R​PZ FAQs: General

How do I know if I need an RPZ valve?

RPZ valves, or BA devices, are a recognised form of backflow prevention offering protection against back pressure and back siphonage up to and including fluid category 4.

If a plumbing system in your premises has been categorised as fluid category 4 or less by your water undertaker, then an RPZ valve may be an appropriate form of point of use backflow protection. An RPZ valve may also be suitable for wholesite backflow protection. For further information consult the local water undertaker.

Please note: to show they are functioning satisfactorily all RPZ valves are required to be regularly tested by a competent RPZ tester. Test intervals are set by the local water undertaker. Whilst test intervals may vary, they will be at least annually.



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Uncontrolled if downloaded. This is informative, non-statutory guidance and intended for general guidance purposes only; it is subject to change.

Compliance with this information should not be relied upon as guaranteeing no enforcement action will be taken by water undertakers. Water Regs UK accepts no liability for loss, indirect or consequential loss arising from or in connection with this guidance document.