Main Spool - Danfoss PVG 32 Service Manual

Service Manual
PVG 32 Proportional Valve Group
PVG 32 Component Troubleshooting
Failure mode
Will not build pressure in A or B
work port

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
28 | © Danfoss | February 2017
Cause
Contamination preventing shuttle ball from
building load sense relief pressure
LS A, B shuttle
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
* Flatness in millimeters - T= 0.35 mm X number of PVB modules + 1
Serviceability: Main spool is serviceable depending on failure mode.
1. Remove manual actuator using a 5 mm internal hex wrench to remove the 4 mounting screws.
CAREFULLY place the main spool in to an appropriate fixture or vice with card board, rubber hose or
heavy shop towels on the jaws and tighten just enough to keep the spool from turning in the vice.
DO NOT over tighten the main spool in the vice as it will be distorted and or scratched on sealing
lands and the spool will need to be replaced.
2. Remove the tension rod end using a 13 mm open end wrench.
3. Remove the plug at the other end using an 11 mm, or if it has a detent option, use a 12 mm open end
wrench.
4. Flush out openings into the main spool cavity at each end.
Corrective action
Replace complete PVB module
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.
NOTE: 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*
11039167 | AX00000031en-US0301
Shuttle
ball
P107 821