• Airgap
• Reduced Pressure Principle (RPA)       
• Double Check Valve (DCA)   
• Pressure Vacuum Breaker (PVB)
• Hose Bib Vacuum Breaker (HBVB)

The physical separation between free flowing discharge end of a potable water supply pipeline and an open or non-pressure receiving vessel. An “approved air gap” shall be at least double the diameter of the supply pipe measured vertically above the overflow rim of the vessel no case less than 1”(one).

Reduced pressure principle backflow assembly is an assembly containing two independently acting approved  check valves together with a hydraulically operating, mechanically  independent pressure differential relief valve located between the check valves and at the same time below the first check valve. This assembly also includes four properly located resilient seated test cocks and two tightly closing resilient seated shut off valves at each end of the assembly. This assembly is designed to protect against a non-health (pollutant) or a health hazard (contaminant). This assembly must be installed a minimum of 12” above grade and shall not be used for backflow protection of sewage or reclaimed water.

• Standard Details: G-669 RPA .50” TO 2.5”

Reduced pressure principle backflow assembly is an assembly containing two independently acting approved check valves together with a hydraulically operating, mechanically independent, pressure differential relief valve located between the check valves and at the same time below the first check valve. This assembly also includes four properly located resilient seated test cocks and two tightly closing resilient seated shut off valves at each end of the assembly. This assembly is designed to protect against a non-health (pollutant) or a health hazard (contaminant).This assembly must be installed a minimum of 12” above grade and shall not be used for backflow protection of sewage or reclaimed water.

• Standard Details: G-671 RPA 3” TO 10”

Pressure vacuum breaker assembly is composed of independently operating internally loaded check valve and a independently operating loaded air inlet valve located on the discharge side of the check valve. This assembly is equipped with two properly located resiliant test cocks and tightly closing resilient seated shut off valves attached at the end of the assembly. This assembly is designed to protect against a  non-health hazard (pollutant) or a health hazard (contaminant). This assembly must be installed 12” above the highest down stream outlet and does not protect against back pressure.

• Standard Details: G-684 PVB .5” TO 2”