Product Description Bermad Air/Vacuum Relief Valve 1/2″ Eliminates Negative Pressure in Subsurface Installations. Allows air into the dripperline zone when it is not operating. Releases the air on zone turn-on. Applications; Install in subsurface Techline zones Specifications; Maximum pressure: 140 psi 1/2″ male threaded connection Not required for on-surface installations Features/Benefits Eliminates vacuum that could draw contaminants into the piping system Non-corrosive Pressure Balanced float, free of distortion or callapse Special drip tight dynamic seal Exclusive kinetic design prevents floats from being blown shut Perfect sealing under system pressure as low as 0.1bar. **You will need a Female Compression Tee 16mm-1/2″-16mm per valve** Click for Product Data Sheet