17
3.4
MultiFunction Valve Operation
The MultiFunction Valve is optional on select E-Class pumps and replaces the standard Manual
Air Vent Valve when ordered. It integrates the air venting/bleeding functions with a back
pressure and anti-siphon valve.
Air Vent / Bleed Function
1. Open the air vent by turning the air vent adjustment
knob counter-clockwise one to one and a half
turns.
2. Operate the pump until all of the air is purged and
only liquid is discharged from the air vent drain.
3. Turn the air vent adjustment knob clockwise until it
bottoms out and will not turn further.
Back Pressure / Anti-Siphon Valve
1. A spring-loaded diaphragm automatically adds
30PSI of back pressure to the discharge side of the
pump when the air vent adjustment knob is closed.
2. If back pressure is not observed, the pressure
release knob may be in the release position (the
knob is resting in its ‘up’ location). If this is the
case, turn the knob clockwise until it ‘clicks’ down
(approximately ¼ turn).
3. The diaphragm prevents siphoning of chemical
through the pump.
Pressure Release
1. Stop the pump operation.
2. Turn the pressure release knob clockwise until it ‘clicks’ into the release or ‘up’ location
(approximately ¼ turn). If the knob is turned too far, it will ‘click’ again return to the back
pressure or ‘down’ position. If this happens, keep turning the knob clockwise until it ‘clicks’ one
time in the release (‘up’) position. Note: To avoid damage, do not turn the knob counter-
clockwise.
3. Turn the air vent adjustment knob counter-clockwise one or one and a half turns to release the
pressure in the discharge tubing/piping through the air vent drain. The air vent drain should
always be plumbed back to the supply tank or to safe disposal. Do not submerge the air vent
drain tubing under chemical in the supply tank.
CAUTION:
Confirm that liquid is discharged from the air vent drain. If the liquid is not
discharged, the pressure may not be released. If this is the case, repeat the Pressure Release
procedure.
Air Vent
Drain
Pressure
release
knob
Liquid
Discharge
Port
Air Vent
Adjustment
Knob
Lock
Nut
