This standard describes the double check-valve 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 potable water lines.
This standard describes hot- and cold-water double check-valve backflow prevention assemblies. Assemblies shall be designed to operate, at a minimum, at a temperature range of 33°F–140°F (1°C–60°C). Hot-water assemblies shall be designed to operate, at a minimum, in water at a temperature range of 33°F–180°F (1°C–82°C).
A complete assembly consists of two internally loaded, independently operating check valves, located between two tightly closing resilient-seated shutoff valves, with four properly placed resilient-seated test cocks (see Sec. 4.3.1.3).