TROUBLESHOOTING AND REPAIR FOR TORQUE WRENCH VALVES
In diagnosing malfunctioning valves, certain symptoms may be
common not only to valves, but often to hydraulic equipment in
general. Before repairing the valve, mount a VM32 valve (or a
similar manual valve) onto the pump and verify that the problem
is not with the pump.
WARNING: Disconnect power before beginning any
maintenance or repairs. Standard safety procedures are
to be followed during disassembly and reassembly to
minimize any possibility of injury.
TROUBLESHOOTING
1.
Inability to obtain any pressure may be the result of damaged
connector seals, or failed relief valve components (items
14, 29, 30, fi gures 3 and 4), or an indication that the valve
stack (item 1, fi gure 2) needs to be rebuilt. These problems
are usually a symptom of contaminated hydraulic oil. The
system should be drained and refi lled with fresh ENERPAC
hydraulic oil.
2.
Pressure
leaks
that
proportionately with increasing pressure ranges are usually
the result of leaking gaskets or threaded surfaces such as
NPTF
fi ttings or plugs.
3.
Ball seat leakage is often erratic and intermittent and is
caused by contaminants trapped on the sealing edge. Over
time, as wear occurs, valve stack (item 1, fi gure 2) will need
to be replaced.
4.
Leakage observed on the external surfaces is an indication
that O-rings (items 44, 45, fi gure 1; item 13, fi gure 2; item 49,
fi gure 3; item 17, fi gure 4) and back-up ring (item 18, fi gure
4) may need replacement.
CONTROL VALVE DISASSEMBLY
1.
Remove the four socket head cap screws (item 176, fi gure
1) securing the valve assembly to the pump. If installed,
remove pressure transducer to gain access to screws.
Remove valve assembly from pump.
2.
Remove the return tube and gasket (not shown).
3.
Remove the multi-port assembly (if equipped - items 50-56
and 61-62, fi gure 1).
4.
Remove capscrews (item 40, fi gure 1) and separate the
body (item 34, fi gure 1) from the manifold (item 33, fi gure
1). Remove O-rings (items 44, 45, fi gure 1) and inspect for
damage. Replace if necessary.
5.
On older versions without externally adjustable "B" side
relief valve, remove spring, ball cap and ball (items 36-38,
fi gure 1) from bottom of body (item 34, fi gure 1). Inspect all
parts and replace if necessary. Remove seat (item 35, fi gure
1) only if worn or damaged.
6.
On newer versions with externally adjustable "B" side relief
valve, remove acorn nut, copper gaskets and jam nut (items
70, 71, 76, fi gure 1) from the top of the body (item 34, fi gure
1). Remove set screw (item, 75, fi gure 1), spring, guide and
ball (items 36-38, fi gure 1). Inspect all parts and replace if
necessary. Remove seat (item 35, fi gure 1) only if worn or
damaged.
7.
Remove and inspect the poppet valves as described in the
"Poppet Valve Disassembly" section of this document.
8.
Remove and inspect the relief valve as described in the
"Relief Valve Disassembly" section of this document.
All manuals and user guides at all-guides.com
are
consistent
and
increase
POPPET VALVE DISASSEMBLY
Repeat the following steps for each poppet valve:
1.
Remove the four socket head cap screws (item 42, fi gure 1)
and remove the poppet valve assembly (item 41, fi gure 1).
2.
Inspect the three O-rings (item 13, fi gure 2) for damage
such as nicks, cuts or extrusion of material. Replace if
necessary.
3.
Remove set screw (item 9, fi gure 2) and valve plug (item 3,
fi gure 2).
4.
Electric valves only: Remove solenoid stem (item 6, fi gure 2).
Air actuated valves only: Disassemble and remove air
actuator assembly (items 18-20 and 22-28, fi gure 2).
5.
Disassemble and inspect valve stack (items 1A - 1H, fi gure 2).
6.
Inspect O-rings (item 1H, fi gure 2) and Glyd Rings (item
1E, fi gure 2) for damage such as nicks or cuts. Replace if
necessary.
Note: Poppet set (item 1G, fi gure 2) is a matched
subassembly. It is available only as a pre-assembled
component.
7.
Inspect the bore in the body (item 2, fi gure 2) for damage
such as scratches, nicks or wear. Replace if necessary.
RELIEF VALVE DISASSEMBLY
1.
Remove the six socket head cap screws (item 48, fi gure
1) and remove the relief valve assembly (item 47, fi gure 1)
from the control valve body (item 34, fi gure 1).
2.
Remove the knob (item 27, fi gure 4) from the relief valve
subassembly and remove the ball (item 24, fi gure 4).
3.
Remove the O-rings (item 49, fi gure 3) and inspect for
damage. Replace if necessary.
4.
Remove the relief valve subassembly (item 28, fi gure 3) from
the relief valve body (item 31, fi gure 3).
5.
Remove the seat (item 29, fi gure 3) from the body. Inspect
the seat for damage such as nicks or dents on the sharp
edge of the internal diameter. Replace if necessary.
6.
Remove the pipe plugs (item 32, fi gure 3) and clean the
body. Inspect body for damages and replace if necessary.
7.
Remove piston, guide, spacer, back-up ring, O-ring (items
14, 15, 19, 20, 21, fi gure 4) and inspect for damage. Replace
if necessary.
8.
Remove O-ring and back-up ring (items 17, 18, fi gure 4) and
inspect for damage. Replace if necessary.
9.
Remove cap (item 25, fi gure 4) from the body (item 16, fi gure 4).
10. Remove guides (item 22, fi gure 4) and spring (item 23, fi gure 4).
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