ISO 5208:2008 pdf download.Industrial valves - Pressure testing of metallic valves
I Scope
This International Standard specifies examinations and tests that a valve manufacturer needs to act upon in order to establish the integrity of the pressure boundary of an industrial metallic valve and to verify the degree of valve closure tightness and the structural adequacy of its closure mechanism. This International Standard is to be applied in conjunction with the specific requirements of a valve product standard to the extent cited by the product standard as a normative reference. Where requirements of a product standard differ from those given in this International Standard, the requirements of the product standard apply.
This International Standard does not cover safety aspects of pressure testing.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1 shell test
test at a pressure in excess of the cold working pressure (2.9) rating of a valve for the purpose of validating the soundness and strength of the valve pressure containing and retaining structures
NOTE These structures include valve-actuating mechanisms that have a direct connection to the valve internals subject to fluid test pressure within the valve proper.
2.2 closure test
pressure test for the purpose of validating leakage through a valve’s closure mechanism
2.3 test pressure
internal pressure (gauge), expressed in bar 1) to which the valve under test is subjected
NOTE Unless otherwise noted, gauge pressure is used throughout this International Standard.
2.7 DN, NPS, A
alphanumeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters DN or NPS followed by, or the letter A preceded by, a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connections
NOTE The number following DN or NPS or preceding A does not represent a measurable value and is not used for calculation purposes except where specified in a product standard.
2.8 PN or Class
alphanumeric designation for pressure-temperature rating that is common for components used in a piping system, used for reference purposes, comprising the letters “PN or Class" followed by a dimensionless number indirectly related to the pressure retaining capability as a function of temperature of the component
NOTE The number following“PN or Class" does not represent a measurable value and is not used for calculation purposes except where specified in a product standard. There is no definitive correlation that links PN designations to Class designations.ISO 5208 pdf download.