Nova-Tech Pulsafeeder 5-Function Valve - Manual (Page 2)

L9403700-000 Revision F
2
5-FUNCTION VALVE OPERATIONS:
Pressure Relief Function (PRV):
Designed to relieve excessive pump discharge pressure (approximately 50% above PRV
rating). PRV is functional anytime the bottom control knob is turned to the letter “C”, also
labeled “PUMP” position.
Color code for PRV Rating:
Black........40-psi Spring part #L1104400-000
Blue.......100-psi Spring part #L1104500-000
Green.....150-psi Spring part #L1104600-000
Red........250-psi Spring part #L1104700-000
1. Back Pressure Function:
The back pressure function allows the pump to meter to atmosphere by creating a
discharge restriction of approximately 20-psi. Back pressure is provided anytime the top
knob is turned to “A”, also labeled “ON” position. Note: The back pressure function is
not intended to prevent flow-through from elevated supply tanks. The pumps’ rated
pressure does not have to be de-rated when the back pressure knob is in the “ON”
position.
2. Anti-Siphon Function:
The anti-siphon function prevents siphoning through the pump when pumping to a
receptacle lower than the pump. This feature is active when the top knob is turned to
the letter “A”, also labeled “ON” position.
3. Pump head Air Bleed Function:
This function is used when starting the pump to aid in priming. It allows for removal of
air from the pump head by bypassing air and fluid out the “RETURN” connection. This
feature will function when the bottom knob is turned to the letter “D”, also labeled
“BLEED” position.
4. Discharge Drain Function:
This function is used to depressurize and/or drain the pump discharge line. This is
accomplished by turning the top knob to the “B”, also labeled “OFF” position, and the
bottom knob to the “D”, also labeled “BLEED” position. This will bypass the discharge
line fluid through the “RETURN” line of the 5-Function Valve.
Maintenance:
The only maintenance required is to replace the diaphragms whenever the pump head
diaphragm is replaced. Sometimes when pumping dirty fluids, solids may become trapped
between the PRV diaphragm (bottom one) and the PRV seat. This may cause the PRV to
weep slightly. This is easily remedied by removing the diaphragm and wiping it with a cloth
and reinstalling it, if the damage is excessive, the diaphragm must be replaced.