We supply Double Orifice Air Relief Valve.The HISPEED® air vacuum valves are designed to discharge air during the filling or charging of the system and to admit air into the system during system drainage, valve or pump shut-off or at water column separation. We also offer a range of air release valves and combination air valves combining the functions of an air release valve and an air vacuum valve. The HISPEED® air vacuum valves are designed for installation in the water supply connection to sprinkler, deluge, foam systems, or standpipe fire protection systems.The HISPEED® air vacuum valve features a flange, easy installation and accessibility. We are expecting to become your long term partner in China.