A reduced pressure (RP) backflow prevention device
is a device used to protect the potable
water supply from contaminated water. An RP valve consists of an automatic pressure relief valve
in between two check valves
. The pressure relief valve opens to the atmosphere in the event of a reduction in the pressure differential between the first two chambers of the device.
The assembly is considered to provide redundant means of protection because: (1) check valves keep water flowing in one direction only, and; (2) the relief valve will operate in the event the supply pressure drops below atmospheric pressure.
Reduced pressure backflow preventers can be abbreviated RP, RPP (Reduced Pressure Principle) and RPZ (Reduced Pressure Zone). RP assemblies protect against backsiphonage and backpressure, and may be used where a potential hazard exists. RP valves can be found in commercial buildings, hospitals, and industrial applications.