Walchem EZ Series Instruction Manual page 18

3.7 MultiFunction Valve Operation
The MultiFunction Valve is optional on select E-Series pumps and replaces the standard Manual Air Vent Valve when
ordered. It integrates the air venting/bleeding functions with a back pressure, anti-siphon, and pressure relief valve.
For more detailed specifications of the MultiFunction Valve, see its separate instruction sheet at walchem.com.
Air Vent / Bleed Function
1. Open the air vent by turning the relief valve knob 90 degrees to the "AV" position.
2. Operate the pump until all of the air is purged and only liquid is discharged from the air vent drain.
3. Turn the relief valve knob back 90 degrees to the "RV" position to set pressure relief.
Pressure Relief
1. In the "RV" position, the diaphragm under the relief valve knob provides a safety relief if the discharge line
pressure gets too high.
Line Pressure Relief
1. By rotating both the Relief valve knob to "AV" and the back pressure valve knob to "PF", both the discharge line
and the pump head pressures are released out the air vent for full line pressure release.
Back Pressure / Anti-Siphon Valve
1. A spring-loaded diaphragm under the back pressure knob automatically adds approximately 36PSI (15 PSI
for low pressure versions) of back pressure to the discharge side of the pump when the knob is set to the "BP"
position.
2. The diaphragm also prevents siphoning of chemical through the pump.
CAUTION: Confirm that liquid is discharged from the air vent drain. If the liquid is not discharged, the pres-
sure may not be released. If this is the case, repeat the Pressure Relief procedure.
Back Pressure
Set
BV
BV
PF
PF
BV
15
Pressure Relief
Set
RV
RV
AV
RV
Back Pressure
Relieved
BV
PF
PF
PF
BV
Pressure Relief
Relieved
RV
AV
AV
AV
RV
AV