GB/T 17258-2022 English PDF (GBT17258-2022)
GB/T 17258-2022 English PDF (GBT17258-2022)
GB/T 17258-2022: Steel cylinders for the on-board storage of compressed natural gas as a fuel for automotive vehicles
NATIONAL STANDARD OF THE
PEOPLE REPUBLIC OF CHINA
CCS J 74
Replacing GB/T 17258-2011
Steel Cylinders for the On-board Storage of Compressed
Natural Gas as a Fuel for Automotive Vehicles
(ISO 11439:2013, Gas Cylinders - High Pressure Cylinders for the On-board Storage of Natural Gas as a Fuel for Automotive Vehicles, NEQ)
ISSUED ON: OCTOBER 12, 2022
IMPLEMENTED ON: MAY 1, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of the PEOPLE Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative References ... 5
3 Terms, Definitions and Symbols ... 6
4 Types and Parameters ... 8
5 Technical Requirements ... 9
6 Test Methods ... 15
7 Inspection Rules ... 22
8 Marking, Coating, Packaging, Transportation and Storage ... 31
9 Installation ... 34
10 Certificate of Conformity and Batch Inspection Quality Certificate ... 34 Appendix A (normative) Hydrogen Sulfide Stress Corrosion Test ... 36
Appendix B (informative) Determination Method for Maximum Allowable Defect Size for Non-destructive Evaluation (NDE) ... 38
Appendix C (normative) Ultrasonic Testing ... 39
Appendix D (normative) Flattening Test Method ... 44
Appendix E (informative) Batch Inspection Quality Certificate of Steel Cylinders for the On-board Storage of Compressed Natural Gas as a Fuel for Automotive Vehicles48 Bibliography ... 51
Steel Cylinders for the On-board Storage of Compressed
Natural Gas as a Fuel for Automotive Vehicles
This document specifies the types and parameters, technical requirements, test methods, inspection rules, marking, coating, packaging, transportation and storage requirements of steel cylinders for the on-board storage of compressed natural gas as a fuel for automotive vehicles (hereinafter referred to as ?€?steel cylinders?€?).
This document is applicable to the design and manufacturing of steel cylinders with a nominal operating pressure of 20 MPa and 25 MPa, a nominal volume of 30 L ~ 300 L, an operating temperature of ?€?40 ???C ~ 65 ???C and a design service life of 15 years. The steel cylinders manufactured in accordance with this document are only used as the storage containers fixed on automotive vehicles and filled with compressed natural gas as automobile fuels that complies with GB 18047; additional loads caused by external forces, etc. are not included in the service conditions.
This document does not apply to gas storage steel cylinders used at compressed natural gas filling stations, nor does it apply to steel cylinders of welded structure. 2 Normative References
The contents of the following documents constitute indispensable clauses of this document through the normative references in this text. In terms of references with a specified date, only versions with a specified date are applicable to this document. In terms of references without a specified date, the latest version (including all the modifications) is applicable to this document.
GB/T 192 General Purpose Metric Screw Threads - Basic Profile
GB/T 196 General Purpose Metric Screw Threads - Basic Dimensions
GB/T 4157 Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking and Stress Corrosion Cracking in H2S Environment
GB/T 4336 Carbon and Low-alloy Steel - Dimension of Multi-element Contents - Spark Discharge Atomic Emission Spectrometric Method (routine method)
GB/T 5777 Automated Full Peripheral Ultrasonic Testing of Seamless and Welded (except submerged arc-welded) Steel Tubes for the Detection of Longitudinal and / or Transverse S1---the design wall thickness at the center of the bottom of the steel cylinder, expressed in (mm); S2---the design wall thickness of the grounding point at the concave bottom of the steel cylinder, expressed in (mm).
Figure 2 -- Types of End Structure
126.96.36.199 There shall be a transition section between the annular shell at concave end of the steel cylinder and the cylinder body, and the connection between the transition section and the cylinder body shall be smooth.
5.3.4 Design of cylinder mouth
188.8.131.52 The thread of the cylinder mouth shall adopt tapered thread, which shall comply with the stipulations of GB/T 8335 or relevant standards, and the number of effective threads shall not be less than 8.
184.108.40.206 The thickness of the cylinder mouth shall have sufficient strength; the mouth shall not be plastically deformed when bearing the torque of the upper valve and the additional external force of the riveted neck ring.
220.127.116.11 The cylinder valve shall comply with the stipulations of GB/T 17926 and shall be equipped with a safety pressure relief device.
18.104.22.168 The nominal burst pressure of the rupture disc is the hydrostatic test pressure, and the allowable deviation is ???10%0 ; the operating temperature of the fusible plug is 110 ???C ??? 5 ???C. 22.214.171.124 The rated discharge capacity of the safety pressure relief device shall be calculated in accordance with GB/T 33215 and shall not be less than the safe discharge capacity of the gas cylinder. In addition, it shall be ensured that the gas cylinder passes the fire burning test specified in 6.15.
5.3.6 Maximum allowable defect size for non-destructive evaluation (NDE) The maximum allowable defect size at any point of the steel cylinder shall be specified, so as to prevent failure of the steel cylinder due to leakage or rupture during its service life. The method of determining the maximum allowable defect size is shown in Appendix B. 5.4 Manufacture
5.4.1 General requirements
126.96.36.199 In addition to the stipulations of this document, the manufacture of steel cylinders shall also comply with the stipulations of product drawings and relevant standards. 188.8.131.52 The body of the steel cylinders is generally manufactured through the following methods:
a) Use steel billets, steel ingots and steel rods as the raw materials, and manufacture through extrusion, stretching or spinning, thinning and mouth-closing;
b) Use seamless steel pipes as the raw materials, and manufacture through bottom- closing and mouth-closing;
c) Use steel plates as the raw materials, and manufacture through stamping, stretching or spinning, thinning and mouth-closing.
184.108.40.206 During the bottom-closing and forming process of tubular gas cylinders, metal shall not be added, and welding shall not be performed.
220.127.116.11 The manufacture of the steel cylinders shall be managed in batches. In accordance with the sequence of heat treatment, no more than 200 cylinders, plus the number of cylinders used for destructive tests shall constitute one batch.
18.104.22.168 The depth of the concave end of the steel cylinders shall comply with the specified design value; the thickness of the spherical shell and annular shell at the end shall comply with the design requirements.
22.214.171.124 The preform made of seamless steel pipes by spinning shall be subject to process evaluation; the inner surface of the end of the cylinder body shall not have visible concave holes, wrinkles, bumps and scales; the defects at the end are allowed to be removed, but the design thickness of the end shall be ensured; the cylinder body shall not be subject to welding repair. For the gas cylinders made of seamless steel pipes through bottom-closing, before mouth-closing, the bottom air-tight test shall be carried out one by one. 126.96.36.199 For the surface defects of the cylinder body, it is allowed to use special tools for grinding; after grinding, the requirements of 7.1.3 shall be met.
5.4.2 Heat treatment
188.8.131.52 The body of the steel cylinders shall be subject to heat treatment as a whole. The heat treatment shall be carried out in accordance with the process with assessed conformity. 184.108.40.206 Oil or water-based quenching agent can be used as the quenching medium. When the water-based quenching agent is used as the quenching medium, the cooling rate of the cylinder body in the medium shall not be greater than 80% of the cooling rate in water at 20 ???C.
5.4.3 Non-destructive evaluation
After heat treatment, the body of the steel cylinders shall be subject to non-destructive evaluation one by one.
5.4.4 Inner surface treatment of cylinder body
After the hydrostatic test, the body of the steel cylinders shall be subject to drying treatment on the inner surface.
220.127.116.11 Neck ring
If assembly is required, the assembly of the neck ring and the cylinder body shall not adopt the mode of welding.
18.104.22.168 Cylinder cap
If assembly is required, the cylinder cap shall adopt a detachable structure. 22.214.171.124 Thread of accessories
For accessories with threaded connections, the thread profiles, sizes and tolerances shall comply with the stipulations of GB/T 8335, GB/T 192, GB/T 196, GB/T 197 or GB/T 20668. 6 Test Methods
6.1 Wall Thickness and Manufacturing Tolerance
6.1.1 The wall thickness of the cylinder body shall be subject to the ultrasonic full-coverage wall thickness measurement in accordance with Appendix C.
6.1.2 The manufacturing tolerance of the cylinder body is inspected with standard measuring tools or special measuring tools and sample plates. The inspection items include the average outer diameter, roundness, perpendicularity and straightness of the cylinder body. 6.2 Bottom Air-tight Test
Adopt an appropriate test device to pressurize the central area of the inner surface of the bottom of the tubular cylinders; the pressurized area shall be at least 1/16 of the bottom area of the cylinder body, and the diameter of the pressurized area shall be at least 20 mm; the test medium can be clean air or nitrogen. After pressurizing to the test pressure of the air- tight test, during the pressure holding period, brush soap solution at the center of the outer surface of the bottom; hold the pressure for at least 1 min. During the pressure holding period, observe whether the central area of the bottom of the cylinder body leaks. 6.3 Inner and Outer Surfaces
Conduct visual inspection; ensure sufficient brightness in the inspection environment. When inspecting the inner surface, endoscopic lamps or endoscopes can be used. 6.8 Metallographic Test
6.8.1 The metallographic specimen can be cut from the cylinder body of the tensile test. The preparation, size and method of the specimen shall comply with GB/T 13298. 6.8.2 The evaluation of microstructure shall be carried out in accordance with GB/T 13320. 6.8.3 The depth of the decarburized layer shall comply with GB/T 224.
6.9 Non-destructive Evaluation
On-line automatic ultrasonic testing equipment shall be adopted for the evaluation, which shall be performed in accordance with Appendix C.
6.10 Hardness Testing
Hardness shall be tested online in accordance with GB/T 230.1 or GB/T 231.1. 6.11 Hydrostatic Test
In accordance with the external measurement method specified in GB/T 9251, carry out the hydrostatic test; the test pressure is 1.5P.
6.12 Air-tight Test
After passing the hydrostatic test, in accordance with the test method specified in GB/T 12137, conduct the air-tight test; the test pressure is P.
6.13 Hydrostatic Burst Test
6.13.1 The hydrostatic burst test shall be carried out in accordance with GB/T 15385. 6.13.2 The pressure rise rate of the hydrostatic burst test shall not exceed 0.5 MPa/s. 6.13.3 The pressure - time or pressure - water inflow curve shall be automatically drawn, so as to determine the yield pressure and burst pressure of the cylinder body. 6.14 Pressure Cycling Test
6.14.1 The pressure cycling test shall be carried out in accordance with GB/T 9252. 6.14.2 The upper limit of the cyclic pressure shall not be lower than the hydrostatic test pressure (Ph) of the gas cylinder; the lower limit of the cyclic pressure shall not be higher than 2 MPa; the pressure cycling rate shall not exceed 10 times/min.
6.15 Fire Burning Test
6.15.1 Placement of steel cylinder
The steel cylinder shall be horizontally placed, and the lower side of the cylinder body shall be about 100 mm above the fire source. Metal baffles shall be used to prevent flames from directly contacting the cylinder valve and the pressure relief device. The metal baffles shall not directly contact the pressure relief device and the cylinder valve. 6.15.2 Fire source
The length of the fire source is 1.65 m; the flame is evenly distributed. Within the length range of the fire source, the flame shall be able to touch the outer surfaces of the lower part and both sides of the steel cylinder.
6.15.3 Temperature and pressure measurement
At least 3 thermocouples shall be evenly arranged along the lower side of the steel cylinder, so as to monitor the surface temperature; the distance between them is not less than 0.75 m. Meanwhile, a pressure gauge for measuring and monitoring the pressure in the cylinder shall be configured. Use metal baffles to prevent the flame from directly contacting the thermocouples, or embed the thermocouples in a metal block whose side length is less than 25 mm. During the test, at an interval of no more than 30 s, the temperature of the thermocouples and the pressure in the steel cylinder shall be recorded once. 6.15.4 General test requirements
Use natural gas or air to pressurize the steel cylinder to the nominal operating pressure. During the fire burning test, measures shall be taken to prevent the sudden explosion of the steel cylinder. After ignition, the flame shall quickly spread a length of 1.65 m and surround the lower part and both sides of the steel cylinder. Within 5 min after ignition, at least one thermocouple shall indicate a temperature of 590 ???C, and it shall not be lower than this temperature during the subsequent test. For steel cylinders with a length not greater than 1.65 m, the central position shall be placed above the center of the fire source. For steel cylinders with a length greater than 1.65 m, place them in accordance with the following requirements:
a) If one end of the steel cylinder is equipped with a pressure relief device, the fire source starts at the other end of the steel cylinder;
b) If both ends of the steel cylinder are equipped with pressure relief devices, then, the fire source shall be at the center between the pressure relief devices; c) If the steel cylinder is protected by an additional insulation layer, two fire burning tests shall be carried out under the operating pressure: one with the center of the fire source in the middle of the length of the steel cylinder; one with another cylinder, so that the fire source starts at one of the two ends of the steel cylinder. 6.16 Gunshot Test
Use an armor-piercing bullet with a diameter of at least 7.62 mm to penetrate a steel cylinder 126.96.36.199 In accordance with the requirements of 6.11, carry out the hydrostatic test. Under the hydrostatic test pressure (Ph), the pressure holding time shall not be less than 30 s; the pointer of the pressure gauge shall not fall back, and the cylinder body shall not leak or be obviously deformed. The rate of residual volumetric deformation shall not be greater than 5%.
188.8.131.52 The hydrostatic test report shall include the measured water volume and mass of the steel cylinder. The values of the water volume and mass shall retain one decimal place. EXAMPLE: the measured value of water volume or mass is 100.675: the value of water volume is expressed as 100.6, and the value of mass is expressed as 100.7.
7.1.13 Air-tight test
The test pressure of the air-tight test shall be the nominal operating pressure; the pressure holding time shall not be less than 1 min. The cylinder body, cylinder valve, and the connection between the cylinder body and the cylinder valve shall not leak. If leakage occurs due to assembly, it is allowed to carry out the test again.
7.1.14 Hydrostatic burst test
184.108.40.206 Check the pressure - time or pressure - water inflow curve of the hydrostatic burst test; determine the measured yield pressure (Py) and the measured burst pressure (Pb) of the cylinder body, which shall comply with the following requirements:
a) Py ??? Ph/F;
b) Pb ??? 1.6 Ph.
220.127.116.11 After the burst of the body of the steel cylinder, there shall be no fragments; the burst opening shall be on the cylinder body; the breach crack shall not extend to the cylinder mouth; the shape and size of the breach on the cylinder body shall comply with the stipulations of Figure 8.
18.104.22.168 The main breach of the cylinder body shall be a plastic fracture, i.e., there shall be an obvious shear lip on the edge of the fracture, and there shall be no obvious metal defects on the fracture.
7.3 Batch Test
7.3.1 The batch test items shall satisfy the stipulations of Table 5.
7.3.2 One steel cylinder shall be randomly taken from each batch of steel cylinders for the determination of various performance indicators (including tensile test, impact test, cold bend test or flattening test) after the heat treatment of the cylinder body, and the steel cylinder shall be subject to end dissection.
7.3.3 One steel cylinder shall be randomly taken from each batch of steel cylinders for the hydrostatic burst test.
7.3.4 One steel cylinder shall be randomly taken from each batch of steel cylinders for the pressure cycling test, and the test frequency is as follows:
a) For the first time, take one steel cylinder from each batch for the pressure cycling test; the number of pressure cycles is not less than 15,000;
b) If 10 consecutive production batches belong to the same design family (i.e., similar materials and processes, and compliance with the limiting conditions of design alterations, see 7.2.3), and no leakage or rupture occurs after the number of pressure cycles in the above-mentioned a) test reaches at least 22,500 times, then, the frequency of the pressure cycling test can be reduced to one steel cylinder taken from every five production batches;
c) If 10 consecutive production batches belong to the same design family, and no leakage or rupture occurs after the number of pressure cycles in the above- mentioned a) test reaches at least 30,000 times, then, the frequency of the pressure cycling test can be reduced to one steel cylinder taken from every ten production batches;
d) If the interruption exceeds 3 months from the last pressure cycling test, then, the test frequency reduced in b) or c) above shall become invalid, and from the next production batch, one cylinder shall be taken from each production batch for the pressure cycling test, so as to re-establish the batch pressure cycling test frequency reduced in b) or c);
e) If the pressure cycling test with a reduced frequency does not comply with the number of pressure cycles (respectively, 22,500 and 30,000) required in test b) or c), then, it is necessary to repeat the batch pressure cycling test frequency in a) for at least 10 batches, so as to re-establish the batch pressure cycling test frequency reduced in b) or c).
If the pressure cycling test in the above a), b) or c) of the steel cylinders cannot satisfy the requirement of at least 15,000 times, then, it shall be handled in accordance with the program in 7.5, so as to find out the cause of failure and correct it. Then, take three steel cylinders from this batch and repeat the pressure cycling test. If any one of the steel cylinders fails to reach 15,000 times, then, the batch of steel cylinders shall be scrapped. 7.4 One-by-one Inspection
Each steel cylinder produced in the same batch shall be subject to one-by-one inspection. The ins...