Annex 4A: paragraph 4

Transcription

1 Submitted by the expert from ISO (TC 58/SC 3) Informal document GRSG Rev.1 (111th GRSG, October 2016, Agenda item 9.) - Update the standards with a line like: all reference to standards like ISO are always to the latest version unless stated otherwise. - Update Annex II with: Series of PRD/TPRD s are not allowed - Update A.24 with the pressure relief device shall comply with the requirements given in annex 4A for the specific type - Update Annex 4A para 4 and para 7 with reference to ISO A.24. Pressure relief device requirements Pressure relief devices shall meet the requirements to Annex 4A paragraph 7 of this regulation Annex 4A: paragraph 4 4. THE PRESSURE RELIEF VALVE AND PRESSURE RELIEF DEVICE General: Pressure relief devices shall meet the requirements of ISO The materials constituting the pressure relief valve and pressure relief device which are in contact with the CNG when operating, shall be compatible with the test CNG. In order to verify this compatibility, the procedure described in Annex 5D shall be used. 7. PRESSURE RELIEF DEVICE (PRESSURE TRIGGERED) 7.1. The materials constituting the PRD (pressure triggered) which are in contact with the CNG when operating, shall be compatible with the test CNG. In order to verify this compatibility, the procedure described in Annex 5D shall be used. From ISO : The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. 3.4 parallel combination relief device pressure relief device (PRD) activated by high temperature or pressure acting separately NOTE This device may be integrated into one device that has independent pressure activated and thermally activated parts. It may also be formed by two independent devices (one pressure activated and one thermally activated) that act independently. Each part of the device shall not interfere with the operation/activation of the other part. The device shall be able to vent the content of the cylinder through any one of the parts of the PRD independently. The device shall be able to vent the content of the cylinder if the pressure and thermally activated parts open simultaneously Test thermally activated relief devices in accordance with Series combination relief devices, activated by a combination of high pressures and temperatures acting together, shall be tested in accordance with Parallel combination relief devices, activated by high pressure and temperatures acting separately, shall be tested in accordance with Parallel combination relief devices Test procedure

2 a) Test the thermally activated part of the PRD following the tests of b) Activate the pressure activated part of the PRD by pressurizing until the rupture disc bursts Requirements The PRDs subjected to the tests of 6.5, 6.8, 6.9 and the corrosion resistance and vibration tests of ISO , shall be subjected to the test procedure in and meet the following requirements: a) the thermal part of the PRDs shall meet the requirements of ; b) the pressure activated part shall activate at a pressure > 75 % and < 105 % of the activation pressure of a PRD not subjected to any previous testing. The PRD assembly shall be cycled 1,000 times between not more than 10 % of the manufacturer s specified service pressure and not less than 100 % of the manufacturer s specified working pressure. This test shall be conducted at ambient temperature. The maximum pressure cycling rate is 10 cycles per minute. Following this test, the PRD shall be activated by pressurizing until the device relieves pressure. The PRDs subjected to pressure cycling, thermal cycling, salt corrosion resistance, gas condensate corrosion resistance and impact due to drop and vibration, shall activate at a pressure which is at least 130 % of the manufacturer s specified service pressure, and is at least 75 % of the activation pressure, but is not more than 105 % of the activation pressure, of the PRD which had not been subjected to previous design qualification tests. Proposal of Amendment to Regulation Insert new paragraph 23.3: "23.3 Type approvals granted according to 00 series of amendments of this regulation to components other than fuel rail, as defined in 2.28, remain valid and may be used for the purpose of par " Justification: The 01 series of amendments of Regulation 110 introduces the new component fuel rail as well as its definition, requirements and tests. The new Regulation doesn t introduce further requirements for existing components but, without clarification, seems the R required a new type approval procedure for the cited existing components. Since the provisions of all other existing components remain unchanged, it should be clarified that they can be fitted in vehicles respecting the installation requirements of Regulation series of amendments. "23. Transitional Provisions As from the official date of entry into force of the 031 series of amendments to this Regulation, no Contracting Party 2

3 applying this Regulation shall refuse to grant or refuse to accept type approval under this Regulation as amended by the 031 series of amendments As from 12 months after the date of entry into force of the 031 series of amendments to this Regulation, Contracting Parties applying this Regulation shall grant approvals only if the type of components to be approved meets the requirements of Part I of this Regulation as amended by the 031 series of amendments to this Regulation As from 18 months after the date of entry into force of the 031 series of amendments to this Regulation, Contracting Parties applying this Regulation shall grant approvals only if the vehicle type to be approved meets the requirements of Part II of this Regulation as amended by the 031 series of amendments to this Regulation Until 12 months after the date of entry into force of the 031 series of amendments to this Regulation, Contracting Parties applying this Regulation can continue to grant type approvals for the type of components to the original version of this Regulation without taking into account the provisions of the 031 series of amendments Until 18 months after the date of entry into force of the 031 series of amendments to this Regulation, Contracting Parties applying this Regulation can continue to grant type approvals for the vehicle type to the original version of this Regulation without taking into account the provisions of the 031 series of amendments Notwithstanding the provisions of paragraphs and 23.5., Contracting Parties applying this Regulation shall not refuse to grant extensions of type approvals for existing types of component or vehicle types which have been issued according to this Regulation without taking into account the provisions of the 031 series of amendments to this Regulation." Rationale for the proposed amendments to Regulation No. 110 (CNG/LNG vehicles) The text reproduced below was prepared by the expert from the International Organization for Standardization (ISO). The expert is the Convener of the Working Group (ISO TC 58/SC 3/WG 17) responsible for the ISO standard High pressure cylinders for the on- board storage of natural gas as a fuel for automotive vehicles. The proposed changes are for the purpose of harmonizing the CNG cylinder requirements in Regulation No. 110 with the requirements in the ISO 11439: 2013 standard. The proposed changes in ECE/TRANS/WP.29/GRSG/2016/22 are a follow-up to the discussion that occurred during the 110th session of the Working Party on General Safety Provisions (see report 3

4 ECE/TRANS/WP.29/GRSG/89, paras ). The modifications to the current text of UN Regulation No. 110 are marked by strikethroughs and in bold characters. Justification The justification (marked in red characters) for this proposal was previously presented in the document ECE R110 Annex 3 & ISO High pressure cylinders for the onboard storage of natural gas as a fuel for automotive vehicles, Informal document GRSG (106th GRSG, 5 9 May 2014, agenda item 8). Proposal - Alignment with ISO 11439: Proposed Revisions to: E/ECE/324/Rev.2/Add.109/Rev.3 E/ECE/TRANS/505/Rev.2/Add.109/Rev.3 Regulation No. 110 Uniform provisions concerning the approval of: I. Specific components of motor vehicles using compressed natural gas (CNG) and/or liquefied natural gas (LNG) in their propulsion system II. Vehicles with regard to the installation of specific components of an approved type for the use of compressed natural gas (CNG) and/or liquefied natural gas (LNG) in their propulsion system Prepared By: Craig Webster, P.Eng. Convener ISO TC 58/SC 3/WG 17 for the ISO Standard craig.webster@csagroup.org 4

5 2. References ASTM Standards ASTM B Test method of Salt Spray (Fog) Testing Replaced by reference to ISO 9227 equivalent. ASTM B Mercurous Nitrate Test for Copper and Copper Alloys No longer use mercurous nitrate as very dangerous chemical to handle replaced by less dangerous test specified under for PRD testing per tests defined in ASTM D a Mandrel Bend Test of aattached Organic Coatings Corrected reference. ASTM D Test Method for Apparent interlaminar Shear Strength of Parallel Fibre Composites by Short Beam Method Replaced by reference to ISO equivalent. ASTM D Test Method for Resistance of Organic Coatings to the Effects of Rapid Deformation (Impact) Corrected date of reference. ASTM D3359 Standard Test Methods for Measuring Adhesion by Tape Test Replacement for ISO 4624 (incorrect reference) ASTM D4814 Standard Specification for Automotive Spark-Ignition Engine Fuel Standard added for Environmental test chemical. ASTM D Test Method for Transition Temperatures Polymers by Thermal Analysis Editorial. ASTM E Standard Test, Method for Measurement of Fatigue Crack Growth Rates No longer required, as no longer calculate fatigue crack growth rates in the Regulation (see also F.3.1) ASTM E Test Method for JIC, a Measure of Fracture Toughness No longer required, as fracture mechanics calculation methods deleted ASTM G53-93 Standard Practice for Operating Light and Water Exposure Apparatus (Fluorescent UVCondensation Type) for Exposure of nonmetallic Materials Superseded by ASTM G154 (see also A.9.1). ASTM G154-12a Standard Practice for Operating Fluorescent Light Apparatus for UV Exposure of Nonmetallic Materials ASTM replacement for ASTM G53 (see also A.9.1). BSI Standards3 BS 5045 Part 1 (1982) Transportable Gas Containers Specification for Seamless Steel Gas Containers Above 0.5 litre Water Capacity Replaced by equivalent ultrasonic requirements as specified in ISO standard. 5

6 BS Fracture Mechanics Toughness Tests Part I Method for Determination of KIC, Critical COD and Critical J Values of BS PD Guidance an Methods for Assessing the A Acceptability of Flaws in Fusion Welded Structures; Metallic Materials Deleted since the use of fracture mechanics calculations for leak-before-break are no longer part of a performance standard. EN Standards EN Transportable gas cylinders Refillable welded steel gas cylinders Design and construction Part 2: Stainless steel Stainless steels are no longer part of the regulation. EN ISO Arc-welded joints in steel; guidance on quality levels for imperfections Welding is no longer part of the regulation. EN 895:1995 Destructive tests on welds in metallic materials. Transverse tensile test Welding is no longer part of the regulation. EN 910:1996 Destructive test methods on welds in metallic materials. Bend tests Welding is no longer part of the regulation. EN 1435:1997 Non-destructive examination of welds. Radiographic examination of welded joints Welding is no longer part of the regulation. EN :2009 Metallic materials. Tensile test Replaced by reference to equivalent ISO 6892 standard. EN :1990 Charpy impact test on metallic materials. Test method (V- and U-notches) Replaced by reference to equivalent ISO standard. ISO Standards ISO Steel Charpy Impact Test (v-notch) Replaced by ISO (updated version) ISO 148-1, Metallic materials Charpy pendulum impact test Part 1: Test method Updated reference. ISO 527 Pt 1-93 Plastics - Determination of Tensile Properties Part I: General principles-2, Plastics Determination of tensile properties Part 2: Test conditions for moulding and extrusion plastics Updated reference. ISO Steel-Hardenability Test by End Quenching (Jominy Test) The hardenability test is no longer a requirement for steels in the ISO 9809 series of standards. Suitability of the steel for CNG service is determined by performance tests. ISO 9227 Corrosion tests in artificial Atmospheres Salt spray tests ISO equivalent replacement for ASTM B117. ISO Fibre-reinforced plastic composites Determination of apparent interlaminar shear strength by short-beam method 6

7 ISO equivalent replacement for ASTM D2344. ISO Paints and Varnishes Determination of film Tthickness Editorial. ISO Glass Reinforced Materials Determination of Tensile Properties ISO 3628 is for photography processing chemicals. The correct reference is ISO Plastics -- Determination of tensile properties -- Part 2: Test conditions for moulding and extrusion plastics. ISO Plastics and Varnishes Pull-off Test for adhesion Replaced by use of ASTM D3359 as ISO 4624 was found not to be equivalent to the ASTM standard. ISO Metallic Materials Tensile Testing Wrong designation was previously used. ISO Metallic Materials Hardness test Brinell Test Editorial. ISO Metallic Materials Hardness Tests Rockwell Test (Scales, ABCDEFGHK) This standard is not referenced in text of the Regulation. ISO/DIS Refillable Transportable Sseamless Aaluminium Aalloy gas Ccylinders for Worldwide Usage Design, construction and testing Manufacture and Acceptance Updated reference. ISO/DIS 9809 Transportable Seamless Steel Gas Cylinders Design, Construction and Testing Part I: Quenched and Tempered Steel Cylinders with Tensile Strength < 1,100 MPa ISO , Gas cylinders Refillable seamless steel gas cylinders Design, construction and testing Part 1: Quenched and tempered steel cylinders with tensile strength less than MPa Updated reference as ISO 9809 is no longer a DIS. ISO , Gas cylinders Refillable seamless steel gas cylinders Design, construction and testing Part 2: Quenched and tempered steel cylinders with tensile strength greater than or equal to MPa ISO , Gas cylinders Refillable seamless steel gas cylinders Design, construction and testing Part 3: Normalized steel cylinders Expanded the use of the ISO 9809 series of standards for steel cylinders. ISO/DIS Metallic Materials Determination of the Plane-Strain Fracture Toughness No longer use fracture mechanics calculation approach in the standard rely instead on performance tests. ISO Natural gas Natural gas for use as a compressed fuel for vehicles Part 1: Designation of the quality ISO/TR Natural gas Natural gas for use as a compressed fuel for vehicles Part 2: Specification of the quality Standards for natural gas quality were previously not available. These replace the use of SAE J1616. ISO , Road vehicles Compressed natural gas (CNG) fuel system components Part 13: Pressure relief device (PRD) 7

8 Comprehensive test program for PRDs compared to the single test previously used in A.24 of the Regulation. ISO Gas cylinders High pressure cylinders for the on-board storage of natural gas as a fuel for automotive vehicles No need to reference ISO as all requirements in the standard have been included in ECE R Definitions 4.4. "Working pressure" means the maximum pressure to which a component is designed to be subjected to and which is the basis for determining the strength of the component under consideration. For CNG cylinder, the settled pressure of 20 MPa at a uniform temperature of 15 C. For LNG tank, the pressure of the LNG tank primary relief valve setting. Specification of 20 MPa as the only working pressure for CNG has been removed, as there are parts of the world that use 25 MPa and 35 MPa for CNG "Maximum developed pressure" means the settled pressure developed when gas in a cylinder filled to the working pressure is raised to the maximum service temperature. This term is not used in the Regulation. Annex 3A Gas cylinders - High pressure cylinder for the on-board storage of CNG compressed natural gas as a fuel for automotive vehicles 1. Scope Service conditions to which the cylinders will be subjected are detailed in paragraph 4. of this annex. This annex is based upon a working pressure for natural gas as a fuel of 20 MPa settled at 15 C with a maximum filling pressure of 26 MPa. Other working pressures can be accommodated by adjusting the pressure by the appropriate factor (ratio). For example, a 25 MPa working pressure system will require pressures to be multiplied by Although this annex uses 20 MPa as a reference working pressure, other working pressures can[sj1] be used. There is no scientific reason to limit CNG working pressure to 20 MPa other working pressures (25 MPa and 35 MPa) for CNG have been used without problems elsewhere in the world. 4 Service conditions 4.2. Maximum pressures This annex is based upon a working pressure of 20 MPa settled at 15 C for natural gas as a fuel with a maximum filling pressure of 26 MPa. Other working pressures may be accommodated by adjusting the pressure by the appropriate factor (ratio); e.g. a 24 MPa working pressure system will require pressures to be multiplied by 1,20. Except where pressures have been adjusted in this way, Tthe cylinder pressure shall be limited to the following: The added statement clarifies the fact that other working pressures may be used, and how testing pressures must be adjusted accordingly. (a) (b) A pressure that would settle to 20 MPa at a settled temperature of 15 C; 26 MPa, immediately after filling, regardless of temperature; 8

9 4.3 Maximum number of filling cycles Cylinders are designed to be filled up to a settled pressure of 20 MPa (200 bar) at a settled gas temperature of 15 C for up to 1,000 times per year of service. This statement regarding fill pressures is already made in clause 4.2 above Gas composition General Cylinders shall be designed to tolerate being filled with natural gas meeting the specification of ISO and ISO/TR , and either of dry gas or wet gas as described in or 4.5.3, respectively. Methanol and/or glycol shall not be deliberately added to the natural gas. Cylinder should be designed to tolerate being filled with natural gas meeting either of the following three conditions: (a) SAE J1616 (b) Dry gas Water vapour would normally be limited to less than 32 mg/m3 at a pressure dew point of -9 C at 20 MPa. There would be no constituent limits for dry gas, except for: Hydrogen sulphide and other soluble sulphides: 23 mg/m3 Oxygen: 1 per cent by volume Hydrogen shall be limited to 2 per cent by volume when cylinders are manufactured from steel with an ultimate tensile strength exceeding 950 MPa; (c) Wet gas Gas that contains water content higher than b) normally meets the following constituent limits; Hydrogen sulphide and other soluble sulphides: 23 mg/m3 Oxygen: 1 per cent by volume Carbon dioxide: 4 3 per cent by volume Hydrogen: 0.1 per cent by volume Under wet gas conditions, a minimum of 1 mg of compressor oil per kg of y to protect metallic cylinders and liners. Replaced reference to the SAE J1616 natural gas specification with the ISO specifications for natural gas, and decreased the carbon dioxide limit to 3 per cent by volume to correspond with the value currently in ISO Design Type approval procedure 5.1. General The following information shall be submitted by the cylinder designer with a request for approval to the Type Approval Authority: The cylinder design is not approved, but the Type is approved - the wording in the Regulation itself says Type Approval Authority. 6. Requirements applicable to all cylinder types 9

10 6.1. General The following requirements are generally applicable to the cylinder types specified in paragraphs 7. to 10. of this annex. The design of cylinders shall cover all relevant aspects which are necessary to ensure that every cylinder produced according to the design is fit for its purpose for the specified service life; Type CNG-1 steel cylinders designed in accordance with ISO 9809 and meeting all the requirements therein are only required to meet the requirements of paragraphs and 6.9. to below. It was stated that ISO 9809 designs are acceptable for CNG service, provided they meet the materials and design test requirements in ISO Instead, it has been decided that the preferred approach is to give ISO 9809 designs exemptions from certain tests in ISO These exemptions are provided in clause 7.4 of the Regulation Steel Composition (b) Nickel, chromium, molybdenum, boron and vanadium contents, and any other alloying elements intentionally added. The following limits shall not be exceeded in the cast analysis: Tensile strength < 950 MPa 950 MPa Sulphur per cent per cent Phosphorus per cent per cent Sulphur and phosphorus per cent per cent When carbon-boron steel is used, a hardenability test in accordance with ISO 642, shall be performed on the first and last ingot or slab of each heat of steel. The hardness as measured in a distance of 7.9 mm from the quenched end, shall be within the range HRC, or HV, and shall be certified by the material manufacturer; The ISO 9809 series of standards no longer recognize the higher level of impurities previously allowed for lower strength steels. They only require the one set of limits for steels regardless of tensile strength. The hardenability test is no longer a requirement for steels in the ISO 9809 series of standards. Suitability of the steel for CNG service is determined by performance tests Bending properties The bending properties of the welded stainless steel in the finished liner shall be determined in accordance with paragraph A.3. (Appendix A to this annex). Welded steel is no longer accepted in the R.110 regulation Macroscopic weld examination A macroscopic weld examination for each type of welding procedure shall be performed. It shall show complete fusion and shall be free of any assembly faults or unacceptable defects as specified according to level C in EN ISO Welds are no longer accepted in the R.110 regulation Aluminium 10

11 Tensile properties The mechanical properties of the aluminium alloy in the finished cylinder shall be determined in accordance with paragraph A.l. (Appendix A to this annex). The elongation for aluminium cylinder material in Type CNG-1 cylinders and aluminum liner material in[sj2] Type CNG-2 cylinders shall be at least 12 per cent. The elongation for aluminum liner material in Type CNG-3 cylinders shall meet the manufacturer s design specifications. Type 3 designs do not require elongation limitations, as the carbon fibre overwrap prevents the aluminum elongation from exceeding the 2% elongation of the carbon fibre Plastic liners The tensile yield strength and ultimate elongation shall be determined in accordance with paragraph A.22. (Appendix A to this annex). Tests shall demonstrate the ductile properties of the plastic liner material at temperatures of -50 C or lower by meeting the values specified by the manufacturer; the polymeric material shall be compatible with the service conditions specified in paragraph 4. of this annex. In accordance with the method described in paragraph A.23. (Appendix A to this annex), the softening temperature shall be at least 90 C, and the melting temperature at least 100 C. The increased softening temperature requirement to 100 C is in consideration of the high temperatures generated in Type 4 cylinders during fast filling. The melting temperature was eliminated as the ISO 306 standard Plastics -- Thermoplastic materials -- Determination of Vicat softening temperature (VST), does not determine the melting point Test pressure The minimum test pressure used in manufacture shall be 30 MPa 1,5 times working pressure; Changed to 1,5 times working pressure, to recognize the fact that other working pressures may be used Leak-before-break (LBB) assessment Types CNG-1, CNG-2 and CNG-3 cylinders shall demonstrate Leak-Before-Break (LBB) performance. The LBB performance test shall be carried out in accordance with paragraph A.6. (Appendix A to this annex). Demonstration of LBB performance is not required for cylinder designs that provide a fatigue life exceeding 45,000 pressure cycles when tested in accordance with paragraph A.13. (Appendix A to this annex). Two methods of LBB assessment are included for information in Appendix F to this annex. Reduced to only one method (performance test), by eliminating the calculation approach. The accuracy of the calculation approach could not be readily verified by Type Approval Authorities. 6.9 Fire Protection All cylinders shall be protected from fire with pressure relief devices. The cylinder, its materials, pressure relief devices and any added insulation or protective material shall be designed collectively to ensure adequate safety during fire conditions in the test specified in paragraph A.15. (Appendix A to this annex). Pressure relief devices shall be tested in accordance with paragraph A.24. (Appendix A to this annex). conform to ISO The new ISO standard provides a far more thorough test program for evaluating the longterm integrity and performance of pressure relief devices. 11

12 6.12. Exterior environmental protection The exterior of cylinders shall meet the requirements of the environmental test conditions of paragraph A.14. (Appendix A to this annex). Exterior protection may be provided by using any of the following: (a) A surface finish giving adequate protection (e.g. metal sprayed on aluminium, anodizing); or (b) The use of a suitable fibre and matrix material (e.g. carbon fibre in resin); or (c) A protective coating (e.g. organic coating, paint) that shall meet the requirements of paragraph A.9. (Appendix A to this annex). Any coatings applied to cylinders shall be such that the application process does not adversely affect the mechanical properties of the cylinder. The coating shall be designed to facilitate subsequent in service inspection and the manufacturer shall provide guidance on coating treatment during such inspection to ensure the continued integrity of the cylinder. Manufacturers are advised that an environmental performance test that evaluates the suitability of coating systems is provided in the informative Appendix H to this annex. The test in Appendix H has been moved into A.14 as a mandatory test. The mandatory use of the Appendix H test is primarily the result of in-service stress corrosion cracking failures of CNG cylinders reinforced with glass fibre composites Production examinations and tests General Production examinations and tests shall be carried out on all cylinders produced in a batch. Each cylinder shall be examined during manufacture and after completion by the following means: (a) Ultrasonic scanning (or demonstrated equivalent) of metallic cylinders and liners in accordance with BS 5045, Part 1 ISO , Annex B, or demonstrated equivalent method, to confirm that the maximum defect size present is smaller than the size specified in the design; Replaced the BS standard with an equivalent ISO standard Maximum defect size For type CNG-1, CNG-2 and CNG-3 designs, the maximum defect size at any location in the metal cylinder or metal liner that will not grow to a critical size within the specified service life shall be determined. The critical defect size is defined as the limiting through-wall (cylinder or liner) thickness defect that would allow stored gas to be discharged without rupturing the cylinder. Defect sizes for the rejection criteria for ultrasonic scanning, or equivalent shall be smaller than the maximum allowable defect sizes. For type CNG-2 and CNG-3 designs assume that there shall be no damage to composite due to any time-dependent mechanisms; the allowable defect size for NDE shall be determined by an appropriate method. Two such methods are such as that outlined in the informative Appendix F to this annex. Reduced to only one method (performance test), by eliminating the calculation approach, since the accuracy of the calculation approach could not be verified by the Type Approval Authorities Change of design 12

13 Table 6.1 Material design qualification test Bend properties and weld examinations have been eliminated as welding no longer a part of the Regulation. The Fracture mechanics have been removed from ISO as it has not been possible for Type Approval Authorities to verify the accuracy of calculations. Table 6.4 Cylinder design qualification tests 13

14 x x x The name of the A.14 test has been changed as it has now been replaced by the Environmental testt moved from Annex H. The A.24 PRD performance test has been replaced by referencing the use of the comprehensive performance tests for PRDs in the ISO standard. 14

15 Change of design table replaced by revised table below. 15

16 Table 6.7 Change of Design The revised table has been expanded to provide a wider range of change of design conditions that qualify for the use of reduced test requirements. The added conditions are: Metal cylinder material for a change of alloy type Thread when the thread pitch or type on the port has changed. 16

17 The Change in Manufacturing Process was removed, as it is believed that if the manufacturing process changes in any way, then it is a new cylinder design and must undergo full qualification testing. The revised table also includes the following added tests: Leak before Break (LBB) test Stress Rupture test Drop test The PRD performance test (A.24) was removed, as PRD designs must be separately qualified in accordance with ISO Type CNG-1 metal cylinders 7.1. General The design shall identify the maximum size of an allowable defect at any point in the cylinder which will not grow to a critical size within the specified retest period, or service life if no retest is specified, of a cylinder operating to the working pressure. Determination of leak-before-break (LBB) performance shall be done in accordance with the appropriate procedures defined in paragraph A.6. (Appendix A to this annex). Allowable defect size shall be determined in accordance with paragraph above. Cylinders designed in accordance with ISO 9809 and meeting all the requirements therein are only required to meet the materials test requirements of paragraph above and the design qualification test requirements of paragraph 7.5., except paragraphs and below. It was stated that ISO 9809 designs are acceptable for CNG service, provided they meet the materials and design test requirements in ISO Instead, it has been decided that the preferred approach is to give ISO 9809 designs exemptions from certain tests in ISO These exemptions are provided in clause 7.4 of the Regulation Manufacturing and production test requirements Non-destructive examination The following tests shall be carried out on each metallic cylinder: (a) Hardness test in accordance with paragraph A.8. (Appendix A to this annex); (b) Ultrasonic examination, in accordance with ISO , Annex B, BS 5045, Part 1, Annex I, or demonstrated equivalent NDT method, to ensure that the maximum defect size does not exceed the size specified in the design as determined in accordance with paragraph above. BS standard replaced with equivalent ISO standard Cylinder batch tests Batch testing shall be conducted on finished cylinders which are representative of normal production and are complete with identification marks. Two cylinders shall be randomly selected from each batch. If more cylinders are subjected to the tests than are required by this annex, all results shall be documented. Cylinders qualified in accordance with ISO , ISO , ISO or ISO 17

18 7866 are not required to perform the pressure cycling test described in paragraph A.13. (Appendix A to this annex). The following tests shall as a minimum be carried out on these. Cylinders designed to these 4 ISO standards provide pressure cycle lives that exceed the CNG cylinder service cycle test requirements in A.13, so they are exempted from this one test. Editorial. (c) Periodic pressure cycling test. Finished cylinders shall be pressure cycled in accordance with paragraph A.13. (Appendix A to this annex) at a test frequency defined as follows: (iv) Should more than 6 months have expired since the last batch of production. T, then a cylinder from the next batch of production shall be pressure cycle tested in order to maintain the reduced frequency of batch testing in (ii) or (iii) above. 8. Type CNG-2 hoop-wrapped cylinders Curing of thermosetting resins If a thermosetting resin is used, the resin shall be cured after filament winding. During the curing, the curing cycle (i.e. the time-temperature history) shall be documented. The curing temperature shall be controlled and shall not affect the material properties of the liner. The maximum curing temperature for cylinders with aluminium liners shall be below the time and temperature that adversely affect metal properties is 177 C. Eliminated the use of a specific temperature limit for curing when aluminium liners are involved, as different aluminium alloys will have different temperature limits Non-destructive examination Non-destructive examinations shall be carried out in accordance with a recognized ISO or an equivalent standard. The following tests shall be carried out on each metallic liner: (a) Hardness test in accordance with paragraph A.8. (Appendix A to this annex); (b) Ultrasonic examination, in accordance with ISO , Annex B BS 5045, Part 1, or demonstrated equivalent NDT method, to ensure that the maximum defect size does not exceed the size specified in the design. BS standard replaced with equivalent ISO standard Cylinder design qualification tests Acid environment Environmental test One cylinder shall be tested in accordance with paragraph A.14. (Appendix A to this annex) and meet the requirements therein. An optional environmental test is included in the informative Appendix H to this annex. The Environmental test in Annex H has replaced the Acid environment test that was in the Regulation. The Environmental test is a far more comprehensive test of road environments compared to the Acid environment test that is currently in the Regulation. The Environmental test was developed by the automotive industry due to ruptures of glass reinforced composite cylinders in CNG service by stress corrosion cracking High temperature creep test 18

19 In designs where the glass transition temperature of the resin does not exceed the maximum design material temperature by at least C, one cylinder shall be tested in accordance with paragraph A.18. (Appendix A to this annex) and meet the requirements therein. In ISO an absolute minimum temperature of 102 C has been established, because otherwise the maximum design material temperature could be established by the manufacturer at a relatively low temperature, with the result that it would be too easy to claim the glass transition temperature is exceeded by 20 C. 10. Type CNG-4 all-composite cylinders Manufacturing requirements Manufacturing requirements shall be in accordance with paragraph 8.3. above except that the curing temperature for thermosetting resins shall be at least 10 C below the softening temperature of the plastic liner. The requirement for the resin curing temperature to be less than the plastic softening temperature was eliminated, because if the curing temperature did affect the plastic liner integrity, then the hydrostatic proof test (required on every cylinder) would detect this problem Cylinder batch tests General (a) Batch materials test (iii) The softening melt temperature of the plastic liner shall be tested in accordance with paragraph A.23. (Appendix A to this annex), and meet the requirements of the design; The softening temperature is determined by ISO 306 Plastics -- Thermoplastic materials -- Determination of Vicat softening temperature (VST). There is no standard for determining the melt temperature - in polymers, a sharp melting point usually does not occur; instead a melting temperature range is observed on heating. Annex 3A - Appendix A Test methods A.1. Tensile tests, steel and aluminium A tensile test shall be carried out on the material taken from the cylindrical part of the finished cylinder using a rectangular test piece shaped in accordance with the method described in ISO 9809 for steel and ISO 7866 for aluminium. For cylinders with welded stainless steel liners, tensile tests shall be also carried out on material taken from the welds in accordance with the method described in paragraph 8.4. of EN The two faces of the test pieces representing the inside and outside surface of the cylinder shall not be machined. The tensile test shall be carried out in accordance with ISO The use of welded materials has already been removed from this Regulation. A.2. Impact test, steel cylinders and steel liners The impact test shall be carried out on the material taken from the cylindrical part of the finished cylinder on three test pieces in accordance with ISO The impact test pieces shall be taken in 19

20 the direction as required in Table 6.2 of Annex 3A from the wall of the cylinder. For cylinders with welded stainless steel liners, impact tests shall be also carried out on material taken from the weld in accordance with the method described in paragraph 8.6. of EN The notch shall be perpendicular to the face of the cylinder wall. For longitudinal tests the test piece shall be machined all over (on six faces), if the wall thickness does not permit a final test piece width of 10 mm, the width shall be as near as practicable to the nominal thickness of the cylinder wall. The test pieces taken in transverse direction shall be machined on four faces only, the inner and outer face of the cylinder wall unmachined. The use of welded materials has already been removed from this Regulation. A.6. Leak-Before-Break (LBB) performance test Three finished cylinders shall be pressure cycled between not more than 2 MPa and nort less than 1.5 times working pressure 30 MPa at a rate not to exceed 10 cycles per minute. All cylinders shall fail by leakage. Changed to 1,5 times working pressure, to recognize the fact that other working pressures may be used. A.7. Extreme temperature pressure cycling (b) Hydrostatically pressurized for 500 cycles times the specified service life in years between not more than 2 MPa and not less than 1.3 times working pressure 26 MPa at 65 C or higher and 95 per cent humidity; Changed to 1,3 times working pressure, to recognize the fact that other working pressures may be used. (d) Then pressurize from not more than 2 MPa to not less than working pressure 20 MPa for 500 cycles times the specified service life in years at -40 C or lower; Changed to working pressure, to recognize the fact that other working pressures may be used. A.9.1. Coating performance tests Coatings shall be evaluated using the following test methods, or using equivalent national standards. (a) Adhesion testing in accordance with ASTM D3359, ISO 4624 using Method A or B as applicable. The coating shall exhibit an adhesion rating of either 4A or 4B, as applicable; ISO 4624 was erroneously introduced as an ISO test method equivalent to ASTM D3359 it was found to not be equivalent, so the original use of ASTM D3359 has been returned. (c) Impact resistance in accordance with ASTM D2794 Test method for Resistance of Organic Coatings to the Effects of Rapid Deformation (Impact). The coating at room temperature shall pass a forward impact test of 18 J (160 in-lbs); Editorial. (d) Chemical resistance when tested in general accordance with ASTM D1308 Effect of Household Chemicals on Clear and Pigmented Organic Finishes. The tests shall be conducted using the Open Spot Test Method and 100 hour exposure to a 30 per cent sulfuric acid solution (battery acid with a specific gravity of 1.219) and 24 hours exposure to a polyalkalene glycol (e.g. brake fluid). There shall be no evidence of lifting, blistering or softening of the coating. The adhesion shall meet a rating of 3 when tested in accordance with ASTM D3359; 20

21 Editorial. (e) Minimum 1,000 hours exposure in accordance with ASTM G15453 Practice for Operating Light- and Water-Exposure Apparatus (Fluorescent W-Condensation Type) for Exposure of non-metallic Materials. There shall be no evidence of blistering, and adhesion shall meet a rating of 3 when tested in accordance with ASTM D3359 ISO The maximum gloss loss allowed is 20 per cent; ASTM replaced G53 with G154. (f) Minimum 500 hours exposure in accordance with ISO 9227 ASTM B117 Test Method of Salt Spray (Fog) Testing. Undercutting shall not exceed 2 3 mm at the scribe mark, there shall be no evidence of blistering, and adhesion shall meet a rating of 3 when tested in accordance with ASTM D3359; ISO equivalent of ASTM standard. (g) Resistance to chipping at room temperature using the ASTM D3170 Chipping Resistance of Coatings. The coating shall have a rating of 7A or better and there shall not be any exposure of the substrate. Editorial. A.9.2. Coating batch tests (b) Coating adhesion The coating adhesion strength shall be measured in accordance with ASTM 3359ISO 4624, and shall have a minimum rating of 4 when measured using either Test Method A or B, as appropriate. ISO 4624 was erroneously introduced as an ISO test method equivalent to ASTM D3359 the original use of ASTM D3359 has therefore been returned. A.10. Leak test Type CNG-4 designs shall be leak tested using the following procedure (or an acceptable alternative); (b) Any leakage detected measured at any point that exceeds standard cm 3 /hr shall be cause for rejection. Leakage is the release of gas through a crack, pore, un-bond or similar defect. Permeation through the wall in conformance to A.21 is not considered to be leakage. The value specified for excessive leakage could not be readily be measured, so it was left up to the approval agencies to determine the amount of leakage depending on the technique that was used. It was also clarified that permeated gas did not constitute leakage. A.12. Hydrostatic pressure burst test (a) The rate of pressurisation shall not exceed 1.4 MPa per second (200 psi/second) at pressures in excess of 80 per cent of the design burst pressure. If the rate of pressurisation at pressures in excess of 80 per cent of the design burst pressure exceeds 350 kpa/second (50 psi/second), then either the cylinder shall be placed schematically between the pressure source and the pressure measurement device, or there shall be a 5 second hold at the minimum design burst pressure; Editorial. 21

22 (b) The minimum required (calculated) burst pressure shall be at least the minimum burst pressure specified for the design 45 MPa, and in no case less than the value necessary to meet the stress ratio requirements. Actual burst pressure shall be recorded. Rupture may occur in either the cylindrical region or the dome region of the cylinder. Changed 45 MPa to minimum burst pressure specified for the design, to recognize the fact that different designs may have different burst pressures. A.13. Ambient temperature pressure cycling (b) Cycle the pressure in the cylinder between not more than 2 MPa and not less than 1,3 times working pressure26 MPa at a rate not to exceed 10 cycles per minute. Changed to 1,3 times working pressure, to recognize the fact that other working pressures may be used. A.14. Acid eenvironmental test On a finished cylinder the following test procedure should be applied: (a) Exposing a 150 mm diameter area on the cylinder surface for 100 hours to a 30 per cent sulfuric acid solution (battery acid with a specific gravity of 1.219) while the cylinder is held at 26 MPa; (b) The cylinder shall then be burst in accordance with the procedure defined in paragraph A.12. above and provide a burst pressure that exceeds 85 per cent of the minimum design burst pressure. (replace with the Environmental test in Appendix H of Annex 3A) The Environmental test in Annex H is far more comprehensive test of road environments compared to the Acid environment test that is currently in the Regulation. The Environmental test was developed by the automotive industry due to ruptures of glass reinforced composite cylinders in CNG service by stress corrosion cracking. A.15. A Bonfire test General test requirements Cylinders shall be pressurized with natural gas and tested in the horizontal position at both: (a) Working pressure; (b) 25 per cent of the working pressure (only if a thermally-activated pressure relief device is not part of the design). Testing at 25% of working pressure is not required when a thermally-activated pressure relief device is used, as they function independently from the pressure in the cylinder. A.16. Penetration tests A cylinder pressurised to 20 MPa working pressure ± 1 MPa with compressed gas shall be penetrated by an armour piercing bullet with a diameter of 7,62 mm or greater. The bullet shall completely penetrate at least one side wall of the cylinder. For type CNG-1 designs, the projectile shall impact the side wall at 90. For type CNG-2, CNG-3 and CNG-4 designs, the projectile shall impact the side wall at an approximate angle of 45. The cylinder shall reveal no evidence of fragmentation failure. Loss of small pieces of material, each not weighing more than 45 grams, shall not constitute failure of the test. The approximate size of entrance and exit openings and their locations shall be recorded. 22

23 Changed 20 MPa to working pressure, to recognize the fact that other working pressures may be used. Changed impact angle for Type CNG-1 designs to 90 degrees (perpendicular), as it was found that armour-piercing bullets will ricochet when impacting steel cylinders at 45 degree angle. A.17. Composite flaw tolerance tests For type CNG-2, CNG-3 and CNG-4 designs only, one finished cylinder, complete with protective coating, shall have flaws in the longitudinal direction cut into the composite. The flaws shall be greater than the visual inspection limits as specified by the manufacturer. As a minimum, one flaw shall be 25 mm long and 1.25 mm in depth, and another flaw shall be 200 mm long and 0.75 mm in depth, cut in the longitudinal direction into the cylinder sidewall. The flawed cylinder shall then be pressure cycled from not more than 2 MPa to not less than 26 MPa1,3 times working pressure for 3,000 cycles, followed by an additional 12,000 cycles at ambient temperature; The cylinder shall not leak or rupture within the first 3,000 cycles, but may fail by leakage during the last 12,000 further design lifetime in years cycles (less the cycles already performed). cycles. All cylinders which[sj3] complete this test shall be destroyed. Changed to 1,3 times working pressure, to recognize the fact that other working pressures may be used. Replaced the 12,000 cycles as this value would then limit the design lifetime to 15 years, while the number of cycles should be a function of the lifetime of the design, which may not be 15 years. A.18. High temperature creep test (a) The cylinder shall be pressurised to 26 MPa 1.3 times working pressure and held at a temperature of 100 C for not less than 200 hours; Changed to 1,3 times working pressure, to recognize the fact that other working pressures may be used. (b) Following the test, the cylinder shall meet the requirements of the hydrostatic expansion test A.11., the leak test A.10. (for Type CNG-4 cylinders only), and the burst test A.12. above. Clarification that the Leak test only applies to Type 4 designs. A.19. Accelerated stress rupture test For type CNG-2, CNG-3, and CNG-4 designs only, one cylinder free of protective coating shall be hydrostatically pressurised to 26 MPa 1.3 times working pressure while immersed in water at 65 C. The cylinder shall be held at this pressure and temperature for 1,000 hours. The cylinder shall then be pressured to burst in accordance with the procedure defined in paragraph A.12. above except that the burst pressure shall exceed 85 per cent of the minimum design burst pressure. Changed to 1,3 times working pressure, to recognize the fact that other working pressures may be used. A.20. Impact damage test One[FM4] or more finished cylinders shall be drop tested at ambient temperature without internal pressurisation or attached valves. The surface onto which the cylinders are dropped shall be a smooth, horizontal concrete pad or flooring. One cylinder shall be dropped in a horizontal position with the bottom 1.8 m above the surface onto which it is dropped. One cylinder shall be dropped vertically on each end at a sufficient height above the floor or pad so that the potential energy is 488 J, but in no 23