Anti-Syphon Valve
The Tri-Purpose Valve can be installed as an anti-syphon valve to prevent syphoning fluid through a metering pump or other feeding system where the liquid is being fed into negative pressure. The greater the negative pressure, the tighter the diaphragm seats. Install with the flow directionas shown on data plate on base of valve.
Back Pressure Valve
The Tri-Purpose Valve can also be installed so as to require a metering pump or other injection device to develop a positive pressure in order to feed through it.
The opening pressure is approximately 30-40 PSI which is useful for feeding or metering into an open tank or reservoir located at a level below the supply tank. As a back pressure valve, it should be installed so that the flow direction is the same as the direction of the flow when used as an antisyphon valve. See data plate on base of valve.
Pressure Relief Valve
The Tri-Purpose Valve is an excellent pressure relief valve which can be adjusted after installation to any desired pressure between 30 PSI (2.1 kg/cm2) and 125 PSI (8.8 kg/cm2).
When used as a pressure relief valve, the Tri-Purpose Valve is installed on the branch of a tee whose run is in the pressure line. Flow direction through the valve when used as a pressure relief valve is 180° opposite the anti-syphon and back pressure flow direction. See data plate on baseof valve.
For more information, please see 
Data Sheet
