QED AutoPump AP-2, Operation Manual

Page: 43 / 111

Page 35
AP-2 Manual
Revision 7 - August, 2007
Chapter 4: Assembly & Installation
The pump rate can be increased slightly by increasing the air pressure to
the pump. However, under conditions with high inlet pressures and little
discharge resistance, some air may exit with the fluid. That would be due
to a brief residual pressure in the pump which discharges fluid (and air)
even after the exhaust valve is opened.
Under normal operating conditions, no air should exit the pump with the
fluid.
If the pump is moving air out the fluid discharge and this is undesirable, a
needle valve in the air line can be used. This reduces the air flow rate to
the pump and thus the pressure buildup in the pump. Alternately, reduce
the pressure going to the pump though the pressure regulator.