scope:

Description

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

Double Check Backflow Prevention Assembly (DC); and

Double Check Fire Protection Backflow Prevention Assembly (DCF).

These assemblies consist of two (2) independently acting check valves, internally force loaded to a normally closed position, two (2) properly located tightly closing shut-off valves per Section 1.3.2.6 and properly located test cocks per Section 1.3.2.4. These assemblies are designed and constructed to operate under intermittent or continuous pressure conditions.

This standard also applies to Manifold Double Check Backflow Prevention Assemblies consisting of two or more complete Double Check Backflow Prevention Assemblies 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 assembly. Manifold Double Check Backflow Prevention 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.

Rated Pressure

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

A DCF 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).