6
Instruction Manual
2.4 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 4-FV 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.
4-FV prevents syphoning when
pumping downhill into
low or no pressure.
4-FV prevents syphoning when
pumping into a vacuum such as the
suction side of recirculating pump.
1. Pressure Relief:
If the discharge line is over
pressurized, the valve opens sending solution
back to the supply tank.
2. Line Depressurization:
Opening the relief knob
provides line drain back to the supply tank.
3. Anti-Syphon:
Prevents syphoning when
pumping solution downhill or into a vacuum.
4. Back Pressure:
Supplies approximately 25 psi
back pressure to prevent over pumping when
little or no system back pressure is present.
Figure 5. Typical Installations Requiring the AntiSyphon
Feature of a Four-Function Valve
SECTION 2 - INSTALLATION
Summary of Contents for ROYTRONIC A Series
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