7-19
Catalogue HY11-3500/UK
Direct Operated Pressure Reducing Valve
Series PRDM
7
PRDM_UK.INDD RH_12.04.10
Parker Hannifin GmbH
Hydraulic Controls Division
Kaarst, Germany
Characteristics
Series PRDM are direct operated pressure reducing valves to
regulate pressure in one area of a hydraulic circuit at a prede-
termined level below normal system pressure. Additionally, an
integral pressure relieving function for the secondary reduced
pressure circuit is incorporated into the design.
Funtion
These valves are "normally open" devices that allow fluid to
flow trough the controlled port during their non-actuated or "at
rest" condition. When downstream pressure exceeds the value
set by the spring force, the control piston moves off its seat,
closing off the flow path and thus reducing the fluid passing
through from the main system. The cushioned piston modulates
to maintain the preset pressure in this branch of the hydraulic
circuit. If, due to external forces, the pressure continues to rise
in this branch circuit, the piston will keep moving against the
spring force allowing fluid to be drained to the tank, thereby
limiting maximum pressure to the valve's setting.
Features
• 3-waydesignforpressurerelievingofthesecondary
side
• Thedirectoperated,cushionedpistondesignresultsin
fast response, low leakage and minimal hysteresis.
• Reducedpressureinthe'P','A'or'B'port.
• Pressuresettings
bar 25, 70, 160, 210, 350 for PRDM2,
bar 19, 50, 100, 150, 210 for PRDM3.
• Gaugeport...
• PRDM2-NG06(CETOP3)
PRDM3-NG10(CETOP5)
Max. leakage P - A: 15ml/min
ExamplePP
Technical data
Schematics
PRDM*AA
PRDM*BB
PRDM*PP
Gauge port option C
Series PRDM2 PRDM3
Port size
06 10
Mounting pattern ISO 4401
Max. operating pressure
P,A,B [bar] 350 315
T [bar] 50 50
Weight [kg] 1.3 2.6
MTTF
D
value [years] 150
Ambient temperature [°C] -20...+50
Fluid Hydraulic oil acc. to DIN 51524...525
Fluid temperature [°C] -20...+80
Viscosity range [cSt][mm²/s] 12...230
Filtration ISO4406(1999)18/16/13
7-20
PRDM_UK.INDD RH_12.04.10
Catalogue HY11-3500/UK
Direct Operated Pressure Reducing Valve
Series PRDM
7
Parker Hannifin GmbH
Hydraulic Controls Division
Kaarst, Germany
Code Connection
PP P
AA A
BB B
Code Adjustment
S
Slotted head
screw with
lock nut
L Key lock
K Turning knob
2)
Size Pressure
range
AdjustmentPressure
reducing
valve, direct
operated
Seal
FPM
PRD
V
Code Size
2 NG06
3 NG10
Manapak
M
Pressure range
1)
Code PRDM2 Code PRDM3
02 up to 25 bar
01 up to 19 bar
06 up to 64 bar 05 up to 50 bar
16 up to 160 bar
10 up to 100 bar
21 up to 210 bar 15 up to 150 bar
35 up to 350 bar
21 up to 210 bar
Design
series
Ordering Code
Port
reduction
Code Gauge port
G G¼
C Coupling M16
Gauge
port
2)
NG06 only
1)
For optimum performance it is recommended to
use the appropriate pressure stage, e.g. for 150
bar reduced pressure use code 16 - 160 bar.
7-21
Catalogue HY11-3500/UK
Direct Operated Pressure Reducing Valve
Series PRDM
7
PRDM_UK.INDD RH_12.04.10
Parker Hannifin GmbH
Hydraulic Controls Division
Kaarst, Germany
Performance Curves
PRDM2 02
PRDM2 16/21
PRDM2 06
PRDM2 35
All characteristic curves measured with HLP46 at 50°C.
7-22
PRDM_UK.INDD RH_12.04.10
Catalogue HY11-3500/UK
Direct Operated Pressure Reducing Valve
Series PRDM
7
Parker Hannifin GmbH
Hydraulic Controls Division
Kaarst, Germany
Performance Curves
PRDM3 05
PRDM3 15
PRDM3 10
PRDM3 21
0
10
20 30 40 50 60 70 80
0
30
60
90
120
150
180
210
240
P min
e
Setting pressure pe [bar]
Flow rate Q [l/min] (P P’)
10
203040
(T P’)
PRDM3 01
All characteristic curves measured with HLP46 at 50°C.
7-23
Catalogue HY11-3500/UK
Direct Operated Pressure Reducing Valve
Series PRDM
7
PRDM_UK.INDD RH_12.04.10
Parker Hannifin GmbH
Hydraulic Controls Division
Kaarst, Germany
Dimensions
PRDM2
PRDM3
Seal kit order code
Seal PRDM2 PRDM3
V SK-PRDM2-V SK-PRDM3-V
7-24
PRDM_UK.INDD RH_12.04.10
Catalogue HY11-3500/UK
7
Parker Hannifin GmbH
Hydraulic Controls Division
Kaarst, Germany
Notes