Performance Requirements for Reduced Pressure Detector Fire Protection Backflow Prevention Assemblies
|Publication Date:||1 August 2011|
This standard applies to the two types of assemblies, identified as:
(a) Reduced Pressure Detector Assembly (RPDA); and
(b) Reduced Pressure Detector Assembly Type II (RPDA-II).
The RPDA and RPDA-II 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 18.104.22.168 and properly located test cocks per Section 22.214.171.124. The assemblies also include a bypass line which provides a visual or audible indication of system leakage or unauthorized use of water.
This standard also applies to Manifold Reduced Pressure Detector Assemblies consisting of two (2) or more complete RPDA or RPDA-II 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 RPDA or RPDA-II 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.