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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 9252-2001 Method for cycling test of gas cylinders.
In addition to editorial changes, the following main technical changes have been made with respect to GB/T 9252-2001:
——The application scope of this standard is modified;
——Some normative references are added;
——Special terms related to this standard are defined;
——The flowchart for the testing apparatus is deleted;
——Basic requirements of the testing apparatus are modified and improved;
——Requirements for the use, installation and accuracy of measuring instruments are supplemented;
——The relevant provisions on the tested cylinder are deleted;
——The basic requirements for relevant tests are modified;
——The detailed rules and clauses that shall belong to the post operation method and test operation procedures are deleted;
——Relevant provisions on post test inspection are deleted;
——The contents of test records and reports are specified;
——Annex A of Edition 2001 is deleted;
——Annex B of Edition 2001 is deleted.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by and is under the jurisdiction of the National Technical Committee on Gas Cylinder of Standardization Administration of China (SAC/TC 31).
The previous edition of this standard is as follows:
——GB/T 9252-1988 and GB/T 9252-2001.
Method for pressure cycling test of gas cylinders
1 Scope
This standard specifies the basic requirements on the method and apparatus for pressure cycling test of gas cylinders.
This standard is applicable to pressure cycling test of gas cylinders with nominal working pressure not greater than 70MPa (gauge pressure, the same below).
This standard is not applicable to for filler-contained cylinders.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 13005 Terminology of gas cylinders
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 13005 and the following apply.
3.1
pressure cycling
in the pressure cycling test, a process that the pressure is completed in the order of boosting pressure to required upper pressure → maintaining pressure → decreasing pressure to required lower pressure → maintaining pressure is called a pressure cycling
3.2
cyclic pressure
the repeated alternating pressure values applied during the pressure cycling test, including the upper cycling pressure value and the lower cycling pressure value
3.3
required upper pressure
the upper cycling pressure value required in the pressure cycling test
3.4
required lower pressure
the lower cycling pressure value required in the pressure cycling test
3.5
holding time
the time that the pressure is kept constant at the upper and lower pressure in the process of pressure cycling
3.6
cyclic frequency
number of cycles per minute
Note: Generally, the cyclic frequency is calculated for 10 pressure cycling.
3.7
pressure cycling waveform
record curves of pressure changing with time in each pressure cycling
3.8
tested cylinder
gas cylinders to be tested or under test
3.9
testing apparatus
combination of pressure device, motor, relief valve, reversing valve, computer and other measurement and control systems, safety device, pressure pipeline, pressure and temperature measuring instruments, auxiliary equipment and other basic parts for pressure cycling testing of tested cylinders
3.10
testing system
combination of testing apparatus and tested cylinder
4 General requirements for testing apparatus
4.1 The pressure device of the tested cylinder may be hydraulic pump and other pressure devices.
4.2 The pressure device shall have good sealing performance and stable pressure boost rate, and its flow rate shall be adjustable to meet the needs of test cyclic frequency, and the flow rate shall be stable to keep each pressure cycling waveform consistent.
4.3 The pressure pipe shall be fixed and properly arranged, and the connection with measuring instruments and test systems shall be provided with good sealing performance.
4.4 The testing apparatus shall be provided with the function of adjusting and controlling the cyclic pressure, cyclic frequency, holding time and continuous pressure cycling within the specified range.
4.5 The testing apparatus shall display, record and save the pressure cycling waveform, number of cycles, maximum cyclic frequency, actual upper and lower pressure of each pressure cycling and the corresponding time automatically, accurately and in real time. All original test records stored in real time shall not be changed.
4.6 The deviation of the measured upper and lower pressure shall meet the requirements of the corresponding gas cylinder standards. If there is no provision in the gas cylinder standard, the deviation of the measured upper pressure shall not exceed the smaller value of +5% and 3MPa of the required upper pressure; the measured lower pressure shall not exceed the required lower pressure, but when the required lower pressure is 0, the deviation of the measured lower pressure shall be 0MPa-0.5 MPa.
4.7 The frequency of pressure data acquisition by the testing apparatus shall not be less than 500 times/s, and the cyclic pressure-time data of at least 20 pressure cycling shall be stored.
4.8 If data acquisition card is used for data acquisition such as pressure and temperature, the data acquisition card shall at least meet the following requirements: sampling frequency shall not be less than 100K, and resolution shall not be less than 12 bits. Data acquisition by other methods shall not be lower than the relevant requirements of the data acquisition card.
4.9 The testing apparatus shall be able to monitor the temperature of the test medium and the outer surface of the tested cylinder, and ensure that the temperature of the test medium and the outer surface of the tested cylinder is within the specified temperature range. The contact temperature measuring element for measuring the temperature of the outer surface of the tested cylinder shall be in good contact with the outer surface of the tested cylinder. When pressure cycling test in specific environment such as low temperature or high temperature is carried out, the testing system shall be matched with the corresponding test environment.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements for testing apparatus
5 Measuring instruments
6 Test Medium and test temperature
7 General requirements for test
8 Precautions to be taken during the test
9 Test record and report