Instruction manual

Vacuum Pump Models QV2 & QV5
4 P/N: 2002-0010 Rev 6
Gas Ballast Operation
The vacuum pump utilizes a feature allowing for the partial removal of
condensing gases in the vacuum pump. The gas ballast valve can be
operated in the following manner.
CAUTION: If there is a possibility that there is condensation or high
amounts of water in the system, install a vapor
condenser in the line.
 Before you begin to draw a vacuum, the pump must be operational
with the intake port closed and the gas ballast valve open until the
instrument has reached its operating temperature. This is done to
ensure that vapor does not condense inside of the pump.
NOTE: The gas ballast should be closed and the intake valve
should be open during typical operation.
 Running the pump with the gas ballast valve open typically causes a
slight noise increase as well as an increase in the amount of oil
vapor at the exhaust cap/oil-filler plug vent.
 When drawing condensing vapor for an extended period of time,
observe the oil level often and change it frequently as needed.
 After the evacuation has been completed, we recommend that you
allow the pump to run for a few minutes with the gas ballast valve
open and the intake closed. This allows any vapor condensed in the
oil to be removed.