Reduced pressure zone valves

If you are planning to install a type BA device – Verifiable Backflow Preventer with
Reduced Pressure Zone (RPZ Valve) then you need to get permission from us
before you start.


RPZ valves - commissioning and site testing of Type BA Device


  • Commissioning and site testing of a Type BA Device (Reduced Pressure Zone valve) assembly must be carried out by a City & Guilds accredited tester who has been approved by the water supplier as competent to test Type BA Devices
  • testing must be carried out at intervals not exceeding 12 months
  • on completion of a site test, a test report certificate must be completed by the tester with copies submitted to the water supplier and the person responsible for the device
  • please note, Type BA Devices will only give backflow protection up to fluid category 4.


Frequently asked questions