Pvg 32 Component Troubleshooting; Pressure Relief Valve; Pressure Reducing Pilot Valve - Danfoss PVG 32 Service Manual

Service Manual
PVG 32 Proportional Valve Group

PVG 32 Component Troubleshooting

Pressure relief valve

Failure mode
Will not build pressure
External leaking
Pressure setting is wrong
Instability when PC and inlet relief
has too low of a delta between
them

Pressure reducing pilot valve

Failure mode
Main spools are slow, driven by
PVE 13 Bar [190 PSI] pilot system
Main spools will not move
mechanically or electrical
PVHC 25 bar [360 psi] pilot system
- main spools are slow
20 | © Danfoss | February 2017
Description: Adjustable relief valve. Adjustment range 50 Bar [700 PSI] to 350 Bar [5000 PSI].
Location: The relief is in all PVP Inlet modules
Function: Provides maximum pressure setting above pump pressure setting 30 Bar [450 PSI] Delta for
open center and closed inlet sections
Cause
Contamination
Damaged seat and poppet
Pressure adjustment backs off (on open
center application)
PC at pump should be set 20 bar below relief
valve
Serviceability: Non serviceable.
Valve removal tool P/N: 155L6485. Torque to 20 Nm [180 lbf•in].
Description: Pressure reducing valve at fixed pressure.
Location: The pressure reducing valve is a option in some PVP Inlet modules.
Function: Provides 10-15 bar [145-218 psi] internal pressure for electrical (PVE) actuators or provide 25
Bar (360 PSI) (PVHC) and supply for external remote hydraulic actuators (HRC). These pressures are only
present when the load pressures are high enough to satisfy the required regulated pressure. The open
center system at low pump flow may only develop 9 Bar (130 PSI)
Cause
Contamination
Pump pressure too low - below 9 Bar [130 PSI] Closed center: System increase stand-by to 13 Bar [190 PSI]
High tank port pressure. Do not exceed 40 Bar
[580 PSI] tank pressure (For PVPs without T0
option)
2
Oil viscosity 460 mm /S [2128 SUS] too high
(cold oil or incorrect viscosity oil)
For T0 option only not being connected to
tank or restricted to tank
Internal pressure reducing valve parts
misassembled
Contamination
Pump pressure too low - below 20 Bar [290
PSI]
High tank port pressure. Tank pressure should
not exceed 40 Bar [580 PSI] (For PVPs without
T0 option)
2
Oil viscosity - 460 mm /S [2128 SUS] too high
(cold oil or incorrect viscosity oil)
Corrective action
While under pressure, back out to minimum pressure and allow oil
to leak by for approx. 5 seconds and then readjust to correct
pressure - Replace valve
Replace complete assembly
Adjust to model code specification
Adjust to model code specification
Corrective action
Disassemble and clean
Open center: Check gear per pump manufacture procedure
Check system for other components before valve inlet that may
provide a path tank
Clear restrictions in return system.
Warm up system or replace oil with correct viscosity
Connect T0 (PVP) port option to tank or remove restriction
Reassemble the internal pressure reducing valve parts correctly
Disassemble and clean
Closed center: System increase stand-by to 20 Bar [290 PSI]
Open center: Check gear per pump manufacturers procedure
Check system for other components before valve inlet that may
provide a path tank
Check for restrictions in return system and remove
Warm up system or replace oil with correct viscosity
11039167 | AX00000031en-US0301