Performance Requirements for Double Check Backflow Prevention Assemblies and Double Check Fire Protection Backflow Prevention Assemblies
|Publication Date:||1 August 2011|
This standard applies to two types of backflow prevention assemblies, identified as:
(a) Double Check Backflow Prevention Assembly (DC); and
(b) 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 22.214.171.124, and properly located test cocks, per Section 126.96.36.199. 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 (2) 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.
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)