GB/T 18443.4-2010Testing method of performance for vacuum insulation cryogenic equipment - Part 4: Leak-outgassing rate measurement (English PDF)

Foreword

GB/T 18443 "Testing method of performance for vacuum insulation cryogenic equipment" is divided into 8 parts.

--- Part 1: Basic requirements;

--- Part 2: Vacuum degree measurement;

--- Part 3: Leak rate measurement;

--- Part 4: Leak-outgassing rate measurement;

--- Part 5: Static evaporation rate measurement;

--- Part 6: Heat-leak rate measurement;

--- Part 7: Holding time measurement;

--- Part 8: Volume measurement.

This part is Part 4 of GB/T 18443.

This part replaces GB/T 18443.4-2001 "Testing method of cryo-insulation pressure vessels - Leak and outgassing rate measurement".

Compared with GB/T 18443.4-2001, the main changes of this part are as follows.

--- The scope of application has been expanded from the leak-outgassing rate measurement of cryogenic insulation pressure vessels to the leak-outgassing rate measurement of vacuum insulated cryogenic pressure vessels, vacuum insulated cryogenic welded gas cylinders, vacuum insulated pipes and pipe fittings, and other vacuum insulated cryogenic equipment;

--- Some terms and definitions are added and modified;

--- The requirements for the duration of the test are added;

--- The indirect measurement method 2 is added;

--- The formats of test records and test reports are added.

Appendix A and Appendix B of this part are informative appendices.

1 Scope

This part of GB/T 18443 specifies the requirements of the test principle and method, test devices, equipment and instruments, test conditions and test preparations, test procedures, data processing, test records, and test reports for the measurement of interspace leak-outgassing rate of vacuum insulated cryogenic equipment.

This part applies to the measurement of interspace leak-outgassing rate of vacuum insulated cryogenic equipment, such as vacuum insulated cryogenic pressure vessels except for the storage and transportation of liquid hydrogen medium, vacuum insulated cryogenic welded gas cylinders, vacuum insulated pipes and pipe fittings; the measurement of other equipment can be implemented by reference.

2 Normative references

The provisions in the following documents become the provisions of this Part through reference in this Part of GB/T 18443. For the dated references, the subsequent amendments (excluding corrections) or revisions do not apply to this Part, however, parties who reach an agreement based on this Part are encouraged to study if the latest versions of these documents are applicable. For undated references, the latest edition of the referenced document applies to this Part.

GB/T 18443.1-2010 Testing method of performance for vacuum insulation cryogenic equipment - Part 1: Basic requirements

GB/T 18443.2 Testing method of performance for vacuum insulation cryogenic equipment - Part 2: Vacuum degree measurement

3 Terms and definitions

The terms and definitions established in GB/T 18443.1-2010, GB/T 18443.2, GB/T 18443.3 and the following apply to this part.

4 Test principle and method

4.1 Calculate the value of the leak-outgassing rate by measuring the change value of the static interspace vacuum degree within a certain time interval at room temperature.

4.2 The leak-outgassing rate measurement of vacuum interspace is divided into the direct measurement method and the indirect measurement method.

5 Test devices, equipment, and instruments

Test devices, equipment, and instruments shall comply with the provisions of 4.2 in GB/T 18443.1.

6 Test conditions and test preparation

Test conditions and test preparations shall comply with the provisions of GB/T 18443.1.

When the indirect measurement method is used, the following requirements shall also be met.

7 Test steps

8 Data processing

8.1 When using the direct measurement method to measure the leak-outgassing rate, calculate it according to formula (1).

8.2 When using the indirect measurement method 1 to measure the leak-outgassing rate, calculate it according to formula (2).

8.3 When using the indirect measurement method 2 to measure the leak-outgassing rate, calculate it according to the following formulas.

9 Test records and test reports

9.1 Please refer to Appendix A for the formats of the test records.

Appendix A (Informative) Leak-outgassing rate test record (direct method)

Refer to Table A.1 for the test record form of the leak-outgassing rate measured with the direct method. […]