BVAA Hot Spot ISO DIS 28921-1 Isolating Valves for Low-temperature Applications- Design Manufacture and Production Testing

What is it?

There has been a draft revision of ISO 28921-1:2017 Isolating valves for low-temperature applications — Part 1: Design, manufacturing and production testing has now been issued for DIS enquiry by ISO TC153 and is available for comment.

This document specifies the requirements for the design, manufacture and testing of gate, globe, ball/plug and butterfly valve types for use in low and cryogenic temperature service between −50 °C and −196°C. It covers isolating valves of sizes DN:10 -1 800 and pressure designations PN16 – 400 and Class 150 – 2500. This document excludes safety valves and control valves and it does not apply to valves for cryogenic services, designed in accordance with ISO 21011, which were recently covered in Hot Spot BV002368.

Why is it Important?

This revised standard extends the size range and pressure designations of the first edition, and clearly excludes control valves and safety valves from its scope. Annex A covering production testing has been updated and changes have also been made to the referenced type testing procedures covered by ISO 28921-2 which is also currently under revision.

This document has many similarities to ISO 21011 which is also under revision by ISO TC 220 and represents an opportunity to review the requirements of both standards to ensure that there is appropriate consistency between them. Consistency would prevent unnecessary variations in design and prevent repetitive testing to slightly different specifications. Current areas of inconsistency between the two documents are differences in testing requirements, mounting orientation and leakage rates.

Supersedes
It is intended that this second edition will cancel and replace ISO 28921-1:2013.

Continuous Improvement

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Please note: this Hotspot is for information purposes only. We invite comments from BVAA members only. Please also note that at time of publication ballots may be closed. For more information please contact the Secretariat: enquiry@bvaa.org.uk

Published: 28th May 2021