GB/T 18443.3-2010Testing method of performance for vacuum insulation cryogenic equipment - Part 3: Leak rate measurement (English PDF)

Foreword

GB/T 18443 Testing Method of Performance for Vacuum Insulation Cryogenic Equipment is divided into eight 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 is Part 3 of GB/T 18443.

This Part serves as a replacement of GB/T 18443.3-2001 Testing Method of Cryo-insulation Pressure Vessels - Leakage Measurement and GB/T 16775-1997 Test Methods for Leak Rate of Cryogenic Containers.

In comparison with GB/T 18443.3-2001, the main changes are as follows.

---The scope of application is extended from the leak rate measurement of low-temperature heat insulated pressure vessels to the leak rate measurement of vacuum insulated cryogenic equipment, such as. vacuum insulated cryogenic pressure vessels, vacuum insulated cryogenic welding gas cylinders and vacuum insulated cryogenic pipes and their pipe fittings, etc.

---Terms and definitions are added.

---The test method is modified from the previous "dynamic leak detection method and cumulative leak detection method" into "helium hood leak detection method and helium hood leak detection method by-passing";

---The re-detection requirements for the effective minimum detectable leak rate are added;

---The requirements for the format of test records are added. Appendix A and Appendix B of this Part are informative.

1 Scope

This Part of GB/T 18443 specifies the test principles and methods, test devices, equipment and instruments, test conditions and preparation, test procedures, data processing, test records and test reports of the leak rate measurement of vacuum insulated cryogenic equipment.

This Part is applicable to the leak rate measurement of vacuum insulated cryogenic equipment, such as. vacuum insulated cryogenic pressure vessels, vacuum insulated cryogenic welding gas cylinders and vacuum insulated pipes and their pipe fittings, except for liquid hydrogen storage and transportation media. The other equipment may take this as a reference.

2 Normative References

The clauses of the following documents become clauses of this Part through the reference in this Part of GB/T 18443. In terms of references with a specified date, all subsequent amendments (excluding errata content) or revisions do not apply to this Part. However, the various parties that reach an agreement in accordance with this Part are encouraged to explore whether the latest versions of these documents are applicable. In terms of references without a date, the latest versions apply 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

What is established in GB/T 18443.1-2010 and GB/T 18443.2, and the following terms and definitions are applicable to this Part.

4 Test Principles and Methods

5 Test Devices, Equipment and Instruments

The test devices, equipment and instruments shall comply with the stipulations of 4.2 in GB/T 18443.1, and satisfy the following requirements. […]

6 Test Conditions and Preparation

6.1 The basic test requirements shall comply with the stipulations of GB/T 18443.1 and satisfy the following requirements. […]

7 Test Procedures

8 Data Processing

8.1 The effective minimum detectable leak rate of the instrument shall be calculated in accordance with Formula (1).

8.3 The leak rate of the measured piece shall be calculated in accordance with Formula (3).

9 Test Records and Reports

9.1 The format of test records is shown in Appendix A.

Appendix A (informative)

Test Records of Leak Rate The format of the test records of leak rate is shown in Table A.1. […]