AWWA C511-17(R21) Reduced-Pressure Principle Backflow Prevention Assembly

This standard describes the reduced-pressure principle backflow prevention assembly for potable water applications. The assembly shall be capable of withstanding a working water pressure of at least 150 psi (1,034 kPa) without damage to working parts or impairment of function and for operation on hot- or cold-water lines. This standard describes hot- and cold-water reduced-pressure principle backflow prevention assemblies. Assemblies shall be designed to operate, at a minimum, at a temperature range of 33°F to 140°F (1°C to 60°C). Hot-water assemblies shall be designed to operate, at a minimum, in water at a temperature range of 33°F to 180°F (1°C to 82°C). A complete assembly consists of a mechanical, independently operating, hydraulically dependent relief valve located between two independently operating, internally loaded check valves that are located between two tightly closing resilient seated shutoff valves with four properly placed resilient-seated test cocks (see Sec. 4.3.1.3).