APTech AP72 - Manual (Page 3)

Operation Manual Vacuum Generators
i) For pneumatically actuated models this requires applying actuation pressure.
ii) For manually actuated models this requires turning the knob counter-clockwise.
2. Perform the following to shut off the vacuum using the AP71 and AP72 series.
a. Close the shut-off valve.
i)
For pneumatically actuated models, vent off the actuation pressure. Note that if
the nitrogen pressure on the inlet port is higher than the inlet pressure rating, the shut-
off valve may not close or may be forced open even with no actuation pressure.
ii) For manually actuated models, turn the knob fully clockwise.
3. The integrated check valve on AP71 and AP72 series prevents back flow through the inlet
port in case pressure on the vacuum or vent ports ever exceeds the inlet port pressure. The
check valve functions regardless of whether the integrated shut-off valve is opened or closed
and regardless of whether the unit has a constant bleed option. The check valve does not
prevent back flow from the vent port to the vacuum port.
4. For units with the constant bleed option, if nitrogen pressure is supplied to the inlet port, a
small hole bypassing the integrated shut-off valve will allow a continuous, small flow rate of
nitrogen to bleed through the module even when the integrated shut-off valve is closed.
Please contact the factory or your local representative to answer questions or for further
information.
Manual 15000003 Rev 2 Page 3 of 3