RPZ valves

This section explains our approach to Reduced Pressure Zone (RPZ) valves. These are a device that protects against backflow, providing protection against the contamination of mains water supply.

Application Form

Where a RPZ valve assembly is to be installed by a non-approved contractor, we must be notified in advance by completing an application form and providing a plan of the proposed installation.



‘Approved Installation Method AIM-08-01’ provided by WRAS sets out the requirements for installation, on-site testing and maintenance.


Annual testing

We are required to monitor all RPZ valve installations in our water supply area. They must be tested and certificated on an annual basis, and we or another accredited tester can carry this out.

Advanced notification of the test due-date will be given. We can provide a quotation for the cost of the work.

Find out a full list of current accredited RPZ valve testers.