RP-500-200 - 2" A.R.I. Reduce Pressure Assembly Backflow Preventer
The RP-500 Backflow Preventer is designed to supply maximum
protection against backflow caused by negative pressure or
backpressure. Backflow may cause infiltration of chemicals, fertilizers
and/or other pollutants into potable water systems. The RP-500 is reliable and easily maintained, without the need for special tools. The RP-500 is built with two independent, easily replaceable encapsulated spring-loaded check valves. A revolutionary, internal
Reduced Pressure Zone, located between the check valves, ensures protection and reliable performance of the relief valve.
During normal flow, the two check valves open to supply water
downstream. The Relief Valve is power-activated by upstream pressure and is kept shut by a diaphragm, through the internal control system. In the zone, the area between the check valves, pressure is maintained
at approximately 0.43 bar lower than the water supply pressure. The
Outlet Check Valve is spring-loaded to maintain a minimum pressure decrease of 0.07 bar. When negative pressure or sub-atmospheric conditions occur, the Inlet
Check Valve closes to prevent backflow. If the Outlet Check Valve
fails, the pressure between the two check valves rises, opening the Relief Valve and releasing the water to the atmosphere. The Relief Valve operates on differential pressure. Supply pressure on
the upstream side of the Inlet Check Valve acts against the diaphragm
to close the Relief Valve during normal operation. In the event of
backpressure or backsiphonage, the Relief Valve will open to maintain the pressure in the “zone” at 0.14 bar less than the inlet pressure.