scope:

Description

This standard applies to two types of backflow prevention assemblies identified as: 

Reduced Pressure Principle Backflow Preventers (RP); and 

Reduced Pressure Principle Fire Protection Backflow Preventers (RPF).

These assemblies consist of two (2) independently-acting check valves, internally force loaded to a normally closed position and separated by an intermediate chamber (or zone) in which there is a hydraulically operated relief means for venting to atmosphere, internally force loaded to a normally open position. These assemblies are designed to operate under continuous pressure conditions. The assembly shall include two (2) properly located, tightly closing shut-off valves per Section 1.3.2.7; and properly located test cocks per Section 1.3.2.5.

This standard also applies to Manifold Reduced Pressure Principle Backflow Assemblies consisting of two or more complete Reduced Pressure Principle Backflow Preventers in parallel. The assemblies do not need to be of the same pipe size. The manifold size shall be identified by the single inlet and outlet of the manifold reduced pressure principal backflow assembly. Manifold Reduced Pressure Principle Backflow Assemblies shall include line-sized shut-off valves on each inlet and outlet of the assemblies making up the manifold.

Size Range

Connection pipe sizes shall be in accordance with Table 1.

Pressure Range

An RP assembly shall be designed for a working pressure of at least 150.0 psi (1034.3 kPa).

An RPF assembly shall be designed for a working pressure of at least 175.0 psi (1206.7 kPa).

Temperature Range

The assemblies shall be designed for a minimum temperature range of 33.0°F to 140.0°F (0.6°C to 60.0°C).