GB13076-91 Dissolved Acetylene Gas Cylinders Periodic Inspection and Assessment
GB（GuoBiao）13076-91 dissolved acetylene gas cylinders periodic inspection and assessment is the industry standard of the Peoples Republic of China, indicating the requirements and procedures of dissolved acetylene gas cylinder periodic inspection and assessment. This standard is applicable to periodic inspection and assessment of dissolved acetylene gas cylinders with various water capacities. The standard also applies to the periodic inspection and assessment of dissolved acetylene gas cylinders as reconditioned and/or recycled.
1. Scope
This Standard specifies the requirements, test methods, rules for periodic inspection and assessment of dissolved acetylene gas cylinders with water capacities from 40L to 900L; this standard also applies to periodic inspection and assessment of dissolved acetylene gas cylinder as reconditioned and/or recycled
2. Normative references
This standard refers to the following normative references:
GB5099.1-2014, Safety of pressure gas cylinders Part 1. General requirements
3. Terms and Definitions
For the purpose of this standard, the following terms and definitions apply:
3.1 Cylinder
The seamless pressure vessel used to store and transport gas and liquefied gas, which is composed of cylinder body, cylinder head, valve, protective device and container.
3.2 Dissolved Acetylene Gas Cylinder
The sealed container filled with acetylene dissolved in acetone.
3.3 Periodic Inspection
A process of checking the safety conditions and technical conditions of the cylinder on a regular basis.
3.4 Assessment
A process of conducting measurements and testing to determine the service life and suitability of the cylinder for further use.
4. Requirements
4.1 Cylinder regular inspection shall comply with the requirements of GB5099-1.
4.2 The external testing of the cylinder shall be carried out in accordance with the requirements of 4.4. If a defect or fault is found in the external testing, the gas shall be discharged and the pressure relief valve or safety valve checked as required.
4.3 The pressure test of the cylinder shall be carried out in accordance with the requirements of 5.4. If the pressure test result is not qualified, the cylinder shall be withdrawn from service and shall not be used again until the pressure test is qualified.
4.4 Wall thickness measurement of cylinders (when required) shall be carried out in accordance with the requirements of 4.7. The minimum measured wall thickness of the cylinders shall be not less than the minimum specified value.
4.5 Visual inspection of the safety device and other accessories shall be carried out in accordance with the requirements of 4.4.
4.6 Water content measurement of cylinders (when required) shall be carried out in accordance with the requirements of 4.7. The water content of the nonrefillable cylinders shall not be less than 0.2% by mass of the total water content; and the water content of the refillable cylinders shall not be more than 0.5% by mass of the total water content.
4.7 Leak test of cylinders shall be carried out in accordance with the requirements of 5.3. Any evidence of leakage or other defect shall be further tested in an appropriate manner.
4.8 Gas tightness test of cylinders shall be conducted in accordance with the requirements of 4.7.
5. Test methods
5.1 Visual inspection
5.1.1 Cylinder external inspection. The cylinder external shall be inspected for visible defects. The damage or defect shall be evaluated as per Table 1.
Table 1. Damage or Defect Evaluation
Inspection Very minor Minor Major Prohibited
Appearance Light scratches, Surface scratches or Operable deep scratches, Minor dents, No surface cracks, damage that does not result in leaks Operable deep dents or damage that may result in leaks Deep cracks, Unreparable severe damage, Structural fatigue
5.1.2 Inspection of safety device and other accessories. Valves, safety devices and other accessories attached to the cylinder shall be visually inspected for signs of leakage, damage and corrosion
5.2 Pressure test
5.2.1 Pressure test of the cylinder shall be performed in accordance with the requirements of GB5099.1. The pressure test shall be carried out at least once every five years.
5.2.2 Pressure test results shall be compared to the pressure specified in the cylinder specification, and any pressure loss of more than 10% shall be considered as a failure.
5.3 Leakage test
5.3.1 Leakage test shall be conducted in accordance with the requirements of GB5099.1.
5.3.2 The leakage test shall be performed on both the valve and the cylinder wall, and any leakage rate of more than 5.0 ml/min shall be considered as a failure.
5.4 Wall thickness measurement
Wall thickness measurement shall be conducted in accordance with the requirements of GB5099.1. The minimum allowable wall thickness shall be:
For cylinders with water capacity of 40L to 100L: Not less than 1.0mm.
For cylinders with water capacity of 101L to 900L: Not less than 1.5mm.
5.5 Water content measurement
Water content measurement shall be conducted in accordance with the requirements of GB5099.1. The minimum allowable water content shall be 0.2% by mass of the total water content for nonrefillable cylinders, and not more than 0.5% by mass of the total water content for refillable cylinders.
6. Assessment
6.1 Upon the completion of visual inspection of the cylinder and other components, pressure test and wall thickness measurement, the cylinder shall be evaluated in accordance with Table 2.
Table 2. Evaluation Criteria
Evaluation Category Meaning of Evaluation
Qualified Passed all the tests
Unqualified Failed at least one of the tests
Rejected Failed at two or more tests
6.2 If the cylinder is found to be unqualified but is still able to satisfy the safety requirements, it may be allowed to be reexamined.
7. Maintenance
7.1 The cylinder shall be in perfect condition after it is examined and assessed.
7.2 The cylinder shall be maintained and protected properly during maintenance:
(1) The cylinder shall be taken out off service if it is found to be worn, damaged, or corroded.
(2) The cylinder shall be kept in a dry and ventilated environment in order to avoid leakage due to rusting.
(3) The cylinder shall be maintained in its designated position in order to avoid any wrong orientation when it comes to use.
8. Marking
The cylinder shall be marked with the examination result, the last inspection date, and the symbol of the competent authority who have conducted the inspection.
