Charge Pressure Relief Valve Adjustments
Operate the system with the pump in neutral (zero displacement), when measuring charge pressure.
This procedure explains how to check and adjust the charge pressure relief valve.
Charge Pressure Adjustment
Case drain port L4
Charge pressure gauge port M3
Adjustment
screw
5 mm
Locknut
13 mm
Case drain port L2
P104466
12 N•m
[9 lbf•ft]
Optional construction port M14
0 - 10 bar [0 - 100 psi]
9/16 (069/078) / 5/8 in (147/165/210/250)
70 N•m [52 lbf•ft] (078)
150 N•m [110 lbf•ft] (147/165/210/250)
0 - 10 bar [0 - 100 psi]
3/8 in (069/078) /
9/16 in (089/100/147/165)
5/8 in (210/250)
70 N•m [52 lbf•ft]
0 - 10 bar [0 - 100 psi]
3/16 in
0 - 50 bar [0 - 1000 psi]
1/4 in
12 N•m [9 lbf•ft]
24 N•m [18 lbf•ft]
1. Install a 50 bar [1000 psi] pressure gauge in charge pressure gauge port M3.
2. Install a 10 bar [100 psi] gauge at case drain port L2 or L4.
The table below shows the acceptable actual pump charge pressure range for some nominal CPRV
settings (refer to model code located on serial number plate).
Charge Pressure Range according to model code
Code
20
24
26
30
Actual charge
pressure, bar [psi]
20 ± 1.5
[290 ± 21.8]
24 ± 1.5
[348 ± 21.8]
26 ± 1.5
[377 ± 21.8]
30 ± 1.5
[435 ± 21.8]
The factory set pressures at 1800 min
-1
(rpm) pump speed and a reservoir temperature of 50°C
[120°F], and are referenced to case pressure. At higher pump speeds with higher charge flows the
charge pressure will rise over the rated setting. Depending on the pressure rating, the charge
pressure relief valve may have one or two springs.
3. Loosen the locknut and turn the adjusting screw clockwise to increase the setting, and
counterclockwise to decrease it.
The approximate adjustment per turn
Number of springs
Change per turn
1 Spring
consult factory
2 Springs
3.9 bar [56.6 psi]
4. Torque locknut to 12 N•m [9 lbf•ft], while holding the adjusting screw.
5. Remove the gauges and plug the ports, when the desired charge pressure setting is achieved.
Service Manual
H1P 045/053/060/068 Axial Piston Single Pumps
Adjustments
36 |
©
Danfoss | June 2020
AX152886481964en-000405