Enerpac VM43-LPS Instrucciones De Mantenimiento página 11

c. Turn the relief valve set screw counter-clockwise one
turn.
d. Rotate the control valve handle to the advance/stressing
("1") position.
e. SLOWLY turn the relief valve set screw clockwise until
"A" port pressure increases to the desired setting.
NOTE: To ensure proper operation of the retract-side
pressure limiting valve, the relief valve setting must be
at least 7,000 psi [482 bar].
9. When the desired pressure setting is reached, lock the set
screw with the locknut. DO NOT overtighten.
10. Move the control valve handle to the neutral/hold ("3")
position and check for pressure drift.
NOTE: For the fi rst 30 seconds, the pressure may drift down
5% from the initial pressure and then must stabilize.
For example: at a 10,000 psi pressure setting, it is permissible
for the pressure to drift down 500 psi to a fi nal pressure value
of 9,500 psi after 30 seconds. For the next 10 seconds, an
additional pressure drop of 150 psi (maximum) is permitted.
B
"B" Port
Locknut
Figure 9, Adjustment Details, Relief Valve
2
3
1 = Advance
2 = Retract
3 = Neutral
Figure 10, Valve Handle Positions
11. After checking for drift, move the control valve handle back to
the advance/stressing ("1") position to recheck the pressure
setting.
12. Before turning off pump, rotate the control valve handle
momentarily to the retract ("2") position to relieve pressure
at the "A" port. Then, rotate the handle to the neutral/hold
("3") position. Check that "A" port gauge indicates zero (0)
psi.
13. Stop the pump.
Relief Valve Body
A
"A" Port
Set Screw
A
B
1
Setting the retract-side pressure limiting valve
Set the retract-side pressure limiting valve as described in the
following procedure. Refer to fi gures 10 and 11.
1. Set relief valve pressure as described in the previous section.
Relief pressure must be set fi rst, before setting the retract-
side pressure.
2. Install a 0-15,000 psi [0-1,035 bar] gauge in both the "A"
port and in the "B" port (if not previously installed).
3. To allow adjustment, loosen the set screw locknut on the
retract-side pressure limiting valve (See fi gure 11).
4. Be sure that the control valve handle is in the neutral/hold
("3") position (see fi gure 10 for valve positions).
5. Start the pump and allow the oil to warm.
6. Rotate the control valve handle to the retract/seating ("2")
position and allow system pressure to build. The "B" port
pressure gauge should indicate 6,500 psi +/- 500 psi [448
bar +/-34 bar].
7. If pressure adjustment is required: Using an Allen wrench,
slowly turn the limiting valve set screw clockwise to increase
pressure or counter-clockwise to decrease pressure.
NOTE: To obtain an accurate setting, decrease the pressure
to a point below the fi nal setting and then slowly increase the
pressure until it reaches the fi nal setting.
8. When the desired pressure is set, tighten the set screw
locknut to 5-6 ft-lbs [7-8 Nm]. DO NOT overtighten.
9. Rotate the control valve handle to the neutral/hold ("3")
position.
10. Before turning off pump, be sure that the "A" port gauge
indicates zero (0) PSI. If any pressure is indicated, move the
control valve handle to the retract/seating ("2") position and
back to the neutral/hold ("3") position.
11. Stop the pump.
Locknut
B
"B"
Port
Figure 11, Adjustment Details, Retract-Side
Pressure Limiting Valve
11
Set Screw
A
"A"
Port