定价： 345元 / 折扣价： 294 元

4.1 The AU method should be considered for vessels that are proven to be free of major flaws or discontinuities as determined by conventional techniques. The AU method may be used for detecting major flaws if other methods are deemed impractical. It is important to use methods such as immersion pulse-echo ultrasonics (Practice E1001) and acoustic emission (Practice E1067) to ascertain the presence of major flaws before proceeding with AU.4.2 The AU method is intended almost exclusively for materials characterization by assessing the collective effects of dispersed defects and subcritical flaw populations. These are material aberrations that influence AU measurements and also underlie mechanical property variations, dynamic load response, and impact and fracture resistance.74.3 The AU method can be used to evaluate laminate quality using access to only one surface, the usual constraint imposed by closed pressure vessels. For best results, the AU probes must be fixtured to maintain the probe orientation at normal incidence to the curved surface of the vessel. Given these constraints, this practice describes a procedure for automated AU scanning using water squirters to assess the serviceability and reliability of filament-wound pressure vessels.81.1 This practice covers a procedure for acousto-ultrasonic (AU) assessment of filament-wound pressure vessels. Guidelines are given for the detection of defect states and flaw populations that arise during materials processing or manufacturing or upon exposure to aggressive service environments. Although this practice describes an automated scanning mode, similar results can be obtained with a manual scanning mode.1.2 This procedure recommends technical details and rules for the reliable and reproducible AU detection of defect states and flaw populations. The AU procedure described herein can be a basis for assessing the serviceability of filament-wound pressure vessels.1.3 The objective of the AU method is primarily the assessment of defect states and diffuse flaw populations that influence the mechanical strength and ultimate reliability of filament-wound pressure vessels. The AU approach and probe configuration are designed specifically to determine composite properties in lateral rather than through-the-thickness directions.21.4 The AU method is not for flaw detection in the conventional sense. The AU method is most useful for materials characterization, as explained in Guide E1495, which gives the rationale and basic technology for the AU method. Flaws and discontinuities such as large voids, disbonds, or extended lack of contact of interfaces can be found by other nondestructive examination (NDE) methods such as immersion pulse-echo ultrasonics.1.5 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this practice.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.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 These tolerances may be used as a guide in purchaser/supplier disputes, or to assist in assigning nominal values for linear density and twist. The tolerances listed for each property represent the maximum variations deemed acceptable in the trade.1.1 These tolerances cover first-quality, manufactured, organic-base filament single yarns (namely, bright, semi-dull, dull, solution-dyed, bleached, unbleached, etc.) regardless of the package type. These tolerances cover permissible variations in linear density, tenacity, elongation, twist, and commercial weight.1.1.1 These tolerances do not apply to rubber yarns, spandex yarns, metal-covered yarns, nor to bulk yarns since test methods for these types of yarn are not available. These tolerances do not apply to industrial filament yarns.NOTE 1: Tolerances for inorganic glass yarns are given in Specifications and Methods D578/D578M.1.2 This standard covers only tolerances. It does not cover specifications or quality levels, for yarns to be used for any purpose. Specifications for specific properties are subject to agreement by the purchaser and the supplier.NOTE 2: While the tolerances specified may be applied to yarn taken from fabric, the properties of such yarns will likely differ from the original level.1.3 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.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 The procedures for the determination of properties of single-filament bead wire made from steel are considered satisfactory for acceptance testing of commercial shipments of this product because the procedures are the best available and have been used extensively in the trade.5.1.1 In case of a dispute arising from differences in reported test results when using these test methods for acceptance testing of commercial shipments, the purchaser and supplier should conduct comparative test to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens which are as homogeneous as possible and which are from a lot of material of the type in question. The test specimens then should be randomly assigned in equal number to each laboratory for testing. The average results from the two laboratories should be compared using Student's t-test for unpaired data and an acceptable probability level chosen by the two parties before testing is begun. If a bias is found, either its cause must be determined and corrected or the purchaser and the supplier must agree to interpret future test results with consideration to the known bias.1.1 These test methods cover testing of single-filament steel wires that are components of tire beads used in the manufacture of pneumatic tires. By agreement, these test methods may be applied to similar filaments used for reinforcing other rubber products.1.2 These test methods describe test procedures only and do not establish specifications and tolerances.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 These test methods cover the determination of the mechanical properties listed below:  Property   Section   Breaking Force (Strength)  7 – 13  Yield Strength  7 – 13  Elongation  7 – 13  Torsion Resistance 14 – 20  Diameter (Gage) 21 – 271.5 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.

定价： 0元 / 折扣价： 0 元

5.1 Option 1 of this test method is for the determination of the degree of filament yarn entanglement, as measured instrumentally. It is used for acceptance testing of commercial shipments; however, caution is advised because information on between-laboratory precision is lacking. Comparative tests, as directed in 5.1.1, may be advisable.5.1.1 If there are differences of practical significance between the reported test results for two or more laboratories, comparative tests should be performed by those laboratories to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, samples used for each comparative test should be as homogeneous as possible, drawn from the same lot of material as the samples that results in disparate results during initial testing, and randomly assigned in equal numbers to each laboratory. Other fabrics with established test values may be used for this purpose. The test results from the laboratories involved should be compared statistically. If a bias is found, either its cause must be found and corrected or future test results must be adjusted in consideration of the known bias.5.2 Option 2 for this test method is intended for use when the supply of yarn is limited.5.3 The instrumental option of this test method, Option 1, is based on the total randomization of the entanglements in the yarn; therefore, the distance measured between the point of insertion of a pin in the middle of the yarn and the point at which an entanglement is encountered, by movement of the yarn or the pin until it is stopped at a preset level of force, is representative of the distance between two entanglements at some location in the yarn.5.4 Entanglements are used frequently instead of twist to ensure the integrity of filament yarns. Such entanglements generally give somewhat less protection during weaving or knitting than twist, but with proper care, will perform quite satisfactorily.1.1 This test method covers two options for the measurement of entanglements in filament yarns using needle insertion options for instrument (Option 1) (Option 2) techniques.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 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.1.3 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.

定价： 590元 / 折扣价： 502 元 加购物车

This specification covers cylindrical corrosion-resistant tanks made of commercial-grade glass-fiber-reinforced polyester or vinylester thermoset resin fabricated by filament winding for above-ground vertical installation, to contain aggressive chemicals at atmospheric pressure as classified herein. This specification does not address the design of vessels intended for pressure above atmospheric, vacuum conditions, except as classified herein, or vessels intended for use with liquids heated above their flash points. Included are requirements for materials, properties, design, construction, dimensions, tolerances, workmanship, and appearance.1.1 This specification covers cylindrical tanks fabricated by filament winding for above-ground vertical installation, to contain aggressive chemicals at atmospheric pressure as classified herein, and made of a commercial-grade polyester or vinylester resin. Included are requirements for materials, properties, design, construction, dimensions, tolerances, workmanship, and appearance.1.2 This specification does not cover the design of vessels intended for pressure above atmospheric or under vacuum conditions, except as classified herein, or vessels intended for use with liquids heated above their flash points.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.4 Special design consideration shall be given to tanks subject to environmental and/or mechanical forces such as seismic, wind, ice, agitation, or fluid dynamic forces, to operational service temperatures greater than 180°F (82°C) and to tanks with unsupported bottoms.1.5 The following safety hazards caveat pertains only to the test method portion, Section 11, of this specification: 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.NOTE 1: There is no known ISO equivalent to this standard.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： 646元 / 折扣价： 550 元 加购物车

5.1 The procedures in these test methods should be used with caution for acceptance of commercial shipments owing to the absence of factual information on the between-laboratory precision of many of the test procedures included in these test methods. It is recommended that any program of acceptance testing be preceded by an interlaboratory check in the laboratory of the purchaser and the laboratory of the supplier on replicate specimens of the materials to be tested for each property (or properties) to be evaluated.5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, test samples should be used that are as homogeneous as possible, that are drawn from the material from which the disparate test results were obtained, and that are randomly assigned in equal numbers to each laboratory for testing. Other materials with established test values may be used for this purpose. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results must be adjusted in consideration of the known bias.5.2 The significance and use of particular properties are discussed in the appropriate sections of specific test methods.1.1 These test methods cover the testing of industrial filament yarns made wholly of manufactured organic-base fibers, cords twisted from such yarns, fabrics woven from such cords, and products that are made specifically for use in the manufacture of pneumatic tires. They may be applied to similar yarns and cords used for reinforcing other rubber goods and for other industrial applications. The test methods apply to nylon, polyester, and rayon yarns and tire cords twisted from such yarns and to fabrics made from such cords. The yarn or cord may be wound on cones, tubes, bobbins, spools, or beams; may be woven into fabric; or may be in some other form. The methods include testing procedure only and include no specifications or tolerances.1.2 No procedure is included for the determination of fatigue resistance of cord, but several commonly used procedures for the measurement of fatigue resistance of cords in rubber were published in the appendix of these test methods in the 1967 Annual Book of ASTM Standards, Part 24, and in earlier issues of Test Methods D885.1.3 The sections on “Growth of Conditioned Yarns and Cords,” “Properties of Yarns and Cords at Elevated Temperature,” and “Properties of Wet Yarns and Cords” have been moved to Appendix X1 – Appendix X3 as non-mandatory informational items because of their very limited use by the industry and because precision and bias statements are not included.1.4 This standard includes the following sections:  SectionAdhesion of Cord to Elastomers 34Bibliography of Tire Cord Test Methods X5Breaking Strength (Force) of Yarns and Cords at Elevated Tempera- ture X2.3Breaking Strength (Force) of Conditioned Yarns and Cords 16Breaking Strength (Force) of Oven-Dried Rayon Yarns and Cords 23Breaking Strength (Force) of Rayon Yarns and Cords at Specified Moisture Regain Level, Adjustment of 17Breaking Tenacity of Conditioned Yarns and Cords 18Breaking Tenacity of Oven-Dried Rayon Yarns and Cords 24Breaking Toughness of Yarns and Cords 28Commercial Mass 9Conditioning 7Contraction of Wet Yarns and Cords X3Count of Tire Cord Fabric 37Dip (Adhesive) Solids Pickup on Yarns and Cords 33Elongation at Break of Conditioned Yarns and Cords 19Elongation at Break of Oven-Dried Rayon Yarns and Cords 25Elongation of Rayon Yarns and Cords at a Specified Moisture Regain Level, Adjustment of Observed 20Extractable Matter in Yarns and Cords 32Force at Specified Elongation (FASE) of Conditioned Yarns and Cords 21Force at Specified Elongation (FASE) of Oven-Dried Rayon Yarns and Cords 26Growth of Conditioned Yarns and Cords X1Identification of Fibers 8Keywords 40Linear Density 11Mass of per Unit Area of Tire Cord Fabric 36Modulus of Conditioned Yarns and Cords 22Moisture Regain, Actual 10Precision and Bias of Certain Yarn and Cord Tests 39  35 toProperties of Tire Cord Fabric 38Sampling 6Shrinkage Force of Conditioned Yarns and Cords at Elevated Temper- ature  X2.5Shrinkage of Conditioned Yarns and Cords at Elevated Temperature X2.4, General 5, Tensile Properties 14SI Calculations (examples for work-to-break, specific work-to-break, and breaking toughness)  X4Stiffness of Fabric 38  12 toTensile Properties of Yarns and Cords 28Terminology 3Thickness of Cords 31Twist in Yarns and Cords 30Width of Tire Cord Fabric 35Work-to-Break of Yarns and Cords 271.5 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.1.6 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 and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元

5.1 The procedures for the determination of properties of single-filament hose reinforcing wire made from steel are considered satisfactory for acceptance testing of commercial shipments of this product because the procedures are the best available and have been used extensively in the trade.5.1.1 In the case of a dispute arising from differences in reported test results when using these test methods for acceptance testing of commercial shipments, the purchaser and supplier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for investigation of bias. As a minimum, two parties should take a group of test specimens which are as homogeneous as possible and which are from a lot of material of the type in question. The test specimens then should be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared by using an appropriate statistical test and an acceptable probability level chosen by the two parties before testing is begun. If a bias is found, either its cause must be determined and corrected or the purchaser and supplier must agree to interpret future test results with consideration to the known bias.1.1 These test methods cover testing of single filament steel wires that are used to reinforce hose products. By agreement, these test methods may be applied to similar filaments used for reinforcing other rubber products.1.2 These test methods describe test procedures only and do not establish specifications or tolerances.1.3 These test methods cover the determinations of the mechanical properties listed below:  Property Section  Breaking force (strength)  7 – 13  Yield strength  7 – 13  Elongation  7 – 13  Knot strength 14 – 20  Torsion resistance 21 – 27  Reverse bend 28 – 34  Wrap 35 – 41  Diameter 42 – 481.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system 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.1.5 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.

定价： 0元 / 折扣价： 0 元

定价： 156元 / 折扣价： 133 元 加购物车

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 The goal of the NDT is to detect defects that have been implicated in the failure of the COPV metal liner, or have led to leakage, loss of contents, injury, death, or mission, or a combination thereof. Liner defects detected by NDT that require special attention by the cognizant engineering organization include through cracks, part-through cracks, liner buckling, pitting, thinning, and corrosion under the influence of cyclic loading, sustained loading, temperature cycling, mechanical impact and other intended or unintended service conditions.NOTE 3: Liners made from stainless steel and nickel-based alloys exhibit a higher damage resistance to impact than those made from aluminum.NOTE 4: Safe life is the goal for any COPV so that a through crack in the liner will not develop during the service life.NOTE 5: The use a material with good fatigue and slow crack growth characteristics is important. For example, nickel-based alloys are better than precipitation-hardened stainless steel. Aluminum also has good ductility and crack resistance.4.2 The COPVs covered in this guide consist of a metallic liner overwrapped with high-strength fibers embedded in polymeric matrix resin (typically a thermoset). 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 fiber). Matrix resins include epoxies, cyanate esters, polyurethanes, phenolic resins, polyimides (including bismaleimides), polyamides and other high performance polymers. Common bond line adhesives are generally epoxies (FM-73, West 105, and Epon 862) or urethanes with thicknesses ranging from 0.13 mm (0.005 in.) to 0.38 mm (0.015 in.). Metal liner and composite overwrap materials requirements are found in ANSI/AIAA S-080 and ANSI/AIAA S-081, respectively. Pictures of representative COPVs are shown in Guide E2981.4.3 The operative failure modes COPV metal liners and metal PVs, in approximate order of likelihood, are: (a) fatigue cracking, (b) buckling, (c) corrosion, (d) environmental cracking, and (e) overload.NOTE 6: For launch vehicles and satellites, the strong drive to reduce weight has pushed designers to adopt COPVs with thinner metal liners. Unfortunately, this configuration is more susceptible to liner buckling. Therefore, as a precursor to liner fatigue, attention should be paid to liner buckling.4.4 Per MIL-HDBK-340, 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 Per NASA-STD-(I)-5019, COPVs should 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) should 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 7: 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 standard is intended to reduce the likelihood of liner failure, commonly denoted leak before burst (LBB), characterized by leakage and loss of the pressurized commodity, thus mitigating or eliminating the attendant risks associated with loss of the pressurized commodity, and possibly 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 Per 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-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. COPV composite overwraps can have a myriad of possible discontinuity types, with varying degrees of importance in terms of effect on performance (see 4.7 in Guide E2981). As for discontinuities in the metallic liner, the primary concern from an NDT perspective is to detect discontinuities that can develop cracks or reduce residual strength of the liner below the levels required, within the context of the life cycle. Therefore, discontinuities should be categorized as follows:4.7.1 Inherent material discontinuities: inclusions, grain boundaries, etc., detected during (a) and (b) of 5.5.NOTE 8: Inherent material discontinuities are generally much smaller than the damage-tolerance limit size. Any design that does not satisfy this statement should be revised. Quality control procedures in place in the manufacturing process should eliminate any source materials that do not satisfy specifications.4.7.2 Manufacturing-induced discontinuities: caused by welding, machining, heat treatment, etc., detected during (b) and (c) of 5.5.NOTE 9: Manufacturing-induced discontinuities depend on the manufacturing process, and can include machining marks, improper heat treatment, and weld-related discontinuities such as lack of fusion, porosity, inclusions, zones of local material embrittlement, shrinkage, and cracking.4.7.3 Service-induced discontinuities: fatigue, corrosion, stress corrosion cracking, wear, accidental damage, etc. detected during (d) and (e) of 5.5 (after the COPV has been installed). In these cases, NDT should either be made on a “remove and inspect” or “in-situ” basis depending on the procedure and equipment used.4.8 A conservative damage-tolerance life assessment is made by assuming the existence of a crack-like discontinuity or system of discontinuities, and determining the maximum size or other characteristic of this discontinuity(s) that can exist at the time the vessel is placed into service but not progress to failure under the expected service conditions. This then defines the dimensions or other characteristics of the crack or crack-like discontinuity or system of crack-like discontinuities that should be detected by NDT.NOTE 10: Welding or machining may result in non-crack like flaws/imperfections/conditions that may be important, and NDT choices for these flaws/imperfections/conditions may be different than for crack-like ones.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 result 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 PVs—ANSI/AIAA S-080 defines the approach for design, analysis, and certification of metallic PVs.4.11 Certification of COPVs—ANSI/AIAA S-081 defines the approach for design, analysis, and certification of COPVs, while ANSI/AIAA S-080 defines the approach for design, analysis, and certification of PVs. More specifically, the PV or COPV thin-walled metal liner should exhibit a leak before burst (LBB) failure mode or shall 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 procedure 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 assessment of crack growth is the typical approach used for 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.4.11.1 Design Requirements—COPV design requirements related to the metallic liner are given in ANSI/AIAA S-080. The key requirement is the stipulation that the PV or COPV thin-walled metal liner should exhibit an LBB failure mode or should possess adequate damage tolerance life (safe-life), or both. The overwrap design should 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.4.12 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 procedure 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. 1) depends on the number of examination sites with targets, the size of the targets at the examination sites, and the basic nature of the examination result (hit/miss or magnitude of signal response).FIG. 1 Probability of Detection as a Function of Flaw Size, 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)4.12.1 Given that a90/95 has become a de facto design criterion, it is 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 11: a90/95 for a metallic liner and generation of a POD(a) function is predicated on the assumption that critical initial flaw size (CIFS) for a liner of a given thickness can be detected with a capability of 90/95 (90 percent probability of detection at a 95 percent confidence level). This is problematic for COPVs with very thin metallic liners where the CIFS will be smaller than the minimum detectable flaw sizes given in Table 1 in NASA-STD-5009. At this limit of detection (CIFS < a90/95), a90/95 will have no validity for a thin-walled COPV.4.12.2 NASA-STD-5009 defines typical limits of NDT capability for a wide range of NDT procedures and applications. Given the defect criteria established by the Damage-Tolerance Life requirements and the potential discontinuities to be detected, NASA-STD-5009 can be used to select NDT procedures that are likely to achieve the required examination capability.NOTE 12: NDT of fracture critical hardware should detect the initial crack sizes used in the damage tolerance fracture analyses with a capability of 90/95. The minimum detectable crack sizes for the standard NDT procedures shown in Table 1 of NASA-STD-5009 meet the 90/95 capability requirement. The crack size data in Table 1 of NASA-STD-5009 are based principally on an NDT capability study that was conducted on flat, fatigue-cracked 2219-T87 aluminum panels early in the Space Shuttle program. Although many other similar capability studies and tests have been conducted since, none have universal application, neither individually or in combination. Conducting an ideal NDT capability demonstration where all of the variables are tested is obviously unmanageable and impractical.4.12.3 Aspect Ratio and Equivalent Area Considerations—Current standards governing aerospace metallic pressure vessels (ANSI/AIAA S-080) and COPV liners (ANSI/AIAA S-081) require that fracture analysis be performed to determine the CIFS for cracks having an aspect ratio ranging from 0.1 to 0.5. However, there is insufficient data to support the approach of testing at only one aspect ratio and then using an equivalent area approach to extend the results to the required range of aspect ratios (1-9).20 Accordingly, POD testing on metallic COPV liners should be performed at the bounds of the required range of crack aspect ratios.NOTE 13: Caution: To minimize mass, designers of aerospace systems are reducing the wall thickness for metallic pressure vessels and COPV liners. This reduction in wall thickness produces higher net section stresses, for a given internal pressure, resulting in smaller CIFS. These smaller crack sizes approach the limitations of current NDT. Failure to adequately demonstrate the capabilities of a given NDT procedure over the required range of crack aspect ratios may lead to the failure to detect a critical flaw resulting in a catastrophic tank failure.4.12.4 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.4.12.5 For purposes of POD studies, the NDT procedure should be classified into one of three categories:4.12.5.1 Those which produce only qualitative information as to the presence or absence of a flaw, that is, hit/miss data,4.12.5.2 Those which also provide some quantitative measure of the size of the target (for example, flaw or crack), that is, â versus a data, and4.12.5.3 Those which produce visual images of the target and its surroundings.4.12.6 Detailed POD Guidance—For detailed guidance on how to conduct a POD study, including system definition and control, calibration, noise, demonstration design, demonstration tests, data analysis, presentation of results, retesting, and process control plan, consult MIL-HDBK-1823.4.12.6.1 For detailed guidance on how to conduct a POD study for ET, PT, and UT, consult MIL-HDBK-1823, Appendices A through D, respectively.4.12.6.2 For detailed test program guidance; specimen design, fabrication, documentation, and maintenance; statistical analysis of NDT data; model-assisted determination of POD; special topics; and related documents, consult MIL-HDBK-1823, Appendices E through J, respectively.4.13 NDT Data Reliability—MIL-HDBK-1823 provides nonbinding guidance for estimating the detection capability of NDT procedures for examining either new or in-service hardware for which a measure of NDT reliability is needed. Specific guidance is given in MIL-HDBK-1823 for ET, PT, and UT. MIL-HDBK-1823 may be used for other NDT procedures, such as RT or Profilometry, provided they provide either a quantitative signal, â, or a binary response, hit/miss. Because the purpose is to relate POD with target size (or any other meaningful feature like chemical composition), “size” (or feature characteristic) should be explicitly defined and be unambiguously measurable, that is, other targets having similar sizes will produce similar output from the NDT equipment. This is especially important for amorphous targets like corrosion damage or buried inclusions with a significant chemical reaction zone. Other literature on NDT data reliability is given elsewhere (2-7).NOTE 14: AE as generally practiced does not yield the size of a flaw in a metallic liner of a COPV; however, can be used for accept-reject of COPVs (see Section 7 in both this guide and Guide E2981).4.14 Further Guidance—Additional guidance for fracture control is provided in other governmental documents (NASA-STD-5003, SSP 30558, SSP 52005, NSTS 1700.7B), and non-government documents (NTIAC-DB-97-02, NTIAC-TA-00-01).1.1 This guide discusses current and potential nondestructive testing (NDT) procedures for finding indications of discontinuities in thin-walled metallic liners in 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 percent 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 COPV. However, it also has relevance to (1) monolithic metallic pressure vessels (PVs) (CGA Type I), and (2) metal-lined hoop-wrapped COPVs (CGA Type II).1.3 The vessels covered by this guide are used in aerospace applications; therefore, examination 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 and PVs used for storing aerospace media at maximum allowable working pressures (MAWPs) up to 3.5 MPa (500 psia) and volumes up to 2000 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.1.5 The metallic liners under consideration include, but are not limited to, ones made from aluminum alloys, titanium alloys, nickel-based alloys, and stainless steels. In the case of COPVs, the composites through which the NDT interrogation should be made after overwrapping include, but are not limited to, various polymer matrix resins (for example, epoxies, cyanate esters, polyurethanes, phenolic resins, polyimides (including bismaleimides), polyamides) with continuous fiber reinforcement (for example, carbon, aramid, glass, or poly-(phenylenebenzobisoxazole) (PBO)).1.6 This guide describes the application of established NDT procedures; namely, Acoustic Emission (AE, Section 7), Eddy Current Testing (ET, Section 8), Laser Profilometry (LP, Section 9), Leak Testing (LT, Section 10), Penetrant Testing (PT, Section 11), and Radiographic Testing (RT, Section 12). These procedures can be used by cognizant engineering organizations for detecting and evaluating flaws, defects, and accumulated damage in metallic PVs, the bare metallic liner of COPVs before overwrapping, and the metallic liner of new and in-service COPVs.1.7 All methods discussed in this guide (AE, ET, LP, LT, PT, and RT) are performed on the metallic liner of COPVs before or after overwrapping and structural cure. The same methods may also be performed on metal PVs. For NDT procedures for detecting discontinuities in the composite overwrap in filament wound pressure vessels; namely, AE, ET, Shearography Testing (ST), RT, Ultrasonic Testing (UT) and Visual Testing (VT); consult Guide E2981.1.8 Due to difficulties associated with inspecting thin-walled metallic COPV liners through composite overwraps, and the availability of the NDE methods listed in 1.6 to inspect COPV liners before overwrapping and metal PVs, ultrasonic testing (UT) is not addressed in this standard. UT may still be performed as agreed upon between the supplier and customer. Ultrasonic requirements may utilize Practice E2375 as applicable based upon the specific liner application and metal thickness. Alternate ultrasonic inspection methods such as Lamb wave, surface wave, shear wave, reflector plate, etc. may be established and documented per agreed upon contractual requirements. The test requirements should be developed in conjunction with the specific criteria defined by engineering analysis.1.9 In general, AE and PT are performed on the PV or the bare metallic liner of a COPV before overwrapping (in the case of COPVs, AE is done before overwrapping to minimize interference from the composite overwrap). ET, LT, and RT are performed on the PV, bare metallic liner of a COPV before overwrapping, or on the as-manufactured COPV. LP is performed on the inner and outer surfaces of the PV, or on the inner surface of the COPV liner both before and after overwrapping. Furthermore, AE and RT are well suited for evaluating the weld integrity of welded PVs and COPV liners.1.10 Wherever possible, the NDT procedures described should be sensitive enough to detect critical flaw sizes of the order of 1.3 mm (0.050 in.) length with a 2:1 aspect ratio.NOTE 2: Liners often fail due to improper welding resulting in initiation and growth of multiple small discontinuities of the order of 0.050 mm (0.002 in.) length. These will form a macro-flaw of 1-mm (0.040-in.) length only at higher stress levels.1.11 For NDT procedures that detect discontinuities in the composite overwrap of filament-wound pressure vessels (namely, AE, ET, shearography, thermography, UT and visual examination), consult Guide E2981.1.12 In the case of COPVs which are impact damage sensitive and require implementation of a damage control plan, emphasis is placed on NDT procedures that are sensitive to detecting damage in the metallic liner caused by impacts at energy levels which may or may not leave any visible indication on the COPV composite surface.1.13 This guide does not specify accept/reject criteria (4.10) used in procurement or used as a means for approving PVs or COPVs for service. Any acceptance criteria provided herein are given mainly for purposes of refinement and further elaboration of the procedures described in the 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.1.14 This guide references established ASTM test methods that have a foundation of experience and that yield a numerical result, and newer procedures that have yet to be validated which 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.1.15 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 thin-walled metallic component design, quality assurance, in-service maintenance, or damage examination.1.16 Units—The values stated in metric units are to be regarded as the standard. The English units given in parentheses are provided for information only.1.17 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.1.18 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 machine-made reinforced thermosetting resin pressure pipe (RTRP) manufactured by the filament winding process. This specification does not include reinforced polymer mortar pipe (RPMP), which is another type of fiberglass pipe. The pipes are generally classified by type, grade, class, and hydrostatic design. In addition, a secondary cell classification system defines the basic mechanical properties of the pipe. The resins, reinforcements, colorants, fillers, and other materials, when combined as a composite structure, shall produce a pipe that shall meet the performance requirements of this specification. Materials shall be tested and the individual grades shall conform to the specified values of dimensions and tolerances, long-term static hydrostatic strength, long-term cyclic hydrostatic strength, short-term hydrostatic failure strength, longitudinal tensile properties, and stiffness factor.1.1 This specification covers machine-made reinforced thermosetting resin pressure pipe (RTRP) manufactured by the filament winding process up to 60 in. nominal size. Included are a classification system and requirements for materials, mechanical properties, dimensions, performance, methods of test, and marking.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are provided for information purposes only.1.3 The following safety hazards caveat pertains only to the test method portion, Section 8, of this specification: 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.NOTE 1: The term “fiberglass pipe” as described in Section 3 of this specification applies to both reinforced thermosetting resin pipe (RTRP) and reinforced polymer mortar pipe (RPMP). This specification covers only reinforced thermosetting resin pipe (RTRP).NOTE 2: There is no known ISO equivalent to this standard.NOTE 3: This specification is applicable to RTRP where the ratio of outside diameter to wall thickness is 10:1 or more.NOTE 4: For the purposes of this standard, polymer does not include natural polymers.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.

定价： 590元 / 折扣价： 502 元 加购物车

10.1 The pressure-sensitive, filament-reinforced tapes covered by this specification are intended for use in closing and reinforcing fiberboard boxes and for bundling items for shipment.10.2 Type I is an impact and cut-resistant low-tensile strength tape, usually with polyester fiber reinforcement. It is intended for bundling and similar applications and used where a greater amount of stretch before break provides an improvement in impact resistance over glass filament reinforcement.10.3 Types II and III are intended for reinforcement of RSC's and similar fiberboard boxes, and for bundling where a snug bundle must be maintained and other similar applications.10.4 Type IV is intended for applications in which weather-resistance high-tensile strength tape is required.10.5 See Practice D1974/D1974M for details on applications.AbstractThis specification covers filament-reinforced, pressure-sensitive adhesive tape for packaging and includes the following types: Type I, Type II, Type III, and Type IV. The tapes covered by this specification are intended for use in closing and reinforcing fiberboard boxes and for bundling items for shipment. The materials used in the construction of the tapes shall be such that they ensure performance of the tape over the prescribed temperature range. The material and manufacture requirements for backing, adhesive, reinforcements, and rolls are specified. The tape shall comply with the physical property requirements such as (1) adhesion before and after aging, (1) adhesion at low temperature, (3) elongation, (4) shear adhesion, (5) break strength, and (6) thickness. Additional physical requirements are specified for Type IV tape. The tape shall meet the prescribed dimension (including the roll width, roll length, and splice overlap), color, and transparency requirements. The sampling method for end-item examination and end-item testing are given. Accelerated aging (heat and humidity), adhesion, break strength and elongation, thickness, and weathering (for Type IV only) tests shall be performed. Environmental considerations such as toxic content are also specified.1.1 This specification covers filament-reinforced, pressure-sensitive adhesive tape.1.2 The values stated in either inch-pound or SI units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore each system must be used independently of the other, without combining values in any way.1.3 The following precautionary caveat pertains only to the test methods portion, Section 14, of this specification: 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.

定价： 515元 / 折扣价： 438 元 加购物车

1.1 This test method covers the preparation, mounting, and testing of high-modulus single-filament materials [over > 21 10 9 Pa (> 3 106 psi)] for the determination of tensile strength and Young's modulus, at room temperature.1.2 This test method is limited to single filaments utilizing a fixed gage length at least 2000 times longer than the nominal filament diameter.1.3 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns 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.

定价： 0元 / 折扣价： 0 元

5.1 The properties determined by these test methods are of value in material specifications, qualifications, data base generation, certification, research, and development.5.2 These test methods are intended for the testing of fibers that have been specifically developed for use as reinforcing agents in advanced composite structures. The test results of an impregnated and consolidated fiber should be representative of the strength and modulus that are available in the material when used as intended. The performance of fibers in different resin systems can vary significantly so that correlations between results using these test methods and composite testing may not always be obtained.5.3 The reproducibility of test results is dependent upon precise control over all test conditions. Resin type, content and distribution, curing process, filament alignment, gripping in the testing machine, and alignment in the testing machine are of special importance.5.4 The measured strengths of fibers are not unique quantities and test results are strongly dependent on the test methods used. Therefore the test method described here will not necessarily give the same mean strengths or standard deviations as those obtained from single filaments, dry fibers, composite laminas, or composite laminates.1.1 These test methods cover the preparation and tensile testing of resin-impregnated and consolidated test specimens made from continuous filament carbon and graphite yarns, rovings, and tows to determine their tensile properties.1.2 These test methods also cover the determination of the density and mass per unit length of the yarn, roving, or tow to provide supplementary data for tensile property calculation.1.3 These test methods include a procedure for sizing removal to provide the preferred desized fiber samples for density measurement. This procedure may also be used to determine the weight percent sizing.1.4 These test methods include a procedure for determining the weight percent moisture adsorption of carbon or graphite fiber.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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.

定价： 590元 / 折扣价： 502 元 加购物车