QED AutoPump AP-3, Operation Manual, Page: 71 / 119

QED Environmental Systems
AP-3 Manual
Page 62
8. Fluid Check Valves :
• Open the pump. Hold the pump vertically and pour water into the discharge check
valve. If water flows through, clean the valve.
• Remove the valve and use emery cloth or a very fine sand paper to polish the surface
where the ball seats.
• Inspect the ball for wear. If it is too small to seal on the seat, or if it is obviously out
of round, replace it with a new ball.
• If the pump is a Bottom-Loading design, inspect the seat of the bottom check valve
for debris and wear. Clean or replace if necessary.
• If the pump is a Top-Loading design, remove the fluid inlet check valve and inspect
the seating surface and the ball for debris and wear.
9. Air Inlet Valve Timing :
• Remove the pump casing. Connect the air supply. Pull the control rod down to the
bottom of its travel. Slowly raise the rod towards the pump head. Air should begin to
flow through the valve when the lever is horizontal.