GB/T 34347-2017Periodic inspection and evaluation of cryogenic insulated cylinders (English PDF)

4.1 Inspection period

4.1.1 The period of periodic inspection of gas cylinders shall not exceed 3 years.

4.2 Inspection items

The inspection items of gas cylinders include external inspection, safety accessories inspection, valve and pipeline inspection, air tightness test, static evaporation rate testing.

4.3 Preparation for inspection

4.3.1 Review of technical archives

4.3.2 Record

4.3.2.1 Check and record the manufacturing marks and inspection marks, on the nameplate of the gas cylinders one by one. The records include the country of manufacture, the cylinder manufacturing license number, the name of the manufacturer, the cylinder number, the product standard number, the standard name, the year and month of manufacture, the nominal working pressure, the test pressure of the liner, the medium contained, the nominal volume, the maximum filling volume, the net weight of gas cylinder, the date of last inspection.

4.3.3 Disposal of in-cylinder medium

4.3.3.1 Appropriate methods shall be taken, to discharge the medium in the cylinder and properly handle it, under the conditions of ensuring safety, hygiene, non-polluting the environment.

4.3.3.2 For gas cylinders with unknown medium, valves that cannot be opened, safety accessories that fail, they shall be stored separately and properly disposed of.

4.3.4 Surface cleaning and accessory removal

4.5 Inspection of safety accessories, valve, pipeline

4.5.1 Inspection of safety accessories

4.5.1.1 The safety accessories of the gas cylinder include. pressure gauge, safety valve, bursting disc, level gauge. Safety accessories shall meet the relevant requirements of TSG RF001, TSG ZF003, GB/T 16918, national standards or industry standards. It shall select the products produced by manufacturing enterprises, that have obtained corresponding manufacturing licenses, according to regulations. The models, specifications, technical parameters shall be definite and clear.

4.5.1.5 Check the liquid level gauges one by one. It shall be judged as unqualified, if finding the following defects.

4.5.2 Valve and pipeline inspection

4.5.2.1 Visually inspect OR check the cylinder valves one by one by a magnifying glass of 5X ~ 10X. It shall be judged as unqualified, if finding the following defects.

4.5.3 Assembly of safety accessories and valves

4.5.3.1 After all the accessories, which are removed from the cylinder body, are inspected and qualified, the surface shall be treated accordingly, according to the special requirements of the medium contained; the assembly shall be carried out, according to the requirements of the instruction manual. The seals used in the assembly shall not have chemical reaction with the contained medium.

4.7 Static evaporation rate detection

The gas cylinders shall be tested for static evaporation rate one by one. The detection method shall be the gas mass flow meter method or the weighing method.

5.1 Inspection period

5.1.1 The period of periodic inspection of gas cylinders shall not exceed 3 years.

5.2 Inspection items

The inspection items of gas cylinders include external inspection, safety accessories inspection, valve and pipeline inspection (limited to the pipeline system within the gas cylinder product range), fixture inspection, air tightness test, static evaporation rate detection.

5.3 Preparation for inspection

5.4 External inspection

Carry out visual inspection OR use a magnifying glass of 5X ~ 10X to inspect the outer surface of the gas cylinders one by one. It shall be judged as unqualified, if there are following defects.

5.5.1 Inspection of safety accessories

5.5.3 Assembly of safety accessories and valves

All accessories, which are removed from the cylinder, shall be assembled, according to the requirements of the instruction manual, after passing the inspection, respectively.

The seals, which are used during assembly, must not react chemically with LNG.

5.6 Fixture inspection

For the inspection of fixtures, it shall be judged as unqualified, if the following defects are found.

5.7 Air tightness test

5.7.1 The assembled gas cylinders shall be tested for air tightness one by one.

5.8 Detection of static evaporation rate

Gas cylinders shall be tested for static evaporation rate one by one. The detection method shall be the gas mass flow meter method or the weighing method. The test method shall refer to the requirements of GB/T 18443.5.