RPZ assemblies are:
- * Suitable for both above or below ground installation.
- * Horizontal install is required unless factory-configured for alternatives.
- * Protects against back-siphonage and back-pressure.
A RPZ Valve is regarded as suited to hazard applications where the result of backflow into the drinking water supply could result in considerable danger. They are considered effective largely because they prevent back pressure and back-siphonage due to their design and because they’re testable to ensure correct function.
RPZ Valves are frequently selected as opposed to an air gap because the head loss across the valve is much less.
These devices consist of a pair of independent check valves that have a pressure monitoring chamber in between. The chamber is held at a pressure that’s less than the water supply pressure but still sufficient to be useful. The lower pressure is maintained by a differentiating relief valve that reduces extra pressure in the chamber by discharging it to a drain. Four testers are placed to enable verification of correct functioning of the valve with a differentiating pressure gauge.
A pair of gate valves are included to enable testing and maintenance. Facilities that require continual water pressure need to install two RPZ Valves parallel to one another so that one is available to supply water while the other is tested. Discharged material from the relieving device is a sign that a check valve may be leaking beyond their shutoffs or the valve is malfunctioning. Some standard water use conditions might cause short periods of discharge.