Hotspot: prEN558 CEN Enquiry

Face-to-face and centre-to-face dimensions of metal valves for use in flanged pipe systems - PN and Class designated valves.

What is it? 

The attached document has now been issued to CEN members for voting and comments on its content. The draft standard specifies the face-to-face (FTF) and centre-to-face (CTF) dimensions for PN and Class designated metal valves used in flanged pipe systems.

The range of sizes and pressure designations to be covered by the updated standard is

• DN10 to DN2000
• Class 125 to Class 2500
• 5 to PN400.

If you have any comments on the draft standard please submit them to the BVAA secretariat by 30-10-20 in order that they can be collated and forwarded to BSI as part of the UK response to the CEN enquiry.

Why is it important? 

The existing standard is referenced by current EN product standards and so needs revising to keep it up to date. A revision of ISO 5752 which also covers face-to-face dimensions is currently in progress, but further advanced than EN 558. It is important that, as far as possible, EN 558 and ISO 5752 specify the same dimensions to reduce the amount of diversity amongst similar valve designs and promote increased standardisation of designs to allow interchangeability.  

It is also important to note that ISO 5752 does not cover control valves in its scope and so EN 558 is an important source of face-to-face and centre-to-face dimensions for this product group that needs to be updated.  

Supersedes

This is a revision of the existing standard EN558:2017 which will be superseded when the updated standard is published.

Published: 29th October 2020