GB/T 9252-2017Method for pressure cycling test of gas cylinders (English PDF)

Foreword

This Standard was drafted as per the rules specified in GB/T 1.1-2009.

This Standard Replaced GB/T 9252-2001 Method for Cycling Test of Gas Cylinders.

Compared with GB/T 9252-2001, this Standard has the major technical changes besides editorial modifications.

--- Modify the applicable scope of the standard;

--- Add normative references;

--- Give definitions against the terminology involved in this Standard;

--- Delete testing apparatus flow chart;

--- Modify and improve the basic requirements for testing apparatus;

--- Supplement the requirements for use, installation, accuracy, and etc. of measuring instrument;

--- Delete the relevant provisions of the tested cylinder;

--- Modify the basic requirements for test;

--- Delete the terms and conditions that belongs to the post operating methods and test operating procedures;

--- Delete the relevant provisions of test after test;

--- Specify the test records and report contents;

--- Delete Appendix A in Edition 2001;

--- Delete Appendix B in Edition 2001.

1 Scope

This Standard specifies the method for pressure cycling test of gas cylinders, basic requirements for test device.

This Standard is applicable to the pressure cycling test of gas cylinders with nominal working pressure no greater than 70MPa (gauge pressure, the same below).

This Standard is inapplicable to the gas cylinders filled with stuffing.

2 Normative References

The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this document.

GB/T 13005 Terminology of Gas Cylinders

3 Terms and Definitions

The following terms and definitions and those ones stipulated in GB/T 13005 are applicable to this document.

4 Basic Requirements for Testing Apparatus

4.1 The pressure device of tested cylinder can select the hydraulic pump or other pressure devices.

4.2 The pressure device shall have good sealing performance and steady pressure increasing rate; its flow rate shall be adjusted to meet the requirements of test cyclic frequency; the flow rate shall also be stable to keep the waveforms of all pressure cycling consistent.

4.3 The pressure-bearing pipeline shall be fixedly installed and properly arranged; its connection with the measuring instrument and testing system shall have good sealing performance.

4.6 The upper and lower limit deviation of the actually-measured cyclic pressure shall conform to the provisions of the corresponding gas cylinder standard.

4.7 The acquisition frequency of the testing apparatus against the pressure data shall be no less than 500 times/s; and the cyclic pressure-time data for 20 times pressure cycling shall be stored.

4.9 The testing apparatus shall be capable of monitoring the temperature of test medium and outer surface of the tested cylinder; and guaranteeing the above temperature within specified range. The contact temperature measuring element that measures outer surface temperature of tested cylinder shall be in good contact with the outer surface of the tested cylinder. When taking the specific environmental pressure cycling test at low or high temperature, the testing system shall be adapted to the appropriate test environment.

4.13 The testing apparatus shall be equipped with auxiliary equipment such as cooling, filtering devices to keep the valve and pump running continuously.

4.14 The testing system shall take appropriate safety precautions to ensure the safety of operator sand equipment during the test.

5 Measuring Instrument

6 Test Medium and Test Temperature

6.1 The circulating medium used in the test shall be featured by suitable viscosity, stable performance, not damaging the fracture after the tested cylinder is cracked, and adapting to the testing apparatus required hydraulic oil, water or other non-corrosive liquids.

6.2 When taking the pressure cycling test at the normal temperature, the temperature of test medium and test environment shall be no less than 5°C; and the temperature on outer surface of the tested cylinder shall not exceed 50°C.

7 Basic Requirements for Test

7.1 Before the test, perform the pressure increasing and decreasing for several times below the nominal working pressure against the tested cylinder, so that the air in the testing system can be discharged as much as possible. Confirm the testing system is leak-free.

7.2 Set the required upper pressure, required lower pressure and holding time. The required upper pressure shall conform to the provisions of corresponding gas cylinder standards;

7.3 Cyclic frequency shall conform to the provisions of corresponding gas cylinder standards; if there is no provisions of gas cylinder standards, it shall not exceed 15 times/min.

8 Test Precautions

8.1 For larger tested cylinder, fillers such as aluminum block or rod can be filled into the cylinder before filing the test medium, so as to improve the pressure-increasing and pressure-decreasing rate. The filler and test medium shall not occur chemical action, and shall not generate impact or friction against the inner wall of cylinder as the pressure cycling.

8.2 In addition to the cyclic pressure and connecting pipe's action force against the cylinder mouth during the test, no additional force shall be imposed on the tested cylinder that may influence the stress state of the cylinder.

8.5 No one shall approach the testing system with pressure during the test.

8.6 In addition to use for the inspection related to the purpose of the test or for subsequent tests, the cylinder after taking the pressure cycling test shall be eliminated the functions of use.

9 Test Records and Reports

9.1 The relevant information and data during the test process shall be recorded as per the actual conditions of the cylinder pressure cycling test. After the completion of the test, the testing system can automatically generate test records; the test records shall take the picture, PDF and other document format that can't be changed. The test records shall be detailed, true, accurate and traceable. […]