8
5.7 Venting
A vent screw is located on the pump reservoir. Before using the
pump, loosen the vent screw one full turn to open the vent. See
Figure 8.
NOTICE
Reservoir must be vented during pump operation.
Failure to open the vent may result in cavitation and damage to
pump components.
The vent should also be opened before adding oil to the reservoir.
This will allow the oil to fl ow more easily into the tank.
The vent should be fully closed during sustained periods of
inactivity or whenever the pump is stored. When closing the vent,
tighten the vent screw snug tight, so that the underside of the
screw head only slightly compresses the O-ring seat.
Figure 8 - Vent Screw
Vent Screw
5.8 Air On-Off Control
The pump air on-off control operates as follows:
ON position:
• Air from the plant air supply is directed to the pump pneumatic
circuit, activating the pump element. Hydraulic pressure will
start building immediately, and will be indicated on the pump
hydraulic pressure gauge.
• Pump will stop automatically when the user-adjustable pressure
setting is reached. Refer to Section 6.1 for additional details.
NOTICE
The user-adjustable pressure setting must be adjusted
before the pump is placed into operation. Refer to directions in
Section 5.9.
OFF position:
• Air from the plant air supply to the pump pneumatic circuit is
blocked (shut-off ).
• Some residual air pressure may still be present in the pump
pneumatic circuit.
WARNING
Air downstream of the air on-off control is NOT vented when
the OFF position is selected. Residual air pressure may be
present downstream of the control. Movement of hydraulic
actuators could occur when control valves are shifted, even
when the air on-off control is in the OFF position.
To prevent possible injury, stay clear of hydraulic actuators
until all pressure is completely relieved. With the air on-off
control in the OFF position, shift the control valve(s) through
all positions several times to relieve any residual pressure.
Figure 9 - Air On-Off Control
5.9 Air Pressure Adjustment
Adjustment of the pump air pressure setting results in a
corresponding change to the pump hydraulic pressure setting.
Adjust the pressure setting as described in the following steps:
1.
Move the air on-off control to the OFF position.
2.
Connect the air supply hose to the pump air inlet connection.
3.
Pull up the air pressure adjustment knob. See Figure 10.
4.
Turn the air pressure adjustment knob slowly counterclockwise
until the pump air pressure gauge indicates about 43.5 psi [3
bar].
5. While watching the pump air pressure gauge, slowly rotate
the air pressure adjustment knob clockwise until the gauge
indicates the air pressure setting that corresponds with the
hydraulic pressure setting required for your application.
NOTICE
The hydraulic-to-air pressure ratio varies, depending
on pump model. Refer to the ratios listed in the table in Section
4.1 and to the pressure-fl ow graphs in Section 4.5.
6. To prevent unexpected actuator operation from occurring in
the next step, be sure that all control valves are in the neutral
position.
Figure 10 - Air Pressure Adjustment Knob
and Pressure Gauge
LOCKED
Air Pressure Gauge
ADJUSTMENT
KNOB
UNLOCKED
7.
Move the pump air on-off control to the ON position.
8. Check the pump hydraulic pressure gauge. If necessary,
readjust the air pressure up or down as required, until the
corresponding hydraulic pressure setting is correct for your
application.
