Reduced pressure backflow prevention assembly
A reduced pressure (RP)
backflow prevention deviceis a device used to protect the potablewater supply from contaminated water. An RP valve consists of an automatic pressure relief valvein 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. [ [http://www.americanbackflow.com/catalog/pdf/hersey/hersey.model.6CM.pdf American Backflow Specialties, Hersey Meters, Model 6CM] , page 4, retrieved on April 8, 2008.]
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.
* Air gap
Pressure vacuum breaker
Double check valve
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