This standard covers the reduced-pressure principle backflow prevention assembly. 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 covers hot and cold water reduced-pressure principle backflow prevention assemblies. All assemblies shall be designed to, at a minimum, operate at a temperature range of 33 degrees F to 140 degrees F (1 degree C to 60 degrees C). Hot water assemblies shall be designed to, at a minimum, operate in water at a temperature range of 33 degrees F to 180 degrees F (1 degree C to 82 degrees C). Requirements are given for the following topics: materials; general design; detailed design; workmanship; testing and uniformity; handling; and, packaging.