ISO 28921-2:2015 specifies requirements for the type testing of isolating valves for low-temperature applications to verify the performance of valves at a low temperature from ? 50 °C down to ? 196 °C. NOTE Nominal sizes (DN), nominal pipe sizes (NPS), nominal pressure (PN) and Classes are covered in ISO 28921-1. ISO 28921-2:2015 does not evaluate valve actuators unless they are integral part of the valve. Valves during testing can be operated manually or an actuator can be used during the testing. The effect of cold gas vapours during testing is taken into consideration in particular if the actuator is mounted directly over the test stand with the cold gases engulfing the actuator. ISO 28921-2:2015 does not apply to valves for cryogenic services, designed in accordance with ISO 21011, used with cryogenic vessels.
Tämän julkaisun valmistelusta Suomessa vastaa Metalliteollisuuden Standardisointiyhdistys ry, puh. 09 19 231 (vaihde).
Sisällysluettelo
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Test conditions
4.1 Valve selection
4.2 Testing criteria and selection of valve design
4.3 Requirements for test valve, direction for installation and conditions
4.4 Preparation for low temperature test
5 Low temperature testing requirements
5.1 Safety provisions
5.2 Cooling of the valve
5.3 Test gas
5.4 Equipment
6 Information to be supplied by the purchaser
Annex A Test procedure for type testing of valves at low temperature (normative)
Annex B Information to be supplied by the purchaser (informative)
Annex C Low-temperature type test record (informative)
ASME B31.3:2016
EN 13480-2:2017 Metallic industrial piping - Part 2: Materials
ISO 28921-1:2013 Industrial valves -- Isolating valves for low-temperature applications -- Part 1: Design, manufacturing and production testing
ASME B31.3:2016
EN 13480-2:2017 Metallic industrial piping - Part 2: Materials
ISO 28921-1:2013 Industrial valves -- Isolating valves for low-temperature applications -- Part 1: Design, manufacturing and production testing
ISO 5208:2015 Industrial valves -- Pressure testing of metallic valves