PSG Dover WILDEN PRO-FLO P.025, Engineering, Operation & Maintenance, Page: 13 / 28

WIL-10090-E-08
Wilden
®
13
Suggested Installation, Operation, Maintenance and Troubleshooting
Troubleshooting
Pump will not run or runs slowly.
1.
Ensure that the air inlet pressure is at least 0.4 bar (5 psig)
above startup pressure and that the differential pressure (the
difference between air inlet and liquid discharge pressures) is not
less than 0.7 bar (10 psig).
2.
Check air inlet filter for debris (see SUGGESTED
INSTALLATION).
3.
Check for extreme air leakage (blow by) that would indicate
worn seals/bores in the air valve, pilot spool and main shaft.
4.
Disassemble pump and check for obstructions in the air
passageways or objects that would obstruct the movement of
internal parts.
5.
Check for sticking ball check valves. If material being pumped is
not compatible with pump elastomers, swelling may occur.
Replace ball check valves and seals with proper elastomers.
Also, as the check valve balls wear out, they become smaller
and can become stuck in the seats. In this case, replace balls
and seats.
Pump runs but little or no product flows.
1.
Check for pump cavitation; slow pump speed down to allow
thick material to flow into liquid chambers.
2.
Verify that vacuum required to lift liquid is not greater than
the vapor pressure of the material being pumped (cavitation).
3.
Verify that vacuum required to lift liquid is not greater than
the vapor pressure of the material being pumped (cavitation).
4.
Check for sticking ball check valves. If material being pumped is
not compatible with pump elastomers, swelling may occur.
Replace ball check valves and seats with proper elastomers.
Also, as the check valve balls wear out, they become smaller
and can become stuck in the seats. In this case, replace balls
and seats.
5.
Ensure that all suction connections are tight, especially lower valve
ball retainers.
Pump air valve freezes.
1. Check for excessive moisture in compressed air. Either install
a dryer or hot-air generator for compressed air. Alternatively,
a coalescing filter may be used to remove the water from the
compressed air in some applications.
Air bubbles in pump discharge.
1.
Check for ruptured diaphragm.
2.
Check tightness of outer pistons (refer to Section 7).
3.
Check tightness of fasteners and integrity of O-rings and
seals, especially at intake manifold.
4.
Ensure pipe connections are airtight.
Product comes out air exhaust.
1.
Check for diaphragm rupture.
2.
Check tightness of outer pistons to shaft.
Pump rattles.
1. Create false discharge head or suction lift.