4.1 The COPVs covered in this guide consist of a metallic liner overwrapped with high-strength fibers embedded in polymeric matrix resin (typically a thermoset) (Fig. 1). Metallic liners may be spun-formed from a deep drawn/extruded monolithic blank or may be fabricated by welding formed components. Designers often seek to minimize the liner thickness in the interest of weight reduction. COPV liner materials used can be aluminum alloys, titanium alloys, nickel-chromium alloys, and stainless steels, impermeable polymer liner such as high density polyethylene, or integrated composite materials. Fiber materials can be carbon, aramid, glass, PBO, metals, or hybrids (two or more types of fibers). Matrix resins include epoxies, cyanate esters, polyurethanes, phenolic resins, polyimides (including bismaleimides), polyamides, and other high performance polymers. Common bond line adhesives are FM-73, urethane, West 105, and Epon 862 with thicknesses ranging from 0.13 mm (0.005 in.) to 0.38 mm (0.015 in.). Metallic liner and composite overwrap materials requirements are found in ANSI/AIAA S-080 and ANSI/AIAA S-081, respectively.NOTE 6: When carbon fiber is used, galvanic protection should be provided for the metallic liner using a physical barrier such as glass cloth in a resin matrix, or similarly, a bond line adhesive.NOTE 7: Per the discretion of the cognizant engineering organization, composite materials not developed and qualified in accordance with the guidelines in MIL-HDBK-17, Volumes 1 and 3 should have an approved material usage agreement.FIG. 1 Typical Carbon Fiber Reinforced COPVs (NASA)4.2 The as-wound COPV is then cured and an autofrettage/proof cycle is performed to evaluate performance and increase fatigue characteristics.4.3 The strong drive to reduce weight and spatial needs in aerospace applications has pushed designers to adopt COPVs constructed with high modulus carbon fibers embedded in an epoxy matrix. Unfortunately, high modulus fibers are weak in shear and therefore highly susceptible to fracture caused by mechanical damage. Mechanical damage to the overwrap can leave no visible indication on the composite surface, yet produce subsurface damage.NOTE 8: The impact damage tolerance of the composite overwrap will depend on the size and shape of the vessel, composite thickness (number of plies), and thickness of the composite overwrap relative to that of the liner.4.4 Per MIL-HDBK-340 and ANSI/AIAA S-081, the primary intended function of COPVs as discussed in this guide will be to store pressurized gases and fluids where one or more of the following apply:4.4.1 Contains stored energy of 19 310 J (14 240 ft-lbf) or greater based on adiabatic expansion of a perfect gas.4.4.2 Contains a gas or liquid that would endanger personnel or equipment or create a mishap (accident) if released.4.4.3 Experiences a design limit pressure greater than 690 kPa (100 psi).4.5 According to NASA-STD-(I)-5019, COPVs shall comply with the latest revision of ANSI/AIAA S-081. The following requirements also apply when implementing S-081:4.5.1 Maximum Design Pressure (MDP) shall be substituted for all references to Maximum Expected Operating Pressure (MEOP) in S-081.4.5.2 COPVs shall have a minimum of 0.999 probability of no stress rupture failure of the composite shell during the service life.NOTE 9: For other aerospace applications, the cognizant engineering organization should select the appropriate probability of survival, for example, 0.99, 0.999, 0.9999, etc., depending on the anticipated failure mode, damage tolerance, safety factor, or consequence of failure, or a combination thereof. For example, a probability of survival of 0.99 means that on average, 1 in 100 COPVs will fail. COPVs exhibiting catastrophic failure modes (BBL composite shell stress rupture versus LBB liner leak), lower damage tolerance (cylindrical versus spherical vessels), lower safety factor, and high consequence of failure will be subject to more rigorous NDT.4.6 Application of the NDT procedures discussed in this guide is intended to reduce the likelihood of composite overwrap failure, commonly denoted “burst before leak” (BBL), characterized by catastrophic rupture of the overwrap and significant energy release, thus mitigating or eliminating the attendant risks associated with loss of pressurized commodity, and possibly ground support personnel, crew, or mission.4.6.1 NDT is done on fracture-critical parts such as COPVs to establish that a low probability of preexisting flaws is present in the hardware.4.6.2 Following the discretion of the cognizant engineering organization, NDT for fracture control of COPVs should follow additional general and detailed guidance described in MIL-HDBK-6870, NASA-STD-(I)-5019, MSFC-RQMT-3479, or ECSS-E-30-01A, or a combination thereof, not covered in this guide.4.6.3 Hardware that is proof tested as part of its acceptance (that is, not screening for specific flaws) should receive post-proof NDT at critical welds and other critical locations.4.7 Discontinuity Types—Specific discontinuity types are associated with the particular processing, fabrication, and service history of the COPV. Metallic liners can have cracks, buckles, leaks, and a variety of weld discontinuities (see 4.6 in Guide E2982). Non-bonding flaws (voids) between the liner and composite overwrap can also occur. Similarly, the composite overwrap can have preexisting manufacturing flaws introduced during fabrication, and damage caused by autofrettage or proof testing before being placed into service. Once in service, additional damage can be incurred due to low velocity or micrometeorite orbital debris impacts, cuts/scratches/abrasion, fire, exposure to aerospace media, loading stresses, thermal cycling, physical aging, oxidative degradation, weathering, and space environment effects (exposure to atomic oxygen and ionizing radiation). These factors will lead to complex damage states in the overwrap that can be visible or invisible, macroscopic or microscopic. These damage states can be characterized by the presence of porosity, depressions, blisters, wrinkling, erosion, chemical modification, foreign object debris (inclusions), tow termination errors, tow slippage, misaligned tows, distorted tows, matrix crazing, matrix cracking, matrix-rich regions, under and over-cure of the matrix, fiber-rich regions, fiber-matrix debonding, fiber pull-out, fiber splitting, fiber breakage, bridging, liner/overwrap debonding, and delamination. Often these discontinuities can placed into four major categories: (1) manufacturing; (2) scratch/scuff/abrasion; (3) mechanical damage; and (4) discoloration.4.8 Effect of Defect—The effect of a given composite flaw type or size (“effect of defect”) is difficult to determine unless test specimens or articles with known types and sizes of flaws are tested to failure. Given this potential uncertainty, detection of a flaw is not necessarily grounds for rejection (that is, a defect) unless the effect of defect has been demonstrated. Even the detection of a given flaw type and size can be in doubt unless physical reference specimens with known flaw types and sizes undergo evaluation using the NDT method of choice. The suitability of various NDT methods for detecting commonly occurring composite flaw types is given in Table 1 in Guide E2533.4.9 Acceptance Criteria—Determination about whether a COPV meets acceptance criteria and is suitable for aerospace service should be made by the cognizant engineering organization. When examinations are performed in accordance with this guide, the engineering drawing, specification, purchase order, or contract should indicate the acceptance criteria.4.9.1 Accept/reject criteria should consist of a listing of the expected kinds of imperfections and the rejection level for each.4.9.2 The classification of the articles under test into zones for various accept/reject criteria should be determined from contractual documents.4.9.3 Rejection of COPVs—If the type, size, or quantities of defects are found to be outside the allowable limits specified by the drawing, purchase order, or contract, the composite article should be separated from acceptable articles, appropriately identified as discrepant, and submitted for material review by the cognizant engineering organization, and given one of the following dispositions: (1) acceptable as is, (2) subject to further rework or repair to make the materials or component acceptable, or (3) scrapped (made permanently unusable) when required by contractual documents.4.9.4 Acceptance criteria and interpretation of results should be defined in requirements documents prior to performing the examination. Advance agreement should be reached between the purchaser and supplier regarding the interpretation of the results of the examinations. All discontinuities having signals that exceed the rejection level as defined by the process requirements documents should be rejected unless it is determined from the part drawing that the rejectable discontinuities will not remain in the finished part.4.10 Certification of COPVs—ANSI/AIAA S-081 defines the approach for design, analysis, and certification of COPVs. More specifically, the COPV should exhibit a leak before burst (LBB) failure mode or should possess adequate damage tolerance life (safe-life), or both, depending on criticality and whether the application is for a hazardous or nonhazardous fluid. Consequently, the NDT method should detect any discontinuity that can cause burst at expected operating conditions during the life of the COPV. The Damage-Tolerance Life requires that any discontinuity present in the liner will not grow to failure during the expected life of the COPV. Fracture mechanics assessments of flaw growth are the typical method of setting limits on the sizes of discontinuities that can safely exist. This establishes the defect criteria: all discontinuities equal to or larger than the minimum size or have J-integral or other applicable fracture mechanics based criteria that will result in failure of the vessel within the expected service life are classified as defects and should be addressed by the cognizant engineering organization.4.10.1 Design Requirements—COPV design requirements related to the composite overwrap are given in ANSI/AIAA S-081. The key requirement is the stipulation that the COPV shall exhibit a LBB failure mode or shall possess adequate damage tolerance life (safe-life), or both, depending on criticality and application. The overwrap design shall be such that, if the liner develops a leak, the composite will allow the leaking fluid (liquid or gas) to pass through it so that there will be no risk of composite rupture. However, under use conditions of prolonged, elevated stress, assurance should be made that the COPV overwrap will also not fail by stress (creep) rupture, as verified by theoretical analysis of experimental data (determination of risk reliability factors) or by test (coupons or flight hardware).4.11 Probability of Detection (POD)—Detailed instruction for assessing the reliability of NDT data using POD of a complex structure such as a COPV is beyond the scope of this guide. Therefore, only general guidance is provided. More detailed instruction for assessing the capability of an NDT method in terms of the POD as a function of flaw size, a, can be found in MIL-HDBK-1823. The statistical precision of the estimated POD(a) function (Fig. 2) depends on the number of inspection sites with targets, the size of the targets at the inspection sites, and the basic nature of the examination result (hit/miss or magnitude of signal response).FIG. 2 Probability of Detection as a Function of Flaw SizeNOTE 1: POD(a), showing the location of the smallest detectable flaw and a90 (left). POD(a) with confidence bounds added and showing the location of a90/95 (right).4.11.1 Given that a90/95 has become a de facto design criterion, it is more important to estimate the 90th percentile of the POD(a) function more precisely than lower parts of the curve. This can be accomplished by placing more targets in the region of the a90 value but with a range of sizes so the entire curve can still be estimated.NOTE 10: a90/95 for a composite overwrap and generation of a POD(a) function is predicated on the assumption that effect of defect has been demonstrated and is known for a specific composite flaw type and size, and that detection of a flaw of that same type and size is grounds for rejection, that is, the flaw is a rejectable defect.4.11.2 To provide reasonable precision in the estimates of the POD(a) function, experience suggests that the specimen test set contain at least 60 targeted sites if the system provides only a binary, hit/miss response and at least 40 targeted sites if the system provides a quantitative target response, â. These numbers are minimums.4.11.3 For purposes of POD studies, the NDT method should be classified into one of three categories:4.11.3.1 Those which produce only qualitative information as to the presence or absence of a flaw, that is, hit/miss data.4.11.3.2 Those which also provide some quantitative measure of the size of the target (for example, flaw or crack), that is, â versus a data.4.11.3.3 Those which produce visual images of the target and its surroundings.1.1 This guide discusses current and potential nondestructive testing (NDT) procedures for finding indications of discontinuities and accumulated damage in the composite overwrap of filament wound pressure vessels, also known as composite overwrapped pressure vessels (COPVs). In general, these vessels have metallic liner thicknesses less than 2.3 mm (0.090 in.), and fiber loadings in the composite overwrap greater than 60 % by weight. In COPVs, the composite overwrap thickness will be of the order of 2.0 mm (0.080 in.) for smaller vessels and up to 20 mm (0.80 in.) for larger ones.1.2 This guide focuses on COPVs with nonload-sharing metallic liners used at ambient temperature, which most closely represents a Compressed Gas Association (CGA) Type III metal-lined composite tank. However, it also has relevance to (1) monolithic metallic pressure vessels (PVs) (CGA Type I), (2) metal-lined hoop-wrapped COPVs (CGA Type II), (3) plastic-lined composite pressure vessels (CPVs) with a nonload-sharing liner (CGA Type IV), and (4) an all-composite, linerless COPV (undefined Type). This guide also has relevance to COPVs used at cryogenic temperatures.1.3 The vessels covered by this guide are used in aerospace applications; therefore, the inspection requirements for discontinuities and inspection points will in general be different and more stringent than for vessels used in non aerospace applications.1.4 This guide applies to (1) low pressure COPVs used for storing aerospace media at maximum allowable working pressures (MAWPs) up to 3.5 MPa (500 psia) and volumes up to 2 L (70 ft3), and (2) high pressure COPVs used for storing compressed gases at MAWPs up to 70 MPa (10 000 psia) and volumes down to 8 L (500 in.3). Internal vacuum storage or exposure is not considered appropriate for any vessel size.NOTE 1: Some vessels are evacuated during filling operations, requiring the tank to withstand external (atmospheric) pressure, while other vessels may either contain or be immersed in cryogenic fluids, or both, requiring the tanks to withstand any potentially deleterious effects of differential thermal contraction.1.5 The composite overwraps under consideration include, but are not limited to, ones made from various polymer matrix resins (for example, epoxies, cyanate esters, polyurethanes, phenolic resins, polyimides (including bismaleimides), and polyamides) with continuous fiber reinforcement (for example, carbon, aramid, glass, or poly-(phenylenebenzobisoxazole) (PBO)). The metallic liners under consideration include, but are not limited to, aluminum alloys, titanium alloys, nickel-chromium alloys, and stainless steels.1.6 This guide describes the application of established NDT methods; namely, Acoustic Emission (AE, Section 7), Eddy Current Testing (ET, Section 8), Laser Shearography (Section 9), Radiographic Testing (RT, Section 10), Infrared Thermography (IRT, Section 11), Ultrasonic Testing (UT, Section 12), and Visual Testing (VT, Section 13). These methods can be used by cognizant engineering organizations for detecting and evaluating flaws, defects, and accumulated damage in the composite overwrap of new and in-service COPVs.NOTE 2: Although visual testing is discussed and required by current range standards, emphasis is placed on complementary NDT procedures that are sensitive to detecting flaws, defects, and damage that leave no visible indication on the COPV surface.NOTE 3: In aerospace applications, a high priority is placed on light weight material, while in commercial applications, weight is typically sacrificed to obtain increased robustness. Accordingly, the need to detect damage below the visual damage threshold is more important in aerospace vessels.NOTE 4: Currently, no determination of residual strength can be made by any NDT method.1.7 All methods discussed in this guide (AE, ET, shearography, RT, IRT, UT, and VT) are performed on the composite overwrap after overwrapping and structural cure. For NDT procedures for detecting discontinuities in thin-walled metallic liners in filament wound pressure vessels, or in the bare metallic liner before overwrapping; namely, AE, ET, laser profilometry, leak testing (LT), penetrant testing (PT), and RT; consult Guide E2982.1.8 In the case of COPVs which are impact damage sensitive and require implementation of a damage control plan, emphasis is placed on NDT methods that are sensitive to detecting damage in the composite overwrap caused by impacts at energy levels and which may or may not leave any visible indication on the COPV composite surface.1.9 This guide does not specify accept-reject criteria (4.9) to be used in procurement or used as a means for approving filament wound pressure vessels for service. Any acceptance criteria specified are given solely for purposes of refinement and further elaboration of the procedures described in this guide. Project or original equipment manufacturer (OEM) specific accept/reject criteria should be used when available and take precedence over any acceptance criteria contained in this document. If no accept/reject criteria are available, any NDT method discussed in this guide that identifies broken fibers should require disposition by the cognizant engineering organization.1.10 This guide references both established ASTM methods that have a foundation of experience and that yield a numerical result, and newer procedures that have yet to be validated and are better categorized as qualitative guidelines and practices. The latter are included to promote research and later elaboration in this guide as methods of the former type.1.11 To ensure proper use of the referenced standard documents, there are recognized NDT specialists that are certified according to industry and company NDT specifications. It is recommended that an NDT specialist be a part of any composite component design, quality assurance, in-service maintenance, or damage examination.1.12 Units—The values stated in SI units are to be regarded as standard. The English units given in parentheses are provided for information only.1.13 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Some specific hazards statements are given in Section 7 on Hazards.1.14 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1 This practice facilitates the selection and application of an insulation system for use at service temperatures between − 30 and + 107°C (−22 and + 225°F). Although the successful installation of spray-applied PUR/PIR is influenced by many factors, this practice treats those four areas found to be of major importance:(1) Substrate preparation,(2) Substrate priming,(3) Insulation application, and(4) Protective coatings.4.2 Abrasive blasting, primer application, spray application of the insulation, and protective coating application each contribute their unique health and safety hazards to the job site and will be dealt with in more detail under their respective headings.1.1 This practice concerns itself with the substrate preparation and priming, the selection of the rigid cellular polyurethane system, and the protective insulation coatings for outdoor service equipment.NOTE 1: For the purpose of this practice, polyurethane is defined to mean either polyurethane or polyisocyanurate and is hereafter referred to as “PUR/PIR.”1.2 The values given in inch-pound are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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4.1 Neutron radiation effects are considered in the design of light-water moderated nuclear power reactors. Changes in system operating parameters may be made throughout the service life of the reactor to account for these effects. A surveillance program is used to measure changes in the properties of actual vessel materials due to the irradiation environment. This practice describes the criteria that should be considered in evaluating surveillance program test capsules.4.2 Prior to the first issue date of this standard, the design of surveillance programs and the testing of surveillance capsules were both covered in a single standard, Practice E185. Between its provisional adoption in 1961 and its replacement linked to this standard, Practice E185 was revised many times (1966, 1970, 1973, 1979, 1982, 1993 and 1998). Therefore, capsules from surveillance programs that were designed and implemented under early versions of the standard were often tested after substantial changes to the standard had been adopted. For clarity, the standard practice for surveillance programs has been divided into the new Practice E185 that covers the design of new surveillance programs and this standard practice that covers the testing and evaluation of surveillance capsules. Modifications to the standard test program and supplemental tests are described in Guide E636.4.3 This practice is intended to cover testing and evaluation of all light-water moderated reactor pressure vessel surveillance capsules. The practice is applicable to testing of capsules from surveillance programs designed and implemented under all previous versions of Practice E185.4.4 The radiation-induced changes in the properties of the reactor pressure vessel are generally monitored by measuring the index temperatures, the upper-shelf energy and the tensile properties of specimens from the surveillance program capsules. The significance of these radiation-induced changes is described in Practice E185.4.5 Alternative methods exist for testing surveillance capsule materials. Some supplemental and alternative testing methods are available as indicated in Guide E636. Direct measurement of the fracture toughness is also feasible using the To Reference Temperature method defined in Test Method E1921 or J-integral techniques defined in Test Method E1820. Additionally, hardness testing can be used to supplement standard methods as a means of monitoring the irradiation response of the materials.4.6 Practice E853 describes a methodology that may be used in the analysis and interpretation of neutron dosimetry data and the determination of neutron fluence. Regulators or other sources may describe different methods.4.7 Guide E900 describes a method for predicting the TTS. Regulators or other sources may describe different methods for predicting TTS.4.8 Guide E509 provides direction for development of a procedure for conducting an in-service thermal anneal of a light-water cooled nuclear reactor vessel and demonstrating the effectiveness of the procedure including a post-annealing vessel radiation surveillance program.1.1 This practice covers the evaluation of test specimens and dosimetry from light water moderated nuclear power reactor pressure vessel surveillance capsules.1.2 Additionally, this practice provides guidance on reassessing withdrawal schedule for design life and operation beyond design life.1.3 This practice is one of a series of standard practices that outline the surveillance program required for nuclear reactor pressure vessels. The surveillance program monitors the irradiation-induced changes in the ferritic steels that comprise the beltline of a light-water moderated nuclear reactor pressure vessel.1.4 This practice along with its companion surveillance program practice, Practice E185, is intended for application in monitoring the properties of beltline materials in any light-water moderated nuclear reactor.21.5 Modifications to the standard test program and supplemental tests are described in Guide E636.1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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This specification covers 9% nickel-alloy steel plates produced by the direct-quenching process. The plates are intended primarily for use in welded pressure vessels. The steel shall be killed and shall conform to the fine austenitic grain size requirement specified. The steel shall conform to the chemical requirements specified. Tension test and impact test shall be made to conform to the requirements specified.1.1 This specification covers 9 % nickel-alloy steel plates produced by the direct-quenching process. The plates are intended primarily for use in welded pressure vessels.1.2 The direct-quenching process consists of quenching the plates directly after rolling, without permitting the plates to cool below the critical temperature prior to initiation of the quenching operation, and subsequently tempering the plates (see Appendix X1). (Note: The direct-quenching process differs from the “conventional” process in which the plates are permitted to cool to a temperature significantly below the critical temperature, usually to ambient temperature, prior to reheating to a temperature above the upper critical temperature, then quenching, and subsequently tempering.)1.3 If the plates are subjected to warm forming, the temperature shall not exceed 950°F [510°C].1.4 The maximum nominal thickness of plates furnished under this specification shall not exceed 2 in. [50 mm].1.5 This material is susceptible to magnetization. Use of magnets in handling after heat treatment should be avoided if residual magnetism would be detrimental to subsequent fabrication or service.1.6 The values stated in either inch-pound or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 The purpose of this practice is to provide a procedure for locating, detecting and estimating the relevance of longitudinally oriented crack-like discontinuities which have been previously indicated by AE examination.5.2 This practice may be used for a pressure vessel that is situated in such a way as to limit access to the vessel's wall. Typical examples include tube trailers and gas tube railroad cars. Since the pressure vessels are stacked horizontally in a frame, with limited space between them, the circumferential location of a discontinuity may be a distance away from the search unit (several skip distances).5.3 This practice has been shown to be effective for cylinders between 9 in. (229 mm) and 24 in. (610 mm) in diameter and wall thicknesses between 1/4 in. (6.4 mm) to 1 in. (26 mm) with discontinuities that are oriented longitudinally in pressure vessel sidewall.5.4 To reliably detect discontinuities by the procedure in this practice, a significant part of the reflecting surface must be transverse to the beam direction.5.5 Evaluation of possible discontinuity in the end faces indicated by AE is not covered by this practice.1.1 This practice describes a contact angle-beam shear wave ultrasonic technique to detect and locate the circumferential position of longitudinally oriented discontinuities and to compare the amplitude of the indication from such discontinuities to that of a specified reference notch. This practice does not address examination of the vessel ends. The basic principles of contact angle-beam examination can be found in Practice E587. Application to pipe and tubing, including the use of notches for standardization, is described in Practice E213.1.2 This practice is appropriate for the ultrasonic examination of cylindrical sections of gas-filled, seamless, steel pressure vessels such as those used for the storage and transportation of pressurized gasses. It is applicable to both isolated vessels and those in assemblies.1.3 The practice is intended to be used following an Acoustic Emission (AE) examination of stacked seamless gaseous pressure vessels (with limited surface scanning area) described in Test Method E1419.1.4 This practice does not establish acceptance criteria. These are determined by the reference notch dimensions, which must be specified by the using parties.NOTE 1: Background information relating to the technical requirements of this practice can be found in the references sited in Test Method E1419, Appendix X1.1.5 Dimensional values stated in inch-pound units are regarded as standard; SI equivalents, in parentheses may be approximate.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 Due to safety considerations, the Compressed Gas Association (CGA) and others have produced guidelines which address in-service inspection of NGV fuel containers (see 2.2 – 2.4). AE examination is listed as an alternative to the minimum three-year visual examination which generally requires that the container be removed from the vehicle to expose the entire container surface. The AE method allows “in-situ” examination of the container.5.1.1 Slow-fill pressurization must proceed at flow rates that do not produce background noise from flow of the pressurizing medium. Acoustic emission data are recorded throughout a pressurization range (that is, 50 % to 100 % of AE examination pressure).5.1.2 Fast-fill pressurization can be used if hold periods are provided. Acoustic emission data are recorded only during the hold periods.NOTE 1: Fast-fill pressurization is less appropriate for carbon (or graphite) composites due to the lower sensitivity of carbon fibers to stress rupture compared to other fibers.5.1.3 Background noise above the threshold will contaminate the AE data and render them useless. Users must be aware of the following common causes of background noise: high fill rate (measurable flow noise); mechanical contact with the vessel by objects; electromagnetic interference (EMI) and radio frequency interference (RFI) from nearby broadcasting facilities and from other sources; leaks at pipe or hose connections and airborne particles, insects, rain and snow. This practice should not be used if background noise cannot be eliminated or controlled.5.2 Sensitivity is influenced by factors that affect elastic wave propagation, sensor coupling and signal processor settings.5.3 It is possible to measure AE from AE sources that cannot be verified by other NDE methods.1.1 This practice provides guidelines for acoustic emission (AE) examination of filament-wound composite pressure vessels, for example, the type used for fuel tanks in vehicles which use natural gas fuel.1.2 This practice requires pressurization to a level equal to or greater than what is encountered in normal use. The tanks' pressurization history must be known in order to use this practice. Pressurization medium may be gas or liquid.1.3 This practice is limited to vessels designed for less than 275 bar [4,000 psi] maximum allowable working pressure and water volume less than 1 m3 or 1000 L [35.4 ft3].1.4 AE measurements are used to detect emission sources. Other nondestructive examination (NDE) methods may be used to gain additional insight into the emission source. Procedures for other NDE methods are beyond the scope of this practice.1.5 This practice applies to examination of new and in-service, Type II, filament-wound composite pressure vessels.1.6 This practice applies to examinations conducted at ambient temperatures above 20°C [70°F]. This practice may be used at ambient temperatures below 20°C [70°F] if provision has been made to fill to the tank's rated pressure at 20°C [70°F]. Also that the test temperature must not exceed the glass transition temperature of the matrix material.1.7 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8.

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This specification covers chromium, chromium-nickel, and chromium-manganese-nickel stainless steel plate, sheet, and strip for pressure vessels and for general applications. The steel shall conform to the requirements as to chemical composition specified. The material shall conform to the mechanical properties specified.1.1 This specification2 covers chromium, chromium-nickel, and chromium-manganese-nickel stainless steel plate, sheet, and strip for pressure vessels and for general applications including architectural, building, construction, and aesthetic applications.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 This specification is expressed in both inch-pound and SI units. However, unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished in inch-pound units.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 646元 加购物车

AbstractASTM A592/A592M-04 covers the standard specification for high-strength quenched and tempered low-alloy steel forged fittings and parts used for pressure vessels. The steel shall be made by a melting process and shall be fully killed and fine grained. After forging and before reheating, the forgings shall be cooled to provide substantially complete transformation of austenite. Samples for mechanical test specimens shall be removed after the quenching and tempering heat treatment. The test specimens may be machined from a production forging or from special forged blocks suitably worked and heat treated with the production forgings. Such special blocks shall be obtained from an ingot, slab, or billet from the same heat as the forgings they represent and shall be reduced by forging in a manner similar to that for the products to be represented. The specimens shall undergo tension and Charpy V-notch impact tests.1.1 This specification2 covers high-strength quenched and tempered low-alloy steel forged parts for pressure vessels. The maximum thickness of forgings under this specification shall be 11/2 in. [38 mm] for Grade A, and 4 in. [100 mm] for Grades E and F.NOTE 1: These grades are similar to corresponding grades in Specification A517/A517M.1.2 Although no provision is made for supplementary requirements in this standard, the supplementary requirements in Specification A788/A788M may be considered by the purchaser.1.3 Welding technique is of fundamental importance and it is presupposed that welding procedures will be in accordance with approved methods for the class of material used.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.5 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound units.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 加购物车