Pressure Vacuum Breaker assemblies shall be in stalled to withstand pressure for long periods and to prevent backflow of contaminated water into the potable water system in backsiphonage conditions. The Pressure Vacuum Breaker assembly shall consist of a single spring loaded check valve which closes tightly when water flow through the assembly drops to zero, and a single air relief valve that opens to break the siphon when pressure drops to 1psi.
The assembly shall include two resilient seated shut-offs and two resilient seated test cocks, considered integral to the assembly. Assemblies must be factory backflow tested. The check valve and air inlet valve must be constructed to allow in-line servicing of the assembly. The valve body shall be constructed of bronze. The check, poppet and bonnet assembly shall be constructed of engineered plastic to protect the valve body from freeze damage. Pressure Vacuum Breaker assemblies shall be installed a minimum of 12" (300mm) above the highest downstream outlet, and the highest point in the downstream piping.
The assembly shall be rated to 150psi working pressure and water temperature from 32 degrees F to 140 degrees F. The assembly shall meet the specifications of the USC - FCCC & HR Manual. Pressure Vacuum Breaker assemblies shall be FEBCO® Series 765 or prior approved equal.