This standard specifies the basic method and technical requirements for the periodical inspection and evaluation of steel gas cylinders for the on board storage of compressed natural gas (hereinafter referred to as steel cylinder).
This standard is applicable to the steel cylinders designed and manufactured according to GB 17258 with a nominal working pressure of 16MPa~20MPa, nominal volume of 30L~120L and working temperature of -50℃ ~60℃. It may also be taken as reference for steel cylinders with a nominal volume less than 30L or larger than 120L.
This standard is not applicable to the gas storage cylinders of compressed natural gas at the gas filling station or the composite cylinders.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments (excluding amending errors in the text) or revisions are not applied. However, the parties entering into agreement according to these specifications are encouraged to research whether the latest editions of these references are applied or not. For undated references, the latest edition of the normative document is applicable to these specifications.
GB 7144 Coloured Cylinder Mark for Gases
GB 8335 Special Threads for Gas Cylinders
GB/T 8336 Special Threads Gauges for Gas Cylinders
GB/T 9251 Method for Hydraulic Test of Gas Cylinders
GB 10878 Special Taps of Taper Threads for Gas Cylinders
GB 12135 Technological Specifications for Periodic Inspection Station of Gas Cylinders
GB/T 12137 Method for Leakage Test of Gas Cylinders
GB 15382 General Technique Specifications for Cylinder Valves
GB 17258 Steel Cylinders for the on-board of Compressed Natural Gas as a Fuel for Vehicles
GB 17926 Compressed Natural Gas Cylinder Valve for Vehicle
JB 4730 Nondestructive Testing of Pressure Vessels
No. 250 Principles for Gas Cylinder Safety Supervision issued by ZJJJG in December 2000
3 Inspection Organizations, Period and Items
3.1 Inspection organizations
The inspection organizations carry out periodic inspection for steel cylinders must meet the requirements of GB 12135 and approved by the boiler and pressure vessel safety supervision organ regulated by the state of China.
3.2 Inspection period
3.2.1 The first and second inspection of steel cylinders shall be carried out every three years; after the second inspection, the steel cylinders shall be inspected every two years; the steel cylinders of taxicab shall be inspected every two years and the valid period of the second inspection is a year.
3.2.2 If the steel cylinders are due for periodical inspection or are found with severe corrosion, damage and other defect that may affect the safe use, the owner shall timely hand over the steel cylinder and the corresponding license plate number to the inspection organization, and the inspection organization shall carry out the inspection or decide whether the undue steel cylinder shall be inspected in advance. The disassembly of the steel cylinders must be in charge by the organization specialized in the installation and alteration of steel cylinders on vehicles; the owner shall not disassemble the steel cylinders by himself or herself. If the steel cylinder and accessories of car damaged in an traffic accident shall be reused, the steel cylinder shall be inspected and be reused after passing the inspection.
3.2.3 The steel cylinders in stock or out of service for more than an inspection period shall be inspected before being put into service.
3.3 Inspection items
The periodic inspection items of steel cylinder include appearance inspection, acoustic inspection, cylinder neck thread inspection, internal inspection, non-destructive testing, weight and volume measurement, hydraulic test, internal drying, cylinder valve inspection and leakage test.
