Main Spool - Danfoss PVG 100 Service Manual

Service Manual
PVG 100 Component Troubleshooting
Failure mode
Valve sections will not build pressure
Normally it will be one section, but not all
sections

Main Spool

Failure mode
Section will not build pressure in one spool
direction
Main valve spool stuck in valve body (if being
used with electrical actuator)
Mechanical actuator main valve spool stuck in
valve body
Main spool stuck in valve body
Section will not stroke off
PVG 100 Proportional Valves
Cause
Worn shuttle disc
Excessive air entrained in the hydraulic oil
Shuttle disk accidentally pushed in
Serviceability: Not serviceable. Ensure entire system is clean.
Shuttle valve
Exploded view shows internal parts.
Do not disassemble valve.
Description: Main directional control.
Location: PVB (valve section) module.
Function: Controls oil flow from pump to work ports A or B.
Cause
Load sense passages in spool are blocked
Refer to Pressure reducing valve
Hard particle binding spool in bore
Tie rod over torqued
Valve stack mounting surface is not flat causing a
bind on the valve stack
Load sense drain holes are plugged
11048807 • Rev BA • October 2014
Corrective action
Replace complete module (seat is pressed into
module)
Ensure that the oil has enough dwell time in tank,
has good anti-foaming agent, and pump inlet
vacuum is within specifications
Check disk spacing - replace module
Ball should move
freely behind disk
P107 841
Corrective action
Flush out load sense passages in the spool. Spool
will need to be removed to clean
Replace PVM and PVE. Be sure that pilot valve is
assembled correctly.
Look down into the A and B work ports to see if
the particle can be removed while the spool is in
the valve body. Replace valve section.
Valve body and spool will need to be replaced
per valve specifications
Replace tie rod kit which includes section seals
and torque to 28 Nm [248 lbf•in]
Ensure the mounting surface is flat*
Flush out load sense passages in the spool. Spool
will need to be removed to clean
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