GB/T 13927-2022 Industrial valves - Pressure testing
1 Scope
This document specifies the additional conditions, requirements, methods and acceptance criteria for pressure test of industrial valves.
This document is applicable to the pressure test of metallic valves.
Note: The use of this document is specified by the valve product standard.
It may serve as a reference for valves made other materials.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
shell test
test on valve shell with specified test fluid and test pressure
Note: Including the opening and closing driving mechanisms that are connected to the valve internals subject to fluid pressure within the valve proper.
3.2
closure test
test for sealing performance of the sealing pairs of valve discs with specified test fluid and test pressure
3.3
back seal test
test for sealing performance of the back seal of a valve with specified test fluid and test pressure
3.4
test pressure
gauge pressure of the test fluid to which the valve cavity under test is subjected
3.5
test fluid
pressurized liquid or gas filled into the valve cavity during the test
3.6
resilient seats
sealing pairs composed of non-metallic elastic materials in conjunction with non-metallic elastic materials, or non-metallic elastic materials in conjunction with metallic materials
Note: Materials of resilient seats include polymeric, solid and semi-solid grease seals (such as oil seal plug valves), ceramics, etc.
3.7
cold working pressure
CWP
maximum allowable pressure assigned to a valve shell for working at a working temperature of -20℃ to 38℃
Note: Maximum working pressure-temperature ratings are specified in valve product standards.
3.8
design differential pressure
maximum allowable pressure difference between the fluid at inlet and outlet ends when the valve is in the closed position
Note: Some structural valves may have a design differential pressure lower than the cold working pressure.
3.9
double block-and-bleed valve
valve with two isolation sealing pairs that, when in the closed position, controls bleeding of fluid from the cavity between the two sealing pairs, when the pressure of the cavity is released, the two sealing pairs can cut off and maintain seal at the same time
3.10
visually detectable leakage
leakage during a valve pressure test, either through or past a pressure boundary or sealing pair that is observed with normal vision
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Additional conditions for pressure test
4.1 Purchaser examination
4.2 Witness test
4.3 Selection of test items
5 Pressure test requirements
5.1 Safety instruction
5.2 Test location
5.3 Test equipment
5.4 Pressure measuring equipment
5.5 Shell surfaces
5.6 Test fluid
5.7 Test pressure
5.8 Pressure test items
5.9 Test pressure duration
6 Test methods
6.1 Shell test
6.2 Back seal test
6.3 Closure test
7 Test acceptance criteria
7.1 Shell test
7.2 Back seal test
7.3 Closure test
7.4 Certification of compliance
Annex A (Informative) Comparison of clause/subclause numbers between this document and ISO 5208:2015
Annex B (Normative) Equivalent nominal diameters
Table 1 Requirements for pressure test items
Table 2 Minimum duration for test pressure
Table 3 Closure test
Table 4 Maximum allowable leakage rate of closure test
Table A.1 Comparison of clause/subclause numbers between this document and ISO 5208:2015
Table B.1 Equivalent DN numbers
