ISO 5208:2015 pdf free
ISO 5208:2015 pdf free.Industrial valves一Pressure testing of metallic valves
broad category of seating surface materials that make up a pliable seat sealing combination, including elastomeric, polymeric, solid and semi-solid grease seals, either used in combination or used in conjunction with a mating metallic or ceramic component
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 a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connections
Note 1 to entry: The number following DN or NPS does not represent a measurable value and is not used for calculation purposes except where specified in a product standard.
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 1 to entry: 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.
maximum fluid pressure assigned to a valve for operation at a fluid temperature of -20 °C to 38 °C
Note 1 to entry: Valve pressure-temperature ratings are specified in product standards by reference to PN or Class designations.
limiting pressure difference across the upstream and downstream sides of the closure element seals when the valve is in the closed position
Note 1 to entry: While the standard is for this to be equal to the CWP there may be circumstances that dictate a lesser pressure difference.
The test equipment shall be of such a design, that it does not subject the valve to externally applied loads that may affect the results of the test. When end-clamping devices are used, the valve manufacturer shall be able to demonstrate that, during the valve closure test, they do not serve to reduce the resultant leakage. Valves designed for installation between flanges, e.g. wafer style check or butterfly valves, shall not have test equipment clamping forces applied that are so great as to bear upon the pressure test results.
When equipment such as volume loss detection devices are used, the manufacturer shall be capable of demonstrating equivalence of the system with the requirements of this International Standard.ISO 5208 pdf download.
