Four-Function Valves (4-Fv) - Milton Roy Roytronic A Series Instruction Manual

3.4

Four-Function Valves (4-FV)

Your pump may be equipped with a 4-FV, or standard discharge valve. If your pump is
not equipped with a four-function valve and you feel it is needed in your application, it
can be purchased as an accessory. Contact your local LMI stocking distributor. The
features of a 4-FV are listed below.
1. Pressure Relief: If the discharge line is over pressurized, the valve opens sending solu-
2. Line Depressurization: Opening the relief knob provides line drain back to the supply
3. Anti-Syphon: Prevents syphoning when pumping solution downhill or into a vacuum.
4. Back Pressure: Supplies approximately 25 psi back pressure to prevent overpumping
4-FV prevents syphoning when
pumping downhill into
low or no pressure.
tion back to the supply tank.
tank.
when little or no system back pressure is present.
Typical Installations Requiring the Anti-Syphon
Feature of a Four-Function Valve
INSTALLATION
4-FV prevents syphoning when
pumping into a vacuum such as the
suction side of a recirculating pump.
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