What is rpz valve how it works?
A backflow device is also known as an RPZ valve. A reduced pressure zone device is a type of backflow prevention device used to protect water. RPZ Valves by Ultravalve Ltd. How a Reduced Pressure Principle (RPZ) Backflow Prevention Device Assembly Prevents. A Reduced Pressure Zone (RPZ) lets you know that the valve is working properly. That the way the RPZ valve works is that it is designed with a relief valve that opens if either of.