like Flaws
		9.1.2 ASME B&PV Code, Section VIII, Division 2 (VIII-2)
		9.1.3 Crack-Like Flaw Definition
		9.1.4 Treatment of Volumetric Flaws as Crack-Like Flaws
		9.1.5 Use of Assessment Procedures to Evaluate Brittle Fracture
		9.1.6 Service Environment and Material Interactions with Crack-Like flaws
	9.2 Applicability and Limitations of the Procedure
		9.2.1 Overview
		9.2.2 Applicability of the Level 1 and Level 2 Assessment Procedures
		9.2.3 Applicability of the Level 3 Assessment Procedure
		9.2.4 Assessment Procedures for Notches in Groove-Like Flaws
	9.3 Data Requirements
		9.3.1 General
			9.3.1.1 The information required for a Level 1 Assessment is shown below:
			9.3.1.2 The information required to perform a Level 2 or Level 3 Assessment is covered in paragraphs 9.3.2 through 9.3.7.  The choice of input data should be conservative to compensate for uncertainties.  In a Level 3 assessment, a sensitivity analysi...
			9.3.1.3 The datasheet shown in Table 9.1 should be completed before the  assessment is started.  This ensures that all of the pertinent factors are considered, communicated, and incorporated into the assessment.  The information on this datasheet is u...
		9.3.2 Original Equipment Design Data
			9.3.2.1 An overview of the original equipment data required for an assessment is provided in Part 2, paragraph 2.3.1.
			9.3.2.2 Equipment data is required in order to compute the stress intensity factor and reference stress solution based on the geometry of the component at the crack location.
		9.3.3 Maintenance and Operating History
			9.3.3.1 An overview of the maintenance and operating history required for an assessment is provided in Part 2, paragraph 2.3.2.
			9.3.3.2 Maintenance and operational input should be provided by personnel familiar with the operational and maintenance requirements of the component containing the crack-like flaw.  This data provides a basis for determining the following:
		9.3.4 Required Data/Measurements for a FFS Assessment – Loads and Stresses
			9.3.4.1 Load Cases
			9.3.4.2 Stress Computation
			9.3.4.3 Stress Classification
		9.3.5 Required Data/Measurements for a FFS Assessment – Material Properties
			9.3.5.1 Material Yield and Tensile Strength
			9.3.5.2 Material Fracture Toughness
			9.3.5.3 Crack Growth Model
			9.3.5.4 Material Physical Constants
		9.3.6 Required Data/Measurements for a FFS Assessment – Flaw Characterization
			9.3.6.1 Overview
			9.3.6.2 Characterization of Flaw Length
			9.3.6.3 Characterization of Flaw Depth
			9.3.6.4 Characterization of Branched Cracks
			9.3.6.5 Characterization of Multiple Flaws
			9.3.6.6 Recategorization of Flaws
		9.3.7 Recommendation for Inspection Technique and Sizing Requirements
			9.3.7.1 Reliable sizing of the flaws by nondestructive examination (NDE) is important.  Therefore, the choice of the NDE method should be based on its ability to detect and size the depth and length of the flaw.
			9.3.7.2 As previously discussed in paragraph 9.3.6, the crack dimensions required as input for an  analysis are the crack depth, crack length, crack angle with the plate surface, crack location from the surface, and the spacing between the cracks if t...
			9.3.7.3 Accurate sizing of crack-like flaws depends on both the available technology and the skill of the inspector.  Parameters to be considered in the uncertainties of flaw sizing include the crack length, depth, flaw orientation, whether or not the...
			9.3.7.4 Determination of the depth, orientation and position, i.e. the location below the surface for an embedded crack, of a crack-like flaw is usually done by using ultrasonic examination techniques.  Radiographic examination techniques may also be ...
			9.3.7.5 If part of a component is inaccessible for inspection due to the component configuration, materials used, or obstruction by other flaws, and a flaw is suspected in this region because of the surrounding conditions, the possibility of the exist...
	9.4 Assessment Techniques and Acceptance Criteria
		9.4.1 Overview
			9.4.1.1 The Fitness-For-Service assessment procedure used to evaluate crack-like flaws is shown in Figure 9.10.  The three assessment levels used to evaluate crack-like flaws are summarized below.
			9.4.1.2 The assessment levels designated in this document are based on the definitions in Part 2 and are different from the assessment levels described in BS PD6493, BS 7910, and EDF Energy Nuclear Generation Limited R-6 (see Part 1, Table 1.1).
		9.4.2 Level 1 Assessment
			9.4.2.1 The Level 1 Assessment is applicable to components that satisfy the limitations in paragraph 9.2.2.1.
			9.4.2.2 The following procedure can be used to determine the acceptability of a crack-like flaw using a Level 1 Assessment.
			9.4.2.3 The Level 1 Assessment may be based on the Level 2 Assessment calculation procedure subject to the restrictions and requirements stipulated in paragraph 9.2.2.1.
			9.4.2.4 If the component does not meet the Level 1 Assessment requirements, then the following actions, or combination thereof, shall be taken:
		9.4.3 Level 2 Assessment
			9.4.3.1 The Level 2 Assessment is applicable to components and loading conditions that satisfy the conditions given in paragraph 9.2.2.1.  The assessment procedure in Level 2 provides a better estimate of the structural integrity of a component than a...
			9.4.3.2 The following procedure can be used to determine the acceptability of a crack-like flaw using a Level 2 Assessment.
			9.4.3.3 A limiting flaw size can be established using the following procedure.  Determination of the limiting flaw size may be useful in selecting an appropriate NDE technique for inspection.
			9.4.3.4 In certain cases, an acceptable flaw size may be predicted using the Level 2 Assessment procedure although smaller flaw sizes may be unacceptable.  This condition, referred to as a “non-unique solution” (see Annex 9A, reference [27]) is a resu...
			9.4.3.5 If the component does not meet the Level 2 Assessment requirements, then the following actions, or combination thereof, shall be taken:
		9.4.4 Level 3 Assessment
			9.4.4.1 The Level 3 Assessment procedure provides the best estimate of the structural integrity of a component with a crack-like flaw.  In addition, this assessment level is required if subcritical crack growth is possible during future operation.  Fi...
			9.4.4.2 For each Method, a sensitivity analysis, partial safety factors or a probabilistic analysis shall be used in the assessment to evaluate uncertainties in the input parameters.
			9.4.4.3 It is the responsibility of the Engineer to meet all limitations and requirements imposed by the selected method.  In addition, the Engineer must ensure that the method used including all assumptions, analysis parameters, results and conclusio...
	9.5 Remaining Life Assessment
		9.5.1 Subcritical Crack Growth
			9.5.1.1 Overview
			9.5.1.2 Evaluation and Analysis Procedures for Components with Growing Cracks
			9.5.1.3 Alternative Analysis Procedure for Components with Growing Fatigue Cracks
		9.5.2 Leak-Before-Break Analysis
			9.5.2.1 Overview
			9.5.2.2 Limitations of LBB
			9.5.2.3 LBB Procedure
			9.5.2.4 Flaw Dimensions for LBB
			9.5.2.5 Leak Area Calculations for LBB Analysis
			9.5.2.6 Leak Rate Calculations for Through-Wall Cracks
			9.5.2.7 Analysis of Critical Leak Length (CLL) of Through-Wall Cracks
	9.6 Remediation
		9.6.1 Objectives of Remediation
		9.6.2 Remediation Methods
			9.6.2.1 Remediation Method 1 – Removal or repair of the crack.  The crack may be removed by blend grinding.  The resulting groove is then repaired using a technique to restore the full thickness of material and the weld repair is subject to PWHT in ac...
			9.6.2.2 Remediation Method 2 – Use of a crack arresting detail or device.  For components that are not a pressure boundary, the simplest form of this method is to drill holes at the end of an existing crack to effectively reduce the crack driving forc...
			9.6.2.3 Remediation Method 3 – Performing physical changes to the process stream (see Part 4, paragraph 4.6.3).  This method can be used to reduce the crack driving force (reduction in pressure) or to provide an increase in the material toughness at t...
			9.6.2.4 Remediation Method 4 – Application of solid barrier linings or coatings to keep the environment isolated from the metal (see Part 4, paragraph 4.6.4).  In this method, the flaw is isolated from the process environment to minimize the potential...
			9.6.2.5 Remediation Method 5 – Injection of water and/or chemicals on a continuous basis to modify the environment or the surface of the metal (see Part 4, paragraph 4.6.5).  In this method, the process environment is controlled to minimize the potent...
			9.6.2.6 Remediation Method 6 – Application of weld overlay (see Part 4, paragraph 4.6.6).  In this method, weld overlay is applied to the component surface opposite to the surface containing the cracks to introduce a compressive residual stress field ...
			9.6.2.7 Remediation Method 7 – Use of leak monitoring and leak-sealing devices.
	9.7 In-Service Monitoring
		9.7.1 Monitoring of Subcritical Crack Growth
		9.7.2 Validation of Monitoring Method
	9.8 Documentation
		9.8.1 General
		9.8.2 Assessment Procedure
		9.8.3 Remediation Methods
		9.8.4 In-Service Monitoring
	9.9 Nomenclature
	9.10 References
	9.11  Tables
	9.12 Figures
Annex 9A  – Technical Basis And Validation – Assessment Of Crack-Like Flaws
	9A.1 Technical Basis and Validation
	9A.2 References
Annex 9B  – Compendium Of Stress Intensity Factor Solutions
	9B.1 General
		9B.1.1 Overview
		9B.1.2 Stress Intensity Factor Solutions
		9B.1.3 Stress Intensity Factor Solutions – Approximation For Shells
		9B.1.4 Stress Intensity Factor Identifier
		9B.1.5 Alternate Sources for Stress Intensity Factor Solutions
	9B.2 Stress Analysis
		9B.2.1 Overview
			9B.2.1.1 A stress analysis using handbook or numerical techniques is required to compute the state of stress at the location of a crack.  The stress distribution to be utilized in determining the stress intensity factor is based on the component of st...
			9B.2.1.2 The stress distribution normal to the crack face should be determined for the primary, secondary, and residual stress loading conditions based on the service requirements that the uncracked component geometry is subjected to.  If the componen...
		9B.2.2 Stress Distributions
			9B.2.2.1 Overview – The stress intensity factor solutions in this Annex are formulated in terms of the coefficients of a linear stress distribution (membrane and bending) or fourth order polynomial stress distribution, or in terms of a general stress ...
			9B.2.2.2 General Stress Distribution – A general stress distribution through the wall thickness can be obtained from a two or three-dimensional elasticity solution (e.g. Lame solutions for a thick wall cylinder and sphere) or it can be determined usin...
			9B.2.2.3 Fourth Order Polynomial Stress Distribution – The fourth order polynomial stress distribution can be obtained by curve-fitting the general stress distribution.  This distribution is utilized to obtain a more accurate representation of the str...
			9B.2.2.4 Fourth Order Polynomial Stress Distribution With Net Section Bending Stress – This distribution is used to represent a through-wall fourth order polynomial stress and a net section or global bending stress applied to a circumferential crack i...
			9B.2.2.5 Membrane and Through-Wall Bending – The membrane and bending stress distributions are linear through the wall thickness and represent a common subset of the general stress distribution.  These distributions occur in thin plate and shell struc...
		9B.2.3 Surface Correction Factors
			9B.2.3.1 Surface correction or bulging factors are used to quantify the local increase in the state of stress at the location of a crack in a shell that occurs because of local bulging.  The magnified state of stress is then used together with a refer...
			9B.2.3.2 The surface correction factors for through-wall cracks in cylindrical and spherical shells subject to membrane stress loading are defined in Annex 9C, paragraph 9C.2.3.2.  The surface correction factors for surface cracks can be approximated ...
	9B.3 Stress Intensity Factor Solutions for Plates
		9B.3.1 KPTC Plate – Through-Wall Crack, Through-Wall Membrane and Bending Stress (KPTC)
			9B.3.1.1 The Mode I Stress Intensity Factor (References [1] and [35])
			9B.3.1.2 Notes:
		9B.3.2 Plate – Surface Crack, Infinite Length, Through-Wall Fourth Order Polynomial Stress Distribution (KPSCL1)
			9B.3.2.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.3.2.2 Notes:
		9B.3.3 Plate – Surface Crack, Infinite Length, Through-Wall Arbitrary Stress Distribution (KPSCL2)
			9B.3.3.1 The Mode I Stress Intensity Factor (Reference [3])
			9B.3.3.2 Notes: see paragraph 9B.3.2.2.
		9B.3.4 Plate – Surface Crack, Semi-Elliptical Shape, Through-wall Membrane and Bending Stress (KPSCE1)
			9B.3.4.1 The Mode I Stress Intensity Factor (Reference [1])
			9B.3.4.2 Notes:
		9B.3.5 Plate – Surface Cracks, Semi-Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (KPSCE2)
			9B.3.5.1 The Mode I Stress Intensity Factor (Reference [3])
			9B.3.5.2 Notes:
		9B.3.6 Plate – Surface Crack, Semi-Elliptical Shape, Through-Wall Arbitrary Stress Distribution (KPSCE3)
			9B.3.6.1 The Mode I Stress Intensity Factor (Reference [6])
			9B.3.6.2 Notes:
		9B.3.7 Plate – Embedded Crack, Infinite Length, Through-Wall Fourth Order Polynomial Stress Distribution (KPECL)
			9B.3.7.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.3.7.2 Notes:
		9B.3.8 Plate – Embedded Crack, Elliptical Shape, Through-Wall Membrane and Bending Stress (KPECE1)
			9B.3.8.1 The Mode I Stress Intensity Factor (Reference [4])
			9B.3.8.2 Notes:
		9B.3.9 Plate – Embedded Crack, Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (KPECE2)
			9B.3.9.1 Mode I Stress Intensity Factor (Reference [40])
			9B.3.9.2 Notes:
	9B.4 Stress Intensity Factor Solutions for Plates with Holes
		9B.4.1 Plate with Hole – Through-Wall Single Edge Crack, Through-Wall Membrane and Bending Stress (KPHTC1)
			9B.4.1.1 The Mode I Stress Intensity Factor (References [2] and [12])
			9B.4.1.2 Notes:
		9B.4.2 Plate with Hole – Through-Wall Double Edge Crack, Through-Wall Membrane and Bending Stress (KPHTC2)
			9B.4.2.1 The Mode I Stress Intensity Factor (References [2] and [12])
			9B.4.2.2 Notes:
		9B.4.3 Plate with Hole – Surface Crack In Hole, Semi-Elliptical Shape, Through-Wall Membrane Stress (KPHSC1)
			9B.4.3.1 The Mode I Stress Intensity Factor (Reference [1])
			9B.4.3.2 Notes:
		9B.4.4 Plate with Hole, Corner Crack, Semi-Elliptical Shape, Through-Wall Membrane and Bending Stress (KPHSC2)
			9B.4.4.1 The Mode I Stress Intensity Factor (Reference [1])
			9B.4.4.2 Notes:
	9B.5 Stress Intensity Factor Solutions for Cylinders
		9B.5.1 Cylinder – Through-Wall Crack, Longitudinal Direction, Through-Wall Membrane and Bending Stress (KCTCL)
			9B.5.1.1 The Mode I Stress Intensity Factor (References [11] and [16])
			9B.5.1.2 Notes:
		9B.5.2 Cylinder – Through-Wall Crack, Circumferential Direction, Through-Wall Membrane and Bending Stress (KCTCC1)
			9B.5.2.1 The Mode I Stress Intensity Factor (References [11] and [16])
			9B.5.2.2 Notes:
		9B.5.3 Cylinder – Through-Wall Crack, Circumferential Direction, Pressure with Net Section Axial Force and Bending Moment (KCTCC2)
			9B.5.3.1 The Mode I Stress Intensity Factor (Reference [16])
			9B.5.3.2 Notes:
		9B.5.4 Cylinder – Surface Crack, Longitudinal Direction – Infinite Length, Internal Pressure (KCSCLL1)
			9B.5.4.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.5.4.2 Notes:
		9B.5.5 Cylinder – Surface Crack, Longitudinal Direction – Infinite Length, Through-Wall Fourth Order Polynomial Stress Distribution (KCSCLL2)
			9B.5.5.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.5.5.2 Notes:
		9B.5.6 Cylinder – Surface Crack, Longitudinal Direction – Infinite Length, Through-Wall Arbitrary Stress Distribution (KCSCLL3)
			9B.5.6.1 The Mode I Stress Intensity Factor
			9B.5.6.2 Notes: see paragraph 9B.5.4.2.
		9B.5.7 Cylinder – Surface Crack, Circumferential Direction – 360 Degrees, Pressure With A Net Section Axial Force and Bending Moment (KCSCCL1)
			9B.5.7.1 The Mode I Stress Intensity Factor
			9B.5.7.2 Notes:
		9B.5.8 Cylinder – Surface Crack, Circumferential Direction – 360 Degrees, Through-Wall Fourth Order Polynomial Stress Distribution (KCSCCL2)
			9B.5.8.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.5.8.2 Notes:
		9B.5.9 Cylinder – Surface Crack, Circumferential Direction – 360 Degrees, Through-Wall Arbitrary Stress Distribution (KCSCCL3)
			9B.5.9.1 The Mode I Stress Intensity Factor
			9B.5.9.2 Notes: see paragraph 9B.5.7.2.
		9B.5.10 Cylinder – Surface Crack, Longitudinal Direction – Semi-Elliptical Shape, Internal Pressure (KCSCLE1)
			9B.5.10.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.5.10.2 Notes:
		9B.5.11 Cylinder – Surface Crack, Longitudinal Direction – Semi-Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (KCSCLE2)
			9B.5.11.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.5.11.2 Notes:
		9B.5.12 Cylinder – Surface Crack, Longitudinal Direction – Semi-Elliptical Shape, Through-Wall Arbitrary Stress Distribution (KCSCLE3)
			9B.5.12.1 The Mode I Stress Intensity Factor
			9B.5.12.2 Notes: see paragraph 9B.5.10.2.
		9B.5.13 Cylinder – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Internal Pressure and Net-Section Axial Force (KCSCCE1)
			9B.5.13.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.5.13.2 Notes:
		9B.5.14 Cylinder – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution with a Net Section Bending Stress (KCSCCE2)
			9B.5.14.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.5.14.2 Notes:
		9B.5.15 Cylinder – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Through-Wall Arbitrary Stress Distribution (KCSCCE3)
			9B.5.15.1 The Mode I Stress Intensity Factor
			9B.5.15.2 Notes: see paragraph 9B.5.13.2.
		9B.5.16 Cylinder – Embedded Crack, Longitudinal Direction – Infinite Length, Through-Wall Fourth Order Polynomial Stress Distribution (KCECLL)
			9B.5.16.1 The Mode I Stress Intensity Factor solution in paragraph 9B.3.7 can be used
			9B.5.16.2 Notes:
		9B.5.17 Cylinder – Embedded Crack, Circumferential Direction – 360 Degrees, Through-Wall Fourth Order Polynomial Stress Distribution (KCECCL)
			9B.5.17.1 The Mode I Stress Intensity Factor solution in paragraph 9B.3.7 can be used.
			9B.5.17.2 Notes:
		9B.5.18 Cylinder – Embedded Crack, Longitudinal Direction – Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (KCECLE)
			9B.5.18.1 The Mode I Stress Intensity Factor solution in paragraph 9B.3.9 can be used.
			9B.5.18.2 Notes:
		9B.5.19 Cylinder – Embedded Crack, Circumferential Direction – Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (KCECCE)
			9B.5.19.1 The Mode I Stress Intensity Factor solution in paragraph 9B.3.9 can be used.
			9B.5.19.2 Notes:
	9B.6 Stress Intensity Factor Solutions for Spheres
		9B.6.1 Sphere – Through-Wall Crack, Through-Wall Membrane and Bending Stress (KSTC)
			9B.6.1.1 The Mode I Stress Intensity Factor (References [10] and [11])
			9B.6.1.2 Notes:
		9B.6.2 Sphere – Surface Crack, Circumferential Direction – 360 Degrees, Internal Pressure (KSSCCL1)
			9B.6.2.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.6.2.2 Notes:
		9B.6.3 Sphere – Surface Crack, Circumferential Direction – 360 Degrees, Through-Wall Fourth Order Polynomial Stress Distribution (KSSCCL2)
			9B.6.3.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.6.3.2 Notes:
		9B.6.4 Sphere – Surface Crack, Circumferential Direction – 360 Degrees, Through-Wall Arbitrary Stress Distribution (KSSCCL3)
			9B.6.4.1 The Mode I Stress Intensity Factor (Reference [3])
			9B.6.4.2 Notes: see paragraph 9B.6.2.2.
		9B.6.5 Sphere – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Internal Pressure (KSSCCE1)
			9B.6.5.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.6.5.2 Notes:
		9B.6.6 Sphere – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (KSSCCE2)
			9B.6.6.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.6.6.2 Notes:
		9B.6.7 Sphere – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Through-Wall Arbitrary Stress Distribution (KSSCCE3)
			9B.6.7.1 The Mode I Stress Intensity Factor (Reference [3])
			9B.6.7.2 Notes: see paragraph 9B.6.5.2.
		9B.6.8 Sphere – Embedded Crack, Circumferential Direction – 360 Degrees, Through-Wall Fourth Order Polynomial Stress Distribution (KSECCL)
			9B.6.8.1 The Mode I Stress Intensity Factor solution in paragraph 9B.3.7 can be used.
			9B.6.8.2 Notes:
		9B.6.9 Sphere – Embedded Crack, Circumferential Direction – Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (KSECCE)
			9B.6.9.1 The Mode I Stress Intensity Factor solution in paragraph 9B.3.9 can be used.
			9B.6.9.2 Notes:
	9B.7 Stress Intensity Factor Solutions for Elbows and Pipe Bends
	9B.8 Stress Intensity Factor Solutions for Nozzles and Piping Tees
		9B.8.1 Nozzle – Corner Crack, Radial Direction, Quarter-Circular Shape, Membrane Stress at the Corner (KNCC1)
			9B.8.1.1 The Mode I Stress Intensity Factor (References [36] and [37])
			9B.8.1.2 Notes:
		9B.8.2 Nozzle – Corner Crack, Radial Direction, Quarter-Circular Shape, Cubic Polynomial Stress at the Corner (KNCC)
			9B.8.2.1 The Mode I Stress Intensity Factor (Reference [40])
			9B.8.2.2 Notes:
		9B.8.3 Surface Cracks At Nozzles – General Solution
	9B.9 Stress Intensity Factor Solutions For Ring-Stiffened Cylinders
		9B.9.1 Ring-Stiffened Cylinder – Surface Crack at the Toe of One Fillet Weld, Circumferential Direction – 360 Degrees, Pressure Loading (KRCSCCL1)
			9B.9.1.1 The Mode I Stress Intensity Factor (Reference [29])
			9B.9.1.2 Notes:
		9B.9.2 Ring-Stiffened Cylinder – Surface Crack at the Toe of Both Fillet Welds, Circumferential Direction – 360 Degrees, Pressure Loading (KRCSCCL2)
			9B.9.2.1 The Mode I Stress Intensity Factor (Reference [29])
			9B.9.2.2 Notes:
	9B.10 Stress Intensity Factor Solutions for Sleeve Reinforced Cylinders
	9B.11 Stress Intensity Factor Solutions for Round Bars and Bolts
		9B.11.1 Round Bar, Surface Crack – 360 Degrees, Through-Wall Membrane and Bending Stress (KBSCL)
			9B.11.1.1 The Mode I Stress Intensity Factor (References [12] and [18])
			9B.11.1.2 Notes:
		9B.11.2 Round Bar – Surface Crack, Straight Front, Through-Wall Membrane and Bending Stress (KBSCS)
			9B.11.2.1 The Mode I Stress Intensity Factor (Reference [19])
			9B.11.2.2 Notes:
		9B.11.3 Round Bar, Surface Crack, Semi-Circular, Through-Wall Membrane and Bending Stress (KBSCC)
			9B.11.3.1 The Mode I Stress Intensity Factor (Reference [12])
			9B.11.3.2 Notes:
		9B.11.4 Bolt, Surface Crack, Semi-Circular or Straight Front Shape, Membrane and Bending Stress (KBSC)
			9B.11.4.1 The Mode I Stress Intensity Factor (Reference [17])
			9B.11.4.2 Notes:
	9B.12 Stress Intensity Factor Solutions for Cracks at Fillet Welds
		9B.12.1 Cracks at Fillet Welds – Surface Crack at a Tee Joint, Semi-Elliptical Shape, Through-Wall Membrane and Bending Stress (KFWSCE1)
			9B.12.1.1 The Mode I Stress Intensity Factor (Reference [30])
			9B.12.1.2 Notes:
		9B.12.2 Cracks at Fillet Welds In Tee Junctions– General Solution
	9B.13 Stress Intensity Factor Solutions Cracks in Clad Plates and Shells
	9B.14 The Weight Function Method for Surface Cracks
	9B.15 Nomenclature
	9B.16 Tables
	9B.17 Figures
Annex 9C  – Compendium Of Reference Stress Solutions For Crack-Like Flaws
	9C.1 General
		9C.1.1 Overview
		9C.1.2 ASME B&PV Code, Section VIII, Division 2 (VIII-2)
		9C.1.3 Reference Stress Solutions
		9C.1.4 Reference Stress Solutions – Approximations for Shells
		9C.1.5 Reference Stress Solutions Identifier
		9C.1.6 Reference Stress Solutions Not Included in the Compendium
	9C.2 Stress Analysis
		9C.2.1 Overview
			9C.2.1.1 A stress analysis using handbook or numerical techniques is required to compute the state of stress at the location of a crack.  The stress distribution to be utilized in determining the stress intensity factor is based on the component of st...
			9C.2.1.2 The stress distribution normal to the crack face resulting from primary loads should be determined based on service loading conditions and the uncracked component geometry.  If the component is subject to different operating conditions, the s...
			9C.2.1.3 In this Annex, the variable  is used in place of  to signify that the stress distributions used to determine the reference stress and the  ratio for the assessment of a crack-like flaw using the FAD (see Part 9) are categorized as primary str...
		9C.2.2 Stress Distributions
			9C.2.2.1 Overview
			9C.2.2.2 General Stress Distribution
			9C.2.2.3 Fourth Order Polynomial Stress Distribution
			9C.2.2.4 Fourth Order Polynomial Stress Distribution with Net Section Bending Stress
			9C.2.2.5 Membrane and Through-Wall Bending Stress Distribution
		9C.2.3 Surface Correction Factor for Shells
			9C.2.3.1 Overview
			9C.2.3.2 Surface Correction Factors for Through-wall Cracks
			9C.2.3.3 Surface Correction Factors for Surface Cracks
		9C.2.4 Load Ratio and Reference Stress
			9C.2.4.1 Load Ratio
			9C.2.4.2 Reference Stress Solutions
		9C.2.5 Plastic Collapse in the Assessment of Crack-Like Flaws
			9C.2.5.1 The position of an assessment point  on the FAD represents a particular combination of flaw size, stresses and material properties.  This point can be used to demonstrate whether the flaw is acceptable and an associated in-service margin can ...
			9C.2.5.2 The value of  depends on the type of plastic collapse load solution utilized in the assessment.
			9C.2.5.3 The reference stress solutions in this Annex are based on the assessment of a single flaw.  Multiple flaws which interact should be recategorized according to Part 9.  However, multiple flaws that do not interact according to Part 9 may still...
			9C.2.5.4 It is recommended that a gross collapse assessment be performed to ensure that the applied stresses derived for local conditions do not cause failure of the structure in other regions.
	9C.3 Reference Stress Solutions for Plates
		9C.3.1 Plate – Through-Wall Crack, Through-Wall Membrane and Bending Stress (RPTC)
			9C.3.1.1 The Reference Stress is (Reference [3]):
			9C.3.1.2 Notes:
		9C.3.2 Plate – Surface Crack, Infinite Length, Through-Wall Fourth Order Polynomial Stress Distribution (RPSCL1)
			9C.3.2.1 The Reference Stress is given by Equation  with the following definition of :
			9C.3.2.2 Notes:
		9C.3.3 Plate – Surface Crack, Infinite Length, Through-wall Arbitrary Stress Distribution (RPSCL2)
			9C.3.3.1 Reference Stress in paragraph 9C.3.2 can be used.
			9C.3.3.2 Notes: see paragraph 9C.3.2.2.
		9C.3.4 Plate – Surface Crack, Semi-Elliptical Shape, Through-wall Membrane and Bending Stress (RPSCE1)
			9C.3.4.1 The Reference Stress is (References [3] and [18]):
			9C.3.4.2 Notes:
		9C.3.5 Plate – Surface Cracks, Semi-Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (RPSCE2)
			9C.3.5.1 The Reference Stress in paragraph 9C.3.4 can be used.
			9C.3.5.2 Notes: see paragraph 9C.3.4.2.
		9C.3.6 Plate – Surface Crack, Semi-Elliptical Shape, Through-wall Arbitrary Stress Distribution (RPSCE3)
			9C.3.6.1 The Reference Stress in paragraph 9C.3.4 can be used.
			9C.3.6.2 Notes: see paragraph 9C.3.4.2.
		9C.3.7 Plate – Embedded Crack, Infinite Length, Through-Wall Fourth Order Polynomial Stress Distribution (RPECL)
			9C.3.7.1 The Reference Stress is (Reference [3]):
			9C.3.7.2 Notes:
		9C.3.8 Plate – Embedded Crack, Elliptical Shape, Through-Wall Membrane and Bending Stress (RPECE1)
			9C.3.8.1 The Reference Stress is given by Equation (9C.35) with following definitions of  and :
			9C.3.8.2 Notes:
		9C.3.9 Plate – Embedded Crack, Elliptical Shape, Through-Wall Fourth-Order Polynomial Stress Distribution (RPECE2)
			9C.3.9.1 The Reference Stress in paragraph 9C.3.8.1 can be used.
			9C.3.9.2 Notes:
	9C.4 Reference Stress Solutions For Plates with Holes
		9C.4.1 Plate With Hole – Through-Wall Single Edge Crack, Through-Wall Membrane and Bending Stress (RPHTC1)
			9C.4.1.1 The Reference Stress is given by Equation (9C.27) with the following definition of :
			9C.4.1.2 Notes:
		9C.4.2 Plate With Hole – Through-Wall Double Edge Crack, Through-Wall Membrane and Bending Stress (RPHTC2)
			9C.4.2.1 The Reference Stress is given by Equation (9C.27) with the following definition of :
			9C.4.2.2 Notes:
		9C.4.3 Plate With Hole – Surface Crack, Semi-Elliptical Shape, Through-Wall Membrane Stress (RPHSC1)
			9C.4.3.1 The Reference Stress is:
			9C.4.3.2 Notes:
		9C.4.4 Plate With Hole, Corner Crack, Semi-Elliptical Shape, Through-Wall Membrane and Bending Stress (RPHSC2)
			9C.4.4.1 The Reference Stress is given by Equation (9C.27) with the following definition of :
			9C.4.4.2 Notes:
	9C.5 Reference Stress Solutions For Cylinders
		9C.5.1 Cylinder – Through-Wall Crack, Longitudinal Direction, Through-Wall Membrane and Bending Stress (RCTCL)
			9C.5.1.1 The Reference Stress is (References [1] and [3])
			9C.5.1.2 Notes:
		9C.5.2 Cylinder – Through-Wall Crack, Circumferential Direction, Through-Wall Membrane and Bending Stress (RCTCC1)
			9C.5.2.1 The Reference Stress is (Reference [2]):
			9C.5.2.2 Notes:
		9C.5.3 Cylinder – Through-Wall Crack, Circumferential Direction, Pressure with a Net Section Axial Force and Bending Moment (RCTCC2)
			9C.5.3.1 The Reference Stress is (Reference [4]):
			9C.5.3.2 Notes:
		9C.5.4 Cylinder – Surface Crack, Longitudinal Direction – Infinite Length, Internal Pressure (RCSCLL1)
			9C.5.4.1 The Reference Stress (References [1], [3]):
			9C.5.4.2 Notes:
		9C.5.5 Cylinder – Surface Crack, Longitudinal Direction – Infinite Length, Through-Wall Fourth Order Polynomial Stress Distribution (RCSCLL2)
			9C.5.5.1 The Reference Stress in paragraph 9C.5.4 can be used.
			9C.5.5.2 Notes: see paragraph 9C.5.4.2.
		9C.5.6 Cylinder – Surface Crack, Longitudinal Direction – Infinite Length, Through-wall Arbitrary Stress Distribution (RCSCLL3)
			9C.5.6.1 The Reference Stress in paragraph 9C.5.4 can be used.
			9C.5.6.2 Notes: see paragraph 9C.5.4.2.
		9C.5.7 Cylinder – Surface Crack, Circumferential Direction – 360 Degrees, Pressure with a Net Section Axial Force And Bending Moment (RCSCCL1)
			9C.5.7.1 The Reference Stress is (Reference [5]):
			9C.5.7.2 Notes:
		9C.5.8 Cylinder – Surface Crack, Circumferential Direction – 360 Degrees, Through-Wall Fourth Order Polynomial Stress Distribution (RCSCCL2)
			9C.5.8.1 The Reference Stress is (Reference [2]):
			9C.5.8.2 Notes:
		9C.5.9 Cylinder – Surface Crack, Circumferential Direction – 360 Degrees, Through-wall Arbitrary Stress Distribution (RCSCCL3)
			9C.5.9.1 The Reference Stress in paragraph 9C.5.8 can be used.
			9C.5.9.2 Notes: see paragraph 9C.5.8.2.
		9C.5.10 Cylinder – Surface Crack, Longitudinal Direction – Semi-Elliptical Shape, Internal Pressure (RCSCLE1)
			9C.5.10.1 The Reference Stress is (References [3] and [6]):
			9C.5.10.2 Notes:
		9C.5.11 Cylinder – Surface Crack, Longitudinal Direction – Semi-Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (RCSCLE2)
			9C.5.11.1 The Reference Stress in paragraph 9C.5.10 can be used.
			9C.5.11.2 Notes: see paragraph. 9C.5.10.2.
		9C.5.12 Cylinder – Surface Crack, Longitudinal Direction – Semi-Elliptical Shape, Through-wall Arbitrary Stress Distribution (RCSCLE3)
			9C.5.12.1 The Reference Stress in paragraph 9C.5.10 can be used.
			9C.5.12.2 Notes: see paragraph 9C.5.10.2.
		9C.5.13 Cylinder – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Internal Pressure and Net-Section Axial Force (RCSCCE1)
			9C.5.13.1 The Reference Stress is (Reference [2]):
			9C.5.13.2 Notes:
		9C.5.14 Cylinder – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution with a Net Section Bending Stress (RCSCCE2)
			9C.5.14.1 The Reference Stress is (Reference [2]):
			9C.5.14.2 Notes:
		9C.5.15 Cylinder – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Through-wall Arbitrary Stress Distribution (RCSCCE3)
			9C.5.15.1 The Reference Stress in paragraph 9C.5.13.1 can be used.
			9C.5.15.2 Notes:
		9C.5.16 Cylinder – Embedded Crack, Longitudinal Direction – Infinite Length, Through-Wall Fourth Order Polynomial Stress Distribution (RCECLL)
			9C.5.16.1 The Reference Stress in paragraph 9C.3.7.1 can be used.
			9C.5.16.2 Notes:
		9C.5.17 Cylinder – Embedded Crack, Circumferential Direction – 360 Degrees, Through-Wall Fourth Order Polynomial Stress Distribution (RCECCL)
			9C.5.17.1 The Reference Stress in paragraph 9C.3.7.1 can be used.
			9C.5.17.2 Notes:
		9C.5.18 Cylinder – Embedded Crack, Longitudinal Direction – Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (RCECLE)
			9C.5.18.1 The Reference Stress is given by Equation (9C.35) with the following definitions for  and :
			9C.5.18.2 Notes:
		9C.5.19 Cylinder – Embedded Crack, Circumferential Direction – Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (RCECCE)
			9C.5.19.1 The Reference Stress in paragraph 9C.5.18.1 can be used.
			9C.5.19.2 Notes:
	9C.6 Reference Stress Solutions for Spheres
		9C.6.1 Sphere – Through-Wall Crack, Through-Wall Membrane and Bending Stress (RSTC)
			9C.6.1.1 The Reference Stress solution in paragraph 9C.5.1.1 can be used.
			9C.6.1.2 Notes:
		9C.6.2 Sphere – Surface Crack, Circumferential Direction – 360 Degrees, Internal Pressure (RSSCCL1)
			9C.6.2.1 The Reference Stress in paragraph 9C.5.4.1 can be used.
			9C.6.2.2 Notes:
		9C.6.3 Sphere – Surface Crack, Circumferential Direction – 360 Degrees, Through-Wall Fourth Order Polynomial Stress Distribution (RSSCCL2)
			9C.6.3.1 The Reference Stress in paragraph 9C.5.4.1 can be used.
			9C.6.3.2 Notes: see paragraph 9C.6.2.2.
		9C.6.4 Sphere – Surface Crack, Circumferential Direction – 360 Degrees, Through-wall Arbitrary Fourth Order Polynomial Stress Distribution (RSSCCL3)
			9C.6.4.1 The Reference Stress in paragraph 9C.5.4.1 can be used.
			9C.6.4.2 Notes: see paragraph 9C.6.2.2.
		9C.6.5 Sphere – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Internal Pressure (RSSCCE1)
			9C.6.5.1 The Reference Stress in paragraph 9C.5.10.1 can be used.
			9C.6.5.2 Notes:
		9C.6.6 Sphere – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (RSSCCE2)
			9C.6.6.1 The Reference Stress in paragraph 9C.5.10.1 can be used.
			9C.6.6.2 Notes: see paragraph 9C.6.5.2.
		9C.6.7 Sphere – Surface Crack, Circumferential Direction – Semi-Elliptical Shape, Through-wall Arbitrary Stress Distribution (RSSCCE3)
			9C.6.7.1 The Reference Stress in paragraph 9C.5.10.1 can be used.
			9C.6.7.2 Notes: see paragraph 9C.6.5.2.
		9C.6.8 Sphere – Embedded Crack, Circumferential Direction – 360 Degrees, Through-Wall Fourth Order Polynomial Stress Distribution (RSECCL)
			9C.6.8.1 The Reference Stress in paragraph 9C.3.7.1 can be used.
			9C.6.8.2 Notes:
		9C.6.9 Sphere – Embedded Crack, Circumferential Direction – Elliptical Shape, Through-Wall Fourth Order Polynomial Stress Distribution (RSECCE)
			9C.6.9.1 The Reference Stress in paragraph 9C.3.8.1 can be used.
			9C.6.9.2 Notes:
	9C.7 Reference Stress Solutions for Elbows And Pipe Bends
	9C.8 Reference Stress Solutions for Nozzles and Piping Tees
		9C.8.1 Nozzle – Corner Crack, Radial Direction, Quarter-Circular Shape, Membrane Stress at the Corner (RNCC1)
			9C.8.1.1 The Reference Stress is (Reference [2]):
			9C.8.1.2 Notes:
		9C.8.2 Nozzle – Corner Crack, Radial Direction, Quarter-Circular Shape, Cubic Polynomial Stress Distribution (RNCC2)
			9C.8.2.1 The Reference Stress is computed using equations in paragraph 9C.8.1.1 with an equivalent membrane stress.
			9C.8.2.2 Notes:
		9C.8.3 Surface Cracks At Nozzles – General Solution
	9C.9 Reference Stress Solutions for Ring-Stiffened Cylinders
		9C.9.1 Ring-Stiffened Cylinder – Internal Ring, Surface Crack at the Toe of One Fillet Weld, Circumferential Direction – 360 Degrees, Pressure Loading (RRCSCCL1)
			9C.9.1.1 The Reference Stress in paragraph 9C.5.8.1 can be used with an equivalent membrane and bending stress.
			9C.9.1.2 Notes:
		9C.9.2 Ring-Stiffened Cylinder – Internal Ring, Surface Crack at the Toe of Both Fillet Welds, Circumferential Direction – 360 Degrees, Pressure Loading (RRCSCCL2)
			9C.9.2.1 The Reference Stress in paragraph 9C.5.8.1 can be used with an equivalent membrane and bending stress.
			9C.9.2.2 Notes: see paragraph 9C.9.1.2.
	9C.10 Reference Stress Solutions for Sleeve Reinforced Cylinders
	9C.11 Reference Stress Solutions for Round Bars and Bolts
		9C.11.1 Round Bar, Surface Crack – 360 Degrees, Membrane and Bending Stress (RBSCL)
			9C.11.1.1 The Reference Stress is:
			9C.11.1.2 Notes:
		9C.11.2 Round Bar – Surface Crack, Straight Front, Membrane and Bending Stress (RBSCS)
			9C.11.2.1 The Reference Stress is (Reference [6]):
			9C.11.2.2 Notes:
		9C.11.3 Round Bar – Surface Crack, Semi-Circular, Membrane and Bending Stress (RBSCC)
			9C.11.3.1 The Reference Stress in paragraph 9C.11.2.1 can be used.
			9C.11.3.2 Notes:
		9C.11.4 Bolt, Surface Crack, Semi-Circular or Straight Front Shape, Membrane and Bending Stress (RBSC)
			9C.11.4.1 The Reference Stress in paragraph 9C.11.2.1 can be used by replacing  with .
			9C.11.4.2 Notes:
	9C.12 Reference Stress Solutions for Cracks at Fillet Welds
		9C.12.1 Cracks at Fillet Welds – Surface Crack at a Tee Joint, Semi-Elliptical Shape, Through-Wall Membrane and Bending Stress (RFWSCE1)
			9C.12.1.1 The Reference Stress in paragraph 9C.3.4.1 can be used with an equivalent membrane and bending stress.
			9C.12.1.2 Notes:
			9C.12.1.3 Cracks at Fillet Welds of Tee Junctions In Pressurized Components – General Solution
	9C.13 Reference Stress Solutions for Cracks in Clad Plates and Shells
	9C.14 Nomenclature
	9C.15 References
	9C.16  Figures
Annex 9D – Residual Stresses in a Fitness-For-Service Evaluation
	9D.1 General
		9D.1.1 Scope
		9D.1.2 Crack Driving Force Associated with Residual Stress
	9D.2 Applicability and Limitations
		9D.2.1 Residual Stress Solutions for In-Service and New Welded Joints
		9D.2.2 Technical Basis
		9D.2.3 Applicable Materials
		9D.2.4 Weld Joint Geometry
		9D.2.5 Residual Stress Distributions
		9D.2.6 Residual Stress Distribution Reference Point
		9D.2.7 Use of Alternative Residual Stress Solutions
		9D.2.8 Residual Stress Distributions from Welding Simulation
	9D.3 Data Requirements and Definition of Variables
		9D.3.1 Required Data
		9D.3.2 Optional Data
		9D.3.3 Yield Strength in Residual Stress Calculations
	9D.4 Residual Stress Distribution Modifying Factors
		9D.4.1 Post Weld Heat Treatment
		9D.4.2 Pressure Tests
	9D.5 Full Penetration Circumferential Welds in Piping & Pressure Vessel Cylindrical Shells
		9D.5.1 Residual Stress Perpendicular to the Weld Seam (Circumferential Flaw)
		9D.5.2 Residual Stress Parallel to the Weld Seam (Longitudinal Flaw)
		9D.5.3 Technical Basis
	9D.6 Full Penetration Longitudinal Welds in Piping & Pressure Vessel Cylindrical Shells
		9D.6.1 Residual Stress Perpendicular to the Weld Seam (Longitudinal Flaw)
		9D.6.2 Residual Stress Parallel to the Weld Seam (Circumferential Flaw)
		9D.6.3 Technical basis
	9D.7 Full Penetration Circumferential Welds in Spheres and Pressure Vessel Heads
		9D.7.1 Residual Stress Perpendicular to the Weld Seam (Circumferential Flaw)
		9D.7.2 Residual Stress Parallel to the Weld Seam (Meridional Flaw)
		9D.7.3 Technical Basis
	9D.8 Full Penetration Meridional (Seam) Welds in Spheres and Pressure Vessel Heads
		9D.8.1 Residual Stress Perpendicular to the Weld Seam (Meridional Flaw)
		9D.8.2 Residual Stress Parallel to the Weld Seam (Circumferential Flaw)
		9D.8.3 Technical Basis
	9D.9 Full Penetration Welds in Storage Tanks
	9D.10 Full Penetration Welds at Corner Joints (Nozzles or Piping Branch Connections)
		9D.10.1 Corner Joint, Set-In Nozzle Weld (See Figure 9D.7 and Figure 9D.8, Weld Joint A)
			9D.10.1.1 Residual Stress Perpendicular to the Weld Seam (See Figure 9D.9)
			9D.10.1.2 Residual Stress Parallel to the Weld Seam (See Figure 9D.9)
		9D.10.2 Corner Joint, Set-On Nozzle Weld (See Figure 9D.7 and Figure 9D.8, Weld Joint B)
			9D.10.2.1 Residual Stress Perpendicular to the Weld Seam
			9D.10.2.2 Residual Stress Parallel to the Weld Seam
		9D.10.3 Reinforcing Pad Shell Fillet Weld (See Figure 9D.7 and Figure 9D.8, Weld Joint C)
			9D.10.3.1 Residual Stress Perpendicular to the Weld Seam
			9D.10.3.2 Residual Stress Parallel to the Weld Seam
		9D.10.4 Piping Branch Connection (See Figure 9D.11)
			9D.10.4.1 Residual Stress Perpendicular to the Weld Seam (See Figure 9D.11)
			9D.10.4.2 Residual Stress Parallel to the Weld Seam (see Figure 9D.11)
		9D.10.5 Technical Basis
	9D.11 Full Penetration and Fillet Welds at a Tee Joint
		9D.11.1 Main Plate (See Figure 9D.12, Figure 9D.13 and Figure 9D.15)
			9D.11.1.1 Residual Stress Perpendicular to the Weld Seam
			9D.11.1.2 Residual Stress Parallel to the Weld Seam
		9D.11.2 Stay Plate (See Figure 9D.12, Figure 9D.14 and Figure 9D.15)
			9D.11.2.1 Residual Stress Perpendicular to the Weld
			9D.11.2.2 Residual Stress Parallel to the Weld Seam
		9D.11.3 Technical Basis
	9D.12 Repair Welds
		9D.12.1 Residual Stress Perpendicular to the Weld
		9D.12.2 Residual Stress Parallel to the Weld Seam
		9D.12.3 Technical Basis
	9D.13 Welding Simulation-Based Stress Distributions
		9D.13.1 General
		9D.13.2 Description of Simplified Method
		9D.13.3 Simulation References
	9D.14 Nomenclature
	9D.15 References
	9D.16  Tables
	9D.17 Figures
Annex 9E – Crack Opening Areas
	9E.1 Introduction
		9E.1.1 Scope
		9E.1.2 Overview of Crack Opening Area Calculations
			9E.1.2.1 The solutions for cylinders and spheres effectively assume that the cracks are in the center of an infinite body and away from structural discontinuities.  For most geometries this will be a reasonable approximation.  However, if the crack is...
			9E.1.2.2 Mean material properties should be used to provide a best estimate of the COA.  These properties should be relevant to the expected condition of the component; time dependent changes in properties, such as degradation, relaxation and redistri...
			9E.1.2.3 Through-wall bending stresses can induce elastic crack face rotations that reduce the effective crack opening area.  If complete crack closure occurs, a LBB analysis cannot be justified.  Significant local through-wall bending stresses may be...
			9E.1.2.4 The effects on crack face rotations due to welding residual stresses should be evaluated (see reference [8]).
			9E.1.2.5 The orientation of the net-section bending moment with respect to the through-wall crack should be considered when determining the COA in a cylindrical shell.  The orientation of the net-section bending moment may cause an asymmetric crack op...
	9E.2 Crack Opening Areas (COA) for Cylinders and Spheres
		9E.2.1 Longitudinal Cracks in Cylinders
			9E.2.1.1 For internal pressure, the crack opening area is given by:
			9E.2.1.2 For a uniform and linear through-wall stress distribution, the crack opening area is given by the following equation where  and  are determined in accordance with Annex 9B.
		9E.2.2 Circumferential Cracks in Cylinders
			9E.2.2.1 For internal pressure, the crack opening area is given by:
			9E.2.2.2 For a uniform and linear through-wall stress distribution, the crack opening area is given by the following equation where  and  are determined in accordance with Annex 9B.
			9E.2.2.3 For the global bending moment, the crack opening area is:
		9E.2.3 Meridional Cracks in Spheres
			9E.2.3.1 For internal pressure, the crack opening area is given by:
			9E.2.3.2 For a uniform and linear through-wall stress distribution, the crack opening area is given by the following equation where  and  are determined in accordance with Annex 9B.
		9E.2.4 Plasticity Correction for the COA
		9E.2.5 Nomenclature
		9E.2.6 References
		9E.2.7  Tables
Annex 9F – Material Properties FOr Crack-Like Flaws
	9F.1 General
	9F.2 Charpy V-Notch Impact Energy
		9F.2.1 Definition
		9F.2.2 Charpy V-Notch (CVN) Test
		9F.2.3 Charpy V-Notch Transition Curve
		9F.2.4 Charpy Transition Curves and ASME Division 1 and 2 Toughness Exemption Curves
			9F.2.4.1 The ASME Codes, Section VIII, Divisions 1 and 2 have toughness requirements for materials of construction based on the design conditions for a pressure vessel.  A variation of these toughness requirements have also been adopted by the ASME B3...
			9F.2.4.2 The Charpy Transition Curve consistent with the ASME Section VIII, Division 1 and 2 toughness exemption curves may be determined using Equation  in combination with the following equations.
			9F.2.4.3 A reference temperature consistent with the ASME Section VIII, Division 1 and 2 toughness exemption curves, , may be established for a material using Equation  in combination with Equations  through .  If the reference temperature is used to ...
			9F.2.4.4 A relationship between the expected temperature for an associated Charpy energy value for materials with an assigned ASME Exemption Curve may be determined using Equation  in combination with Equations (9F.21) through .
	9F.3 Fracture Toughness
		9F.3.1 Definition
		9F.3.2 Fracture Toughness Parameters
			9F.3.2.1 For most materials and structures covered by this Standard, it is possible to measure toughness only in terms of  and CTOD; valid  data can only be obtained for brittle materials or thick sections.  It is possible, however, to infer "equivale...
		9F.3.3 Fracture Toughness Testing
			9F.3.3.1 Ideally, fracture toughness tests should be heat specific, which necessitates removing specimens from the material under consideration.  This can be accomplished in one of three ways:
			9F.3.3.2 The following items should be noted if testing of a sample is to be performed to determine the fracture toughness of a material for a Fitness-For-Service assessment.
			9F.3.3.3 A measure of the fracture tearing resistance as a function of the amount of stable ductile tearing is provided by determination of a JR-curve.  Testing methods for the determination of JR-curves are covered in ASTM 1820.  It should be noted t...
		9F.3.4 Fracture Toughness Estimation from Charpy V-Notch Data
		9F.3.5 ASME B&PV Code, Section VIII Division 1 and 2 Fracture Toughness
	9F.4 Fracture Toughness Estimation for an FFS Assessment
		9F.4.1 Introduction
		9F.4.2 ASME Section XI Fracture Toughness – Lower Bound
			9F.4.2.1 When fracture toughness data are not available, an indexing procedure based on a reference temperature can provide a conservative lower-bound estimate of fracture toughness for a ferritic material.
			9F.4.2.2 A recommended procedure for determining lower bound toughness based on ASME Section XI Reference Curves is shown below.
		9F.4.3 Assessing Fracture Toughness Carbon and Low Alloys Steels – Transition Region
			9F.4.3.1 Transition Temperature Estimation
			9F.4.3.2 Fracture Toughness Estimation
		9F.4.4 Assessing Fracture Toughness Carbon and Low Alloys Steels – Upper Shelf
		9F.4.5 Dynamic Fracture or Arrest Toughness
			9F.4.5.1 Dynamic and Arrest Toughness Definition
			9F.4.5.2 Dynamic and Arrest Toughness Estimation
		9F.4.6 Fracture Toughness for Materials Subject to In-Service Degradation
			9F.4.6.1 The inherent fracture toughness of a material can be affected by the service environment.  For example, hydrogen can diffuse into the steel and can result in an apparent loss of fracture toughness.  Temperature exposure can produce embrittlem...
			9F.4.6.2 Hydrogen dissolved in ferritic steel can significantly reduce the apparent fracture toughness of a material.  Fracture initiation is enhanced when hydrogen diffuses to the tip of a crack.  If rapid unstable crack propagation begins, however, ...
			9F.4.6.3 There are several types of metallurgical embrittlement listed below that can reduce the ductility and fracture properties of carbon, alloy, and stainless steels below the  curve.
		9F.4.7 Aging Effects on the Fracture Toughness of Cr-Mo Steels
			9F.4.7.1 The effect of embrittlement due to service conditions on the fracture toughness can be estimated for certain Cr-Mo steels based on chemistry
			9F.4.7.2 The effect of tramp elements on the fracture toughness of 1.25Cr-0.5Mo (see paragraph 9F.4.6.3.a.2) may be estimated based on knowledge of the material chemistry using a two-step correlation in reference [9].
			9F.4.7.3 The effect of temper embrittlement on the fracture toughness of 2.25Cr–1Mo (see paragraph 9F.4.6.3.a.3), may be estimated based on knowledge of the material chemistry using a two-step correlation reference [9].
		9F.4.8 Fracture Toughness of Austenitic Stainless Steel
			9F.4.8.1 In most cases, austenitic stainless steels do not experience a ductile-brittle transition like ferritic steels.  The fracture toughness is usually high, even at low temperatures, provided the material has not experienced degradation in toughn...
			9F.4.8.2 If specific information on the fracture toughness is not available, the following values can be used in an assessment provided the material has not experienced significant thermal degradation and does not exhibit a transition region.
		9F.4.9 Fracture Toughness Estimation for Brittle Fracture Assessments
	9F.5 Material Data for Crack Growth Calculations
		9F.5.1 Categories of Crack Growth
			9F.5.1.1 Crack Growth by Fatigue – Crack growth by fatigue occurs when a component is subject to time varying loads that result in cyclic stresses.  Each increment of crack extension correlates to a certain increment of stress cycles.  Linear elastic ...
			9F.5.1.2 Crack Growth by Stress Corrosion Cracking (SCC) – Stress corrosion cracking results from the combination of a corrosive environment, a static applied or residual tensile stress, and a susceptible material.  In the presence of these elements, ...
			9F.5.1.3 Crack Growth by Hydrogen Assisted Cracking (HAC) – This covers a broad range of crack growth mechanisms that are associated with absorbed hydrogen in the metal.  This includes hydrogen embrittlement, hydrogen induced cracking (HIC), stress-or...
			9F.5.1.4 Crack Growth by Corrosion Fatigue – The synergistic effect of combined SCC or HAC with fatigue under cyclic loading in an aggressive environment can produce significantly higher crack growth per cycle compared to an inert environment where SC...
		9F.5.2 Fatigue Crack Growth Equations
			9F.5.2.1 Overview
			9F.5.2.2 Paris Equation
			9F.5.2.3 Walker Equation
			9F.5.2.4 Trilinear and Bilinear Equations
			9F.5.2.5 Modified Forman Equation
			9F.5.2.6 NASGRO Equation
			9F.5.2.7 Collipriest Equation
		9F.5.3 Fatigue Crack Growth Data
			9F.5.3.1 When possible, fatigue crack growth data should be evaluated from test results in a similar environment since this can greatly affect the crack growth rate.  Sources for fatigue crack growth data,        , for various materials and service en...
			9F.5.3.2 The fatigue crack growth equations shown below can be used with the Paris Equation (see paragraph 9F.5.2.2), in  assessments (see reference [15]).  These equations are valid for materials with yield strengths less than or equal to .
			9F.5.3.3 The fatigue crack growth equations shown below can be used with the Paris Equation, (see paragraph 9F.5.2.2) in  assessments (see Reference [14]).  These parameters correspond to upper bound crack growth data.
			9F.5.3.4 The fatigue crack growth equations shown below can be used with the Paris Equation (see paragraph 9F.5.2.2) in  assessments (see reference [14]).  These equations are based on data determined from crack propagation testing of as-welded joints.
			9F.5.3.5 Fatigue crack growth parameters for use with the Bilinear Equation (see paragraph 9F.5.2.4) are provided below.
			9F.5.3.6 Fatigue crack growth parameters for use with the NASGRO Equation (see paragraph 9F.5.2.6) are given in reference [12] for different materials and service environments.
			9F.5.3.7 ASME B&PV Code, Section XI
		9F.5.4 Stress Corrosion Crack Growth Equations
			9F.5.4.1 Within the LEFM methodology, a Stress Corrosion Crack (SCC) growth law can be experimentally determined which relates the crack growth rate to the stress intensity factor (), the material, service environment, and time.  This crack growth mod...
			9F.5.4.2 An overview of stress corrosion crack growth models is provided in References [10], [11], and [21].  Examples of SCC crack growth models that have been used are shown below.
		9F.5.5 Stress Corrosion Crack Growth Data
			9F.5.5.1 When possible, stress corrosion crack growth data should be evaluated from test results in a similar environment since this can greatly affect the crack growth rate.  Sources for stress corrosion crack growth data, , for various materials and...
			9F.5.5.2 An upper bound solution for a hydrogen assisted crack growth rate in 2.25Cr-0.5Mo and the associated threshold stress intensity factor is shown below.  The tests for the data were conducted in a 500 ppm  solution.
	9F.6 Nomenclature
	9F.7 References
	9F.8  Tables
	9F.9  Figures
Annex 9G – Stress Analysis For Crack-Like Flaws
	9G.1 General Requirements
		9G.1.1 Scope
		9G.1.2 ASME B&PV Code, Section VIII, Division 2 (VIII-2)
		9G.1.3 FAD-Based Assessment Procedure
		9G.1.4 Assessment Using Stress Analysis Results – Uncracked Configuration
		9G.1.5 Assessment Using Stress Analysis Results – Crack Incorporated into the Model
		9G.1.6 Assessment of Growing Cracks
		9G.1.7 Numerical Analysis
		9G.1.8 Applicable Loads and Load Case Combinations
	9G.2 Stress Analysis of the Un-Cracked Configuration
		9G.2.1 Overview
		9G.2.2 Categorization and Linearization of Stress Results
		9G.2.3 Fitting Stress Results to a Polynomial
		9G.2.4 The Weight Function Method
	9G.3 Finite Element Analysis of Components with Cracks
		9G.3.1 Overview
		9G.3.2 Output Quantity
		9G.3.3 Mesh Design
		9G.3.4 Crack Tip Modeling Approaches
		9G.3.5 Focused Mesh Approach
		9G.3.6 Finite Radius Approach
		9G.3.7 Small Strain vs. Large Strain Analysis
		9G.3.8 Convergence
		9G.3.9 Initial and Thermal Strains
		9G.3.10 Modeling Procedure
	9G.4 FAD-Based Method for Non-Growing Cracks
		9G.4.1 Overview
		9G.4.2 Assessment Procedure
	9G.5 Driving Force Method for Non-Growing Cracks
		9G.5.1 Overview
		9G.5.2 Assessment Procedure
	9G.6 Assessment of Growing Cracks
		9G.6.1 Crack Growth Models
		9G.6.2 Crack Parameter Solutions
		9G.6.3 Determination of a Remaining Life
		9G.6.4 Crack Growth Using Numerical Methods
	9G.7 Nomenclature
	9G.8 References
	9G.9  Figures
Part 10  – Assessment Of Components Operating In The Creep Range
	10.1 General
		10.1.1 FFS Procedures and Temperature Limits
		10.1.2 Remaining Life of Components with and without Crack-Like Flaws
	10.2 Applicability and Limitations of the Procedure
		10.2.1 Suitability for Service and Remaining Life
		10.2.2 Applicability and Limitations
			10.2.2.1 The Level 1 assessment procedures apply only if all of the following conditions are satisfied:
			10.2.2.2 The Level 2 assessment procedures apply only if all of the following conditions are satisfied:
			10.2.2.3 A Level 3 Assessment should be performed when the Level 1 and 2 methods cannot be applied due to applicability and limitations of the procedure or when the results obtained indicate that the component is not suitable for continued service.
			10.2.2.4 To perform an evaluation to any of the assessment levels, the material properties for the temperature and stress conditions the component is subject to must be available.  For a Level 1 Assessment, the required material properties are include...
	10.3 Data Requirements
		10.3.1 General
			10.3.1.1 The Level 1 Assessment is a screening criterion based on the original design of the component, the past and future planned operating conditions.  This assessment can be performed based on the following information.
			10.3.1.2 Significant input data are required to perform a Level 2 or Level 3 Assessment.  Details regarding the required data are discussed in paragraphs 10.3.2 through 10.3.6.  The accuracy of these data and stress conditions will determine the accur...
		10.3.2 Original Equipment Design Data
		10.3.3 Maintenance and Operational History
			10.3.3.1 An overview of the maintenance and operational history required for an assessment is provided in Part 2, paragraph 2.3.2.
			10.3.3.2 The definition of the operating history is required in order to perform a  assessment of a component operating in the creep range.
		10.3.4 Required Data for a FFS Assessment – Loads and Stresses
			10.3.4.1 A stress analysis is required for a Level 2 or Level 3 Assessment.
			10.3.4.2 Stress calculations shall be performed for all points included in the load histogram (see paragraph 10.3.3.2) that will be used in the assessment.
			10.3.4.3 The stress analysis performed for all assessment levels shall include the effects of service-induced wall thinning (e.g. oxidation).
			10.3.4.4 Additional information regarding stress analysis for a component containing a crack-like flaw is provided in Part 9, paragraph 9.3.4.2.
			10.3.4.5 Component temperatures used in an assessment should be based on the operating temperatures considering the following.
		10.3.5 Required Data for a FFS Assessment – Material Properties
			10.3.5.1 An overview of the material data required to perform a remaining life assessment is provided in Annex 10B and summarized below.  The material data presented in Annex 10B are from the MPC Project Omega data that are based on a strain-rate appr...
			10.3.5.2 As previously described, a precise description of the component operating history and future operational conditions is required to perform a remaining life assessment.  The future planned operating conditions can be readily defined; however, ...
			10.3.5.3 The material data from the MPC Project Omega Program (see Annex 10B) can be used directly to model creep behavior in an inelastic finite element analysis by implementing the equation shown below.  This equation provides a strain-hardening rel...
			10.3.5.4 If the component contains a crack-like flaw, parameters for the creep-crack growth equation is required (see Annex 10B).  In addition, the fracture toughness is also required because an evaluation of the flaw using the Failure Assessment Diag...
		10.3.6 Required Data for a FFS Assessment – Damage Characterization
			10.3.6.1 General requirements for all components
			10.3.6.2 Supplemental requirements for a component with a crack-like flaw
		10.3.7 Recommendation for Inspection Technique and Sizing Requirements
			10.3.7.1 General requirements for all components
			10.3.7.2 Nondestructive material examination by means of replication is a metallographic examination method that exposes and replicates the microstructure of the surface material.
			10.3.7.3 As an alternative to replication, small samples can be removed from the component to determine composition as well as microstructure.  However, it should be noted that repair of this area may be required unless the region can be qualified for...
			10.3.7.4 Supplemental requirements for a component with a crack-like flaw
	10.4  Assessment Techniques and Acceptance Criteria
		10.4.1 Overview
			The  assessment procedures used to evaluate the remaining life of a component operating in the creep range are described below.  The three assessment levels used to evaluate creep damage are based on the data and details required for the analysis, whe...
		10.4.2 Level 1 Assessment
			10.4.2.1 The Level 1 assessment for a component subject to a single design or operating condition in the creep range is provided below.
			10.4.2.2 The Level 1 assessment for a component subject to a multiple design or operating conditions in the creep range is shown below.
			10.4.2.3 If the component does not meet the Level 1 Assessment requirements, then the following, or combinations thereof, can be considered:
		10.4.3 Level 2 Assessment
			10.4.3.1 The Level 2 assessment procedure shall be performed in accordance with paragraph 10.5.2.3.  The temperature of the component used in the assessment is assumed to be uniform for each specific time step.
			10.4.3.2 If the component does not meet the Level 2 Assessment requirements, then the following, or combinations thereof, can be considered:
		10.4.4 Level 3 Assessment
			10.4.4.1 The Level 3 Assessment procedures are covered in paragraph 10.5.  With the exception of the procedure for the evaluation of dissimilar metal welds, these procedures can also be used to evaluate a component containing one or more of the flaws ...
			10.4.4.2 If the component does not meet the Level 3 Assessment requirements, then the following, or combinations thereof, can be considered:
	10.5  Remaining Life Assessment
		10.5.1 Overview
			10.5.1.1 A remaining life calculation is required for all components operating in the creep range.  The assessment procedures in paragraph 10.4 are limited to components that are not subject to significant cyclic operation and/or components that do no...
			10.5.1.2 The assessment procedures described in this paragraph provide the best estimate of the structural integrity of a component operating at elevated temperature.  Five assessment procedures are provided.
			10.5.1.3 The recognized assessment procedures listed below may be used as an alternative to the procedures in paragraph 10.5.1.2.  Other assessment procedures may be used if the technology used adequately addresses the damage mechanism, a remaining li...
			10.5.1.4 A sensitivity analysis, (see Part 2, paragraph 2.4.3.1) should be performed as part of the assessment regardless of the method chosen.
		10.5.2 Creep Rupture Life
			10.5.2.1 The following analysis procedure can be utilized to evaluate a component operating in the creep range using the results from a stress analysis.  The assessment is based on the stresses and strains at a point and through the wall thickness in ...
			10.5.2.2 The assessment procedure in this paragraph provides a systematic approach for evaluating the creep damage for each operating cycle that is applied to the component.  The total creep damage is computed as the sum of the creep damages calculate...
			10.5.2.3 A procedure to determine the creep damage based upon the results of a stress analysis is shown below.  This procedure is based on computation of stresses at discrete times during the load history.  The stresses may be based on elastic analysi...
			10.5.2.4 As an alternative to the procedure in paragraph 10.5.2.3, an inelastic analysis including the effects of creep may be performed based on the procedure shown below.  This procedure is defined in terms of integral equations as opposed to the di...
			10.5.2.5 Fired heater and boiler tubes may be evaluated as a special case of the procedure in paragraph 10.5.2.3 if the pressure is approximately constant and temperature is approximately uniform around the circumference of the tube during operation.
		10.5.3 Creep-Fatigue Interaction
			10.5.3.1 If there are significant cyclic operations during the operating period, then the effects of combined creep and fatigue damage shall be evaluated.  The combination of creep and fatigue damage is may evaluated using the following procedure.
			10.5.3.2 In lieu of the procedure given in paragraph 10.5.3.1, ASME Code Case 2605 may be used to evaluate creep-fatigue damage for components constructed from 2.25Cr-1Mo-V.
		10.5.4 Creep Crack Growth
			10.5.4.1 The following analysis procedure can be utilized to evaluate a component operating in the creep range with a crack-like flaw using the results from a stress analysis.  The assessment is based on the stresses and strains at a point and through...
			10.5.4.2 A procedure to determine creep crack growth based upon the results of a stress analysis is shown below.
		10.5.5 Creep Buckling
			10.5.5.1 The in-service margin for protection against collapse from buckling shall be satisfied to avoid buckling of components with a compressive stress field under applied design loads.
			10.5.5.2 The rules for external pressure and compressive stress design in Annex 2B may be used if the strain rate computed using Equation  based on the membrane stress for the most severe combination of applied loads that results in compressive stress...
			10.5.5.3 The following analysis method may be used to estimate the critical time for creep buckling in the creep range.  The cylindrical shell cannot contain a major structural discontinuity.  If the cylindrical shell contains a major structural disco...
			10.5.5.4 In lieu of the procedure in paragraph 10.5.5.3, the critical time for creep buckling may be estimated by using the allowable compressive stress rules in Annex 2D with a time-dependent tangent modulus evaluated using Annex 10B.  This assessmen...
		10.5.6 Creep-Fatigue Assessment of Dissimilar Weld Joints
			10.5.6.1 The metallurgical characteristics of the damage observed in both service and laboratory test samples indicate that creep rupture is the dominant failure mode for Dissimilar Metal Welds (DMW).  However, it has also been observed that temperatu...
			10.5.6.2 The damage mechanism of concern is creep damage in the Heat-Affected Zone (HAZ) on the ferritic steel side of the DMW.  Damage in this region is expected to occur first because the creep resistance of the material, at the temperatures of inte...
			10.5.6.3 The assessment procedure in this paragraph provides a systematic approach for evaluating the creep-fatigue Mode I and Mode II damage for operating cycles that are applied to a DMW in a component.
			10.5.6.4 The Mode I creep-fatigue damage based on the results of a stress analysis can be computed using the assessment procedure shown below.  This mode of failure is only applicable to a DMW made with stainless steel or nickel-based filler metal.  N...
			10.5.6.5 The Mode II creep-fatigue damage based upon the results of a stress analysis can be computed using the assessment procedure shown below.  This mode of failure is only applicable to a DMW made with nickel-based filler metal.  Note that the dam...
		10.5.7 Microstructural Approach
			10.5.7.1 Microstructural Approach Overview
			10.5.7.2 Microstructural approaches have been used to estimate the remaining life of a component.  The following procedures are recognized.
	10.6  Remediation
		10.6.1 Components with and without a Crack-Like Flaw
		10.6.2 Components with a Crack-Like Flaw
	10.7 In-Service Monitoring
	10.8  Documentation
		10.8.1 General
		10.8.2 Assumptions Used in the Assumptions
		10.8.3 Documentation for Life Assessment
		10.8.4 Supplemental Documentation for Creep Crack Growth
		10.8.5 Supplemental Documentation for Microstructural Approaches
	10.9 Nomenclature
	10.10 References
	10.11 Tables
	10.12 Figures
Annex 10A  – Technical Basis And Validation – Assessment Of Components Operating In The Creep Range
	10A.1 Technical Basis and Validation
	10A.2 Technical Basis and Validation References
	10A.3 Additional References
Annex 10B  – Material Data For Creep Analysis
	10B.1 General
	10B.2 Creep Rupture Data
		10B.2.1 MPC Project Omega
		10B.2.2 API Std 530, 6th Edition, September 2008
		10B.2.3 WRC Bulletin 541
	10B.3 Tangent and Secant Modulus
	10B.4 Creep Strain-Rate Data
	10B.5 Isochronous Stress-Strain Curves
	10B.6 Creep Regime Fatigue Curves (Crack Initiation)
	10B.7 Creep Crack Growth Data
	10B.8 Nomenclature
	10B.9 References
		10B.9.1 Technical References – High Temperature Assessment
		10B.9.2 Creep Rupture Strength and Creep Strain Rate Data
		10B.9.3 Creep Crack Growth Data
	10B.10  Tables
Part 11  – Assessment Of Fire Damage
	11.1 General
		11.1.1 Assessment of Fire Damage
		11.1.2 Assessment of Process Upsets
		11.1.3 Guidelines and Assessment Flowchart
		11.1.4 Forms of Fire Damage
		11.1.5 Alternative Methods for Equipment Not Suitable for Operation
	11.2 Applicability and Limitations of the Procedure
		11.2.1 Equipment and Components Covered by the Assessment Procedure
		11.2.2 Equipment and Components Not Covered by the Assessment Procedure
	11.3 Data Requirements
		11.3.1 Original Equipment Design Data
		11.3.2 Maintenance and Operational History
		11.3.3 Required Data/Measurements for a FFS Assessment
			11.3.3.1 Fire Damage Evidence
			11.3.3.2 Record of the Fire Incident
			11.3.3.3 Heat Exposure Zones
			11.3.3.4 Degradation Associated with Heat Exposure
			11.3.3.5 The typical material degradation and appearance of the microstructure that may occur in carbon steel, low alloy steels, and stainless steel are shown in Table 11.12.  These degradations shall be considered in the judgment to reuse the compone...
			11.3.3.6 Data and Measurements for Components Subject To Heat Exposure
			11.3.3.7 Evaluation of Mechanical Properties for Components Subject To Heat Exposure
		11.3.4 Recommendations for Inspection Techniques and Sizing Requirements
			11.3.4.1 Shell dimensional profiles should be taken for equipment subjected to fire damage.  Dimensional profiles of vertical vessels can be obtained by dropping a reference vertical line from the top of the vessel, and measuring the bulges and dents ...
			11.3.4.2 Evaluation of the impact of relatively high temperature exposure to the microstructure of the material and its mechanical properties may be needed to determine if equipment or a component involved in a fire event can be returned to service or...
			11.3.4.3 Other inspection techniques, such as magnetic particle testing, dye penetrant testing, and ultrasonic testing may be needed based on the observed or suspected deterioration mode (see paragraph 11.3.3.4).
			11.3.4.4 Leak testing of mechanical equipment subject to fire- damage in Heat Exposure Zones IV and higher should be considered prior to returning the equipment to service.  The types of equipment included are:
				a) Flanged connections.
				b) Threaded connections which are not seal-welded.
				c) Valves (i.e. both shell and closure test per API 598 should be considered).
				d) Gaskets and packing.
				e) Heat exchanger tube sheet rolled joints.
	11.4 Assessment Techniques and Acceptance Criteria
		11.4.1 Overview
			a) The Level 1 assessment procedure is a screening criterion where the acceptability for continued service is based on the Heat Exposure Zone and the material of construction.  The screening criteria are conservative, and calculations are not required...
			b) The Level 2 assessment procedure determines the structural integrity of a component by evaluating the material strength of a fire-damaged component.  Assessment procedures include evaluation methods for flaws and damage incurred during the fire (e....
			c) The Level 3 Assessment procedures may be utilized if the current material strength of the component established using the Level 2 Assessment procedures result in an unacceptable evaluation.  Replication or in-situ field metallography, hardness test...
		11.4.2 Level 1 Assessment
			11.4.2.1 The objective of this Level 1 assessment is to gather and document the observations and data used to justify assigning a Heat Exposure Zone to each component.  Components do not need a further assessment of mechanical properties if they are a...
			11.4.2.2 Gasket inspections and leak checking of flange joints should be included in a startup check list for components passing a Level 1 assessment.
			11.4.2.3 Protective coating damage can occur for some components that satisfy the Level 1 acceptance criteria.  Protective coatings required for external or internal corrosion resistance must be repaired prior to startup.
			11.4.2.4 If the component does not meet the Level 1 Assessment requirements, then the following, or combinations thereof, may be considered:
		11.4.3 Level 2 Assessment
			11.4.3.1 Pressurized components that do not pass a Level 1 Assessment may be evaluated for continued service using a Level 2 Assessment.  This evaluation should consider the degradation modes described in paragraph 11.3.3.4.
			11.4.3.2 An overview of the Level 2 assessment procedure is provided in Figure 11.6.
				a) The first step in the assessment is to conduct dimensional checks on pressure components.  The dimensional checks generally take the following forms; overall out-of-plumb or sagging of the component(s) and localized shell distortion.  As listed bel...
				b) Hardness testing is used to estimate the approximate tensile strength of a fire exposed component made of carbon and/or low alloy steel.  The information is subsequently used with the rerating procedures in this document to establish an acceptable ...
				c) Components that experience dimensional changes provide insight into the additional evaluations that are required.  This insight is based on the observation that carbon steel equipment does not experience a significant reduction in short term high t...
			11.4.3.3 The following procedure may be used to evaluate a pressurized component constructed of carbon or low alloy steels for continued operation if the mechanical strength properties are suspected to have been degraded by the fire exposure.
				a) STEP 1 – If the component is fabricated from carbon and/or low alloy steel, perform a hardness test on the component (see Annex 11B) and convert the resulting hardness value into an estimated ultimate tensile strength using Annex 2E, Table 2E.1.  I...
				b) STEP 2 – Determine an allowable stress for the fire damaged component based on the estimated ultimate tensile stress determined in STEP 1 using Equation (11.1).  In this equation, the parameter  is the in-service margin.  The in-service margin may ...
			11.4.3.4 Other effects that should be considered in the assessment include the following:
				a) Internal attachments that may have been subject to large thermal gradients during a fire should be inspected for cracks on the component surface and at the attachment weld.  This inspection is especially important for internal components fabricated...
				b) Pressure components being rerated because of the reduction in mechanical properties should be assessed if there is a plausible reason to expect a change in the corrosion resistance or susceptibility to environmental cracking in the service which th...
			11.4.3.5 The beneficial effects of PWHT (stress relief) may have been compromised because of heat exposure.  Pressurized components that were subjected to PWHT in accordance with the original construction code (i.e. based on the material and thickness...
				a) For carbon steel, the issue is usually on relief of residual stresses, but sometimes also on tempering hard zones in the microstructure or on improved toughness.  Distortion and/or quenching in fire-fighting efforts can leave the component with hig...
				b) For low alloy steels, the issue is usually on retaining mechanical properties.  The original PWHT was conducted to temper a hard microstructure and/or to improve toughness.  Heat exposure can lead to a very hard/brittle microstructure in the compon...
			11.4.3.6 If the component does not meet the Level 2 Assessment requirements, then the following, or combinations thereof, may be considered:
				a) Repair, replace or retire the component,
				b) Adjust the future corrosion allowance, , by applying remediation techniques (see Part 4, paragraph 4.6),
				c) Adjust the weld joint efficiency factor, , by conducting additional examination and repeat the assessment (see Part 4, paragraph 4.4.2.2.c), and/or
				d) Conduct a Level 3 Assessment.
		11.4.4 Level 3 Assessment
			11.4.4.1 A Level 3 assessment of a fire damaged component may be performed if the component does not satisfy the Level 1 or Level 2 Assessment criteria.  A Level 3 assessment is usually performed for the following reasons.
				a) The  (or ) calculations associated with a Level 2 Assessment cannot be used to adequately represent the current condition of the component.  If the component is severely deformed or shell distortions are located in the region of a major structural ...
				b) The current strength of the material established from a hardness test taken on the material surface is an approximation of the actual tensile strength of the material that in some cases could be conservative, resulting in a reduction of the  (or )....
			11.4.4.2 A Level 3 assessment of a known fire-damaged component shall be conducted if an increase in the original  (or temperature) is required.  A representative sample of the base metal and weld should be tested to establish an acceptable allowable ...
	11.5 Remaining Life Assessment
		11.5.1 Thinning and Crack-Like Flaw Damage
		11.5.2 Creep Damage
	11.6 Remediation
		11.6.1 Techniques
		11.6.2 Need for Repair or Replacement
	11.7 In-Service Monitoring
	11.8 Documentation
		11.8.1 General
		11.8.2 Heat Exposure Zones
		11.8.3 Record Retention
	11.9 Nomenclature
	11.10 References
	11.11 Tables
	11.12  Figures
Annex 11A  – Technical Basis And Validation – Assessment Of Fire Damage
	11A.1 Technical Basis and Validation
	11A.2 References
Annex 11B – Metallurgical Investigation And Evaluation Of Mechanical Properties In Fire Damage Assessment
	11B.1 General
		11B.1.1 Metallurgical Investigations
		11B.1.2 Materials Covered
		11B.1.3 Change in material properties from Fire Damage
	11B.2 Applicability and Limitations of the Procedure
	11B.3 Specific Responsibilities and Qualifications
		11B.3.1 Overview
		11B.3.2 Field Assessment Team
		11B.3.3 Laboratory Assessment Team
	11B.4 Evaluation Techniques
	11B.5 Field Assessment Techniques
		11B.5.1 Field Hardness Testing
		11B.5.2 In-situ Metallography or Replication
		11B.5.3 Positive Material Identification
	11B.6 Laboratory Assessment Techniques
		11B.6.1 Coupon or Sample Removal
		11B.6.2 Metallurgical Mounts and Mechanical Testing Specimens
	11B.7 Work Procedure
		11B.7.1 STEP 1 – Select Equipment and Component Subject to Analysis
		11B.7.2 STEP 2 – Select Sampling Technique(s)
		11B.7.3 STEP 3 – Perform In-situ Metallography or Replica Evaluation
		11B.7.4 STEP 4: Take Field Hardness Readings
		11B.7.5 STEP 5: Remove Samples for Laboratory Analysis and Mechanical Testing (Optional)
	11B.8 Guidance for Metallographic Analysis and Mechanical Testing Interpretation
		11B.8.1 Overview
		11B.8.2 Reduction in Tensile Strength
		11B.8.3 Reduction in Toughness
		11B.8.4 Decrease of Corrosion Resistance
		11B.8.5 Consideration for Reuse
		11B.8.6 Heat Treatment
	11B.9 Example of Metallography Analysis and Hardness Testing Results
		11B.9.1 Overview
		11B.9.2 Samples
		11B.9.3 Test Sequence
		11B.9.4 Test Results – Metallography
		11B.9.5 Test Results – Hardness
	11B.10 Figures
Part 12 – Assessment Of Dents, Gouges, And Dent-Gouge Combinations
	12.1 General
		12.1.1 Assessment Procedures for Dents, Gouges and Dent-Gouge Combinations
		12.1.2 Assessment Procedures for LTAs, Grooves and Other Shell Distortions
	12.2 Applicability and Limitations of the Procedure
		12.2.1 Overview
		12.2.2 Calculation of the MAWP and Coincident Temperature
		12.2.3 Limitations Based on Flaw Type
		12.2.4 Limitations Based on Temperature
		12.2.5 Applicability of the Level 1 and Level 2 Assessment Procedures
			12.2.5.1 The Level 1 or 2 assessment procedures in this Part apply only if all of the following conditions are satisfied.
			12.2.5.2 The Level 1 Assessment procedures are applicable if the component is not in cyclic service.  If the component is subject to less than 150 cycles (i.e. pressure and/or temperature variations including operational changes and start-ups and shut...
		12.2.6 Applicability of the Level 3 Assessment Procedure
	12.3 Data Requirements
		12.3.1 Original Equipment Design Data
		12.3.2 Maintenance and Operational History
		12.3.3 Required Data/Measurements for a FFS Assessment
			12.3.3.1 The required data and measurements for assessment of a dent are listed below.
			12.3.3.2 The required data and measurements for assessment of a gouge are listed below.
			12.3.3.3 The required data and measurements for assessment of a dent-gouge combination are listed below.
			12.3.3.4 The information required to perform a Level 3 Assessment is dependent on the analysis method utilized.  In most cases, stress analysis in accordance with Annex 2D and Part 14, as applicable, will be performed.  The stress analysis will typica...
		12.3.4 Recommendations for Inspection Technique and Sizing Requirements
			12.3.4.1 The maximum depth of the dent may be established using a straight edge along the axis of the cylinder and measuring the offset in the region of the dent.  Note that numerous measurements should be taken to establish the dent profile in the ax...
			12.3.4.2 The gouge dimensions may be obtained in accordance with Part 4 and Part 5.
			12.3.4.3 The flaw size of the dent-gouge combination may be established using the methods described above.
	12.4 Assessment Techniques and Acceptance Criteria
		12.4.1 Overview
			12.4.1.1 An overview of the assessment levels for the evaluation of a dent is provided below.
			12.4.1.2 An overview of the assessment levels for the evaluation of a gouge is provided below.
			12.4.1.3 An overview of the assessment levels for the evaluation of a dent-gouge combination is provided below.
		12.4.2 Level 1 Assessment
			12.4.2.1 Dent Assessment Procedure
			12.4.2.2 Gouge Assessment Procedure
			12.4.2.3 Dent-Gouge Combination Assessment Procedure
			12.4.2.4 If the component does not meet the Level 1 Assessment requirements, then the following, or combinations thereof, shall be considered:
		12.4.3 Level 2 Assessment
			12.4.3.1 Dent Assessment Procedure
			12.4.3.2 Gouge Assessment Procedure
			12.4.3.3 Dent-Gouge Combination Assessment Procedure
			12.4.3.4 If the component does not meet the Level 2 Assessment requirements (see Part 2, paragraph 2.4.2.2.e), then the following, or combinations thereof, shall be considered:
		12.4.4 Level 3 Assessment
			12.4.4.1 The Level 3 Assessment procedures for dents, gouges, and dent-gouge combinations involve the evaluation of potential failure modes based on component geometry, material of construction, loading conditions, and operating temperature range.
			12.4.4.2 The numerical stress analysis should be performed considering the material as well as geometric non-linearity in order to account for the effect of pressure stiffening on the dent and re-rounding of the shell that occurs under pressure loading.
			12.4.4.3 The stress analysis used in the assessment should simulate the deformation process that causes the damage in order to determine the magnitude of permanent plastic strain developed.  To simulate the distortion process, an analysis that include...
			12.4.4.4 If a kink or sharp bend exists in a shell, shell theory will not provide an accurate estimate of the stress state.  In this case, a continuum model is recommended in the stress analysis described in paragraph 12.4.4.3.
			12.4.4.5 For gouges and dent-gouge combinations that are evaluated using the crack-like flaw assessment procedures in Part 9 or Part 10, as applicable, the equivalent crack depth may be taken as the gouge depth and the equivalent crack length may be t...
			12.4.4.6 If the component is operating in the creep range, stresses due to localized geometric irregularities may not sufficiently relax with time due to the surrounding compliance of the component.  In this case, creep strains can accumulate and may ...
	12.5 Remaining Life Assessment
		12.5.1 Categories of Remaining Life Assessment
		12.5.2 Requirements for a Level 3 Assessment
	12.6 Remediation
		12.6.1 Flaw Severity and Evaluation of Material Condition
		12.6.2 Reinforcement of Dents, Gouges and Dent-Gouge Combinations
		12.6.3 Use of General Corrosion Remediation Methods
	12.7 In-Service monitoring
		12.7.1 Requirements for In-Service Monitoring
		12.7.2 Visual Inspection and Field Measurements of Distortion
	12.8 Documentation
		12.8.1 Requirements
		12.8.2 Inspection and Field Measurements
	12.9 Nomenclature
	12.10 References
	12.11  Tables
	12.12 Figures
Annex 12A  – Technical Basis and Validation – Assessment Of Dents, Gouges, And Dent-Gouge Combinations
	12A.1 Technical Basis and Validation
	12A.2 References
Part 13  – Assessment Of Laminations
	13.1 General
		13.1.1 Assessment Procedures for Laminations
		13.1.2 Definition of Laminations
		13.1.3 Laminations in Hydrogen Charging Service
		13.1.4 Detection of Laminations
		13.1.5 Acceptance of Laminations
	13.2 Applicability and Limitations of the Procedure
		13.2.1 Applicability and Limitations of the Assessments Procedures for Laminations
		13.2.2 Calculation of MAWP and Coincident Temperature
		13.2.3 Limitations Based on Temperature
		13.2.4 Limitations Based on Flaw Type
		13.2.5 Applicability of the Level 1 and Level 2 Assessment Procedures
		13.2.6 Applicability of the Level 3 Assessment
	13.3 Data Requirements
		13.3.1 Original Equipment Design Data
		13.3.2 Maintenance and Operational History
		13.3.3 Required Data/Measurements for a FFS Assessment
			13.3.3.1 The required data and measurements for a lamination are shown below.  This information should be recorded in Table 13.1.  In addition, the creation of a sketch at the time of the inspection showing the information in this paragraph is recomme...
		13.3.4 Recommendations for Inspection Technique and Sizing Requirements
			13.3.4.1 Laminations are usually discovered during an in-service inspection/monitoring UT examination.  If any visual observation of surface bulging on either the inside or the outside of the equipment is recorded, then the lamination shall be categor...
			13.3.4.2 Ultrasonic examination can be used to determine the depth of the lamination and remaining plate thickness at the lamination location.
	13.4 Assessment Techniques and Acceptance Criteria
		13.4.1 Overview
			13.4.1.1 The assessment procedures of this Part shall be followed to evaluate the lamination even when the lamination is located within the region of the specified corrosion/erosion allowance.
			13.4.1.2 An overview of the assessment levels for laminations is provided in Figure 13.1.
		13.4.2 Level 1 Assessment
			13.4.2.1 The following procedure shall be used to determine the acceptability of a lamination in a Type A component subject to internal pressure:
			13.4.2.2 If the component does not meet the Level 1 Assessment requirements, then the following, or combinations thereof, can be considered:
		13.4.3 Level 2 Assessment
			13.4.3.1 The following procedure shall be used to determine the acceptability of a lamination in a Type A and a Type B Class 1 component subject to internal pressure, supplemental loads, or any combination thereof.
			13.4.3.2 If the component does not meet the Level 2 Assessment requirements, then the following, or combinations thereof, can be considered:
		13.4.4 Level 3 Assessment
	13.5 Remaining Life Assessment
	13.6 Remediation
	13.7 In-Service Monitoring
	13.8 Documentation
		13.8.1 General
		13.8.2 Documentation of Flaw Size and Conditions
		13.8.3 Documentation of Flaw Growth
	13.9 Nomenclature
	13.10 References
	13.11  Tables
	13.12  Figures
Annex 13A  – Technical Basis And Validation – Assessment Of Laminations
	13A.1 Technical Basis and Validation
	13A.2 References
Part 14  – Assessment Of Fatigue Damage
	14.1 General
		14.1.1 Assessment Procedures for Fatigue Damage
		14.1.2 Damage Tolerance
		14.1.3 Fatigue Evaluation in the Creep Range
		14.1.4 Fatigue Evaluation and Crack-Like Flaws
		14.1.5 ASME B&PV Code, Section VIII, Division 2 (VIII-2)
		14.1.6 Use of Fatigue Curves in Performing Assessments
		14.1.7 Adjustment for Mean Stress
		14.1.8 Ratcheting
	14.2 Applicability and Limitations of the Procedure
		14.2.1 Applicability and Limitations of the Assessment Procedures
		14.2.2 Calculation of MAWP and Coincident Temperature
		14.2.3 Limitations Based on Temperature
		14.2.4 Limitations Based on Flaw Type
		14.2.5 Applicability of the Level 1 and Level 2 Assessment Procedures
		14.2.6 Applicability of the Level 3 Assessment
	14.3 Data Requirements
		14.3.1 Original Equipment Design Data
		14.3.2 Maintenance and Operational History
		14.3.3 Required Data/Measurements for an FFS Assessment
		14.3.4 Recommendations for Inspection Technique and Sizing Requirements
	14.4 Assessment Techniques and Acceptance Criteria
		14.4.1 Overview
		14.4.2 Level 1 Assessment
			14.4.2.1 Overview
			14.4.2.2 Method A – Fatigue Screening Based On Experience with Comparable Equipment
			14.4.2.3 Method B – Fatigue Screening
			14.4.2.4 Method C – Fatigue Screening
			14.4.2.5 Method D – Fatigue Screening, Welded Joints
			14.4.2.6 Level 1 Assessment Results
		14.4.3 Level 2 Assessment
			14.4.3.1 Overview
			14.4.3.2 Method A – Fatigue Assessment Using Elastic Stress Analysis and Equivalent Stresses
				14.4.3.2.1 Overview
				14.4.3.2.2 Assessment Procedure
				14.4.3.2.3 Alternative Method for Computing the Local Thermal Stress
				14.4.3.2.4 Alternative Method for Computing the Fatigue Penalty Factor
			14.4.3.3 Method B – Fatigue Assessment Using Elastic-Plastic Stress Analysis and Equivalent Strain
				14.4.3.3.1 Overview
				14.4.3.3.2 Assessment Procedure
				14.4.3.3.3 The Twice Yield Method
			14.4.3.4 Method C – Fatigue Assessment of Welds Using the Equivalent Structural Stress
				14.4.3.4.1 Overview
				14.4.3.4.2 Assessment Procedure
				14.4.3.4.3 Assessment Procedure Modifications
			14.4.3.5 Ratcheting Assessment – Elastic Stress Analysis
				14.4.3.5.1 Elastic Ratcheting Analysis Method
				14.4.3.5.2 Simplified Elastic-Plastic Analysis
				14.4.3.5.3 Thermal Stress Ratcheting Assessment
			14.4.3.6 Ratcheting Assessment – Elastic-Plastic Stress Analysis
				14.4.3.6.1 Overview
				14.4.3.6.2 Assessment Procedure
			14.4.3.7 Ratcheting Assessment – Non-Integral Connections
			14.4.3.8 Level 2 Assessment Results
		14.4.4 Level 3 Assessment
			14.4.4.1 Overview
			14.4.4.2 Method A – Elastic Stress Analysis and Critical Plane Approach
			14.4.4.3 Method B – Elastic-Plastic Stress Analysis and Critical Plane Approach
			14.4.4.4 Method C – Recognized Codes and Standards
	14.5 Remaining Life Assessment
		14.5.1 Included in Level 2 and Level 3 Assessments
		14.5.2 Loading Time History
	14.6 Remediation
		14.6.1 Overview
		14.6.2 Removal or Reduction of the Driving Energy Source or Forces
		14.6.3 Alteration of Component Constraint, Mechanical Design, or Weld Quality
		14.6.4 Reduction of Temperature Differentials or Gradients
	14.7 In-Service Monitoring
	14.8 Documentation
		14.8.1 General
		14.8.2 Assessment Level
		14.8.3 Loading Time History
		14.8.4 Material Properties
		14.8.5 Stress Analysis Results
		14.8.6 Assessment Results
		14.8.7 Remaining Life Assessment
		14.8.8 Remediation Methods
		14.8.9 In-Service Monitoring
	14.9 Nomenclature
	14.10 References
	14.11  Tables
	14.12  Figures
Annex 14A  – Technical Basis And Validation – Assessment Of Fatigue Damage
	14A.1 Technical Basis and Validation
	14A.2 References
Annex 14B  – Material Properties For Fatigue Analysis
	14B.1 Smooth Bar Fatigue Curves
		14B.1.1 Fatigue Curves
		14B.1.2 Fatigue Curve Models
		14B.1.3 Computation of Allowable Cycles
	14B.2 Uniform Material Law
	14B.3 Welded Joint Fatigue Curves
		14B.3.1 Fatigue Curve Models
		14B.3.2 Computation of Allowable Cycles
	14B.4 Nomenclature
	14B.5 References
	14B.6  Tables
	14B.7  Figures
Annex 14C  – Plasticity Correction And Cycle Counting For Fatigue Analysis
	14C.1 Introduction
		14C.1.1  Cycle Counting
		14C.1.2  Plasticity Correction
		14C.1.3  Definitions
		14C.1.4  Histogram Development
	14C.2  Plasticity Correction
		14C.2.1   Uniaxial Plasticity Correction
		14C.2.2   Multiaxial Plasticity Correction
			14C.2.2.1 For multiaxial  stress states (either proportional or non-proportional), the general, incremental, multiaxial Neuber’s rule is used to estimate the  desired elastic-plastic stress and strain components,  and  at times , , from the  purely el...
			14C.2.2.2 If a Level 2 Method A assessment is being performed, cycle count the elastic stress-based loading history first using the Wang Brown Algorithm in Paragraph 14C.4.1 and then refer to Part 14, Paragraph 14.4.3.2.2 for plasticity correction aft...
			14C.2.2.3 A visual representation of the Neuber plasticity correction is shown in Figure 14C.5.  A flowchart for the multiaxial Neuber’s rule plasticity correction procedure is shown in Figure 14C.6.  A step-by-step procedure for plasticity correction...
	14C.3  Uniaxial Cycle Counting
		14C.3.1  Rainflow Cycle Counting – With Reordering
			14C.3.1.1 The Rainflow Cycle Counting (RCC) method (ASTM Standard No. E1049 three point method) is recommended to determine the time points representing individual cycles for situations where the variation of stress or strain over time can be represen...
			14C.3.1.2 A step-by-step procedure for the RCC algorithm is shown below for an arbitrary loading history (stress or strain).  The flowchart associated with this procedure is shown in Figure 14C.8. An example that demonstrates the use of this algorithm...
			14C.3.1.3 Using the recorded cycle count data obtained by using the RCC method, a fatigue damage assessment is performed in accordance with Part 14, Paragraph 14.4.3.4.2 for a Level 2 Method C assessment.  Additional uniaxial damage assessment models ...
		14C.3.2  Additional Rainflow Cycle Counting – Without Reordering
	14C.4  Multiaxial Cycle Counting
		14C.4.1  Wang-Brown Cycle Counting
			14C.4.1.1 The Wang-Brown Cycle Counting (WBCC) method is a six-dimensional, multiaxial Rainflow count that is recommended to determine the time points representing individual half cycles for situations where the variation in time of loading, stress, o...
			14C.4.1.2 The WBCC algorithm takes as input a sequence of  loading history values indexed by .  For each value of , the stress and/or the strain may be specified, depending on whether a strain-based or stress-based approach is desired.  The WBCC algor...
			14C.4.1.3 Each point on a path may correspond to one of the original loading history points, or it may be an interpolated point that lies between two of those existing points.  If the  point corresponds exactly to an original point in the loading hist...
			14C.4.1.4 The components of the stress or strain tensor of the interpolated point can be determined from the value of  by linearly interpolating between the stress or strain components at  and .  For instance, the value of any stress component  at any...
			14C.4.1.5 A step-by-step procedure for performing Wang-Brown cycle counting, which results in a list of ordered indices  for each path  is presented below, and a basic flowchart for this algorithm is provided in Figure 14C.9.  The steps presented belo...
			14C.4.1.6 Using the recorded cycle count data (loading ranges) obtained by using the WBCC method outlined above, the fatigue damage is calculated in accordance with a Level 2 Method A (stress-based) in Part 14, Paragraph 14.4.3.2.2 or Level 2 Method B...
			14C.4.1.7 As an example, the Brown-Miller damage parameters,  and , are calculated as follows, assuming the loading values were based on strain.
		14C.4.2  Critical Plane Cycle Counting
			14C.4.2.1 The Critical Plane Cycle Counting (CPCC) method considers multiple candidate planes and defines the plane that experiences the maximum damage as the critical plane.  CPCC is recommended to determine the time points representing individual ha...
			14C.4.2.2 CPCC involves sequentially choosing a number of candidate planes by rotating the original (unprimed) coordinate system to a new orientation (using primed coordinates) as shown in Figure 14C.11.  The normal and shear stresses and strains are ...
			14C.4.2.3 A step-by-step procedure for CPCC is shown below.  An example that demonstrates the use of this algorithm is included in WRC Bulletin 550 [1].
	14C.5 Nomenclature
	14C.6 References
	14C.7  Figures