EHPR08-33 Proportional Reducing/Relieving Valve
USASI/ISO:
SYMBOLS
2.970.1
PERFORMANCE
Relief Pressure vs.
Current (DC) Characteristic
Reducing Pressure ➁ to ➀
PRESSURE (psi)
0
50
100
150
200
250
300
350
400
PRESSURE (bar)
0
5
10
15
20
25
30
% of Maximum Control Current
02010 30 50 70 9040 60 80 100
FLOW (gpm)
FLOW (lpm)
PRESSURE (bar)
PRESSURE (psi)
Pressure Drop vs. Flow Characteristic
For Flow ➀ to ➂ with Coil De-energized
0 0.2 0.4 0.6 0.8 1.0
0
00
25
150
100
125
50
75
2
4
6
8
10
1.0 3.02.0 4.0
Cartridge
Only
DESCRIPTION
A screw-in, cartridge-style, direct acting, spool-type reducing/relieving valve, which
can be infi nitely adjusted across a prescribed range using a variable electric input.
Pressure output is proportional to DC current input. This valve is intended for use as
a pressure control device in demanding applications.
OPERATION
The EHPR08-33 allows free fl ow from ➀ to ➂ when no current is applied to the coil.
When the coil is energized,
➁ is connected to ➀. Increasing current applied to the coil
will increase the control (reduced) pressure proportionally. If pressure at
➀ exceeds
the setting induced by the coil, pressure from
➀ is relieved to ➂.
Note: Back pressure on port
➂ becomes additive to the pressure setting at a 1:1 ratio.
FEATURES
• 12 and 24 volt coils standard.
• Optional manual override.
• Industry common cavity.
• Optional waterproof E-coils rated up to IP69K.
RATINGS
Maximum Inlet Pressure at port ➁: 207 bar (3000 psi)
Maximum Tank Pressure at port
➂: 34.5 bar (500 psi)
Maximum Control Current: 1.2 amps for 12 VDC coil; 0.6 amps for 24 VDC coil;
For other voltages, consult factory
Dither Frequency Required: 200 Hz
Typical Frequency Response: See Section 10
Hysteresis: Less than 3%
Reducing/Relieving Pressure Range from Zero to Maximum Control Current:
0–26 bar (0–375 psi)
Rated Flow: 4.0 lpm (1.05 gpm), ΔP=6 bar (87 psi), Cartridge only,
➀ to ➂ coil de-energized
Step Response: T
ON <30 ms; TOFF <12 ms
Flow Path: Free Flow:
➀ to ➂ coil de-energized; Reduced: ➁ to ➀ coil energized;
Relieving:
➀ to ➂ coil energized
Temperature: -40 to 120°C (-40 to 250°F), with standard Buna N seals
Ambient Air Temperature: -40 to 80°C (-40 to 176°F)
Filtration: See page 9.010.1
Fluids: Mineral-based or synthetics with lubricating properties at viscosities of
7.4 to 420 cSt (50 to 2000 sus); See Temperature and Oil Viscosity, page 9.060.1
Installation: No restrictions; See page 9.020.1
Cavity: VC08-3; See page 9.108.1; Cavity Tool: CT08-3XX; See page 8.600.1
Seal Kit: SK08-3X-00; See page 8.650.1
ELECTRO-PROPORTIONAL VALVES—PRESSURE CONTROLS
Typical Relieving/Reducing Pressure vs. Flow Characteristic
Typical Relieving Pressure at Various %’s of Maximum Control Current
Pressure Range “A” (26 bar/375 psi); Cartridge in Body
FLOW (gpm)
% of MAXIMUM REDUCING PRESSURE
50
0
25
75
100
125
% of MAXIMUM RELIEF PRESSURE
50
0
25
75
100
125
FLOW (lpm)
4.0 3.0 2.0 1.0 0 1.0 2.0 3.0 4.0
0 0.20.2 0.40.4 0.60.6 0.80.8 1.01.0
Reducing Pressure ➁ to ➀Relieving Pressure ➀ to ➂
100% Max. Control Current
85% Max. Control Current
65% Max. Control Current
50% Max. Control Current
HYDRAFORCE
.com
®
Blue rectangles are links to other catalog pages.
D-Coil Terminations
DS Dual Spades
DG DIN 43650
DL Leadwires (2)
DL/W Leads w/Weatherpak
®
Connectors
E-Coil Terminations
ER Deutsch DT04-2P (IP69K Rated)
EY Metri-Pak
®
150 (IP69K Rated)
PERFORMANCE
EHPR08-33
2.970.2
MATERIALS
Cartridge: Weight: 0.25 kg. (0.55 lbs.)
Steel with hardened work surfaces.
Zinc-plated exposed surfaces.
Buna N O-rings standard.
Standard Ported Body: Weight:
0.16 kg. (0.35 lbs.) Anodized high-
strength 6061 T6 aluminum alloy,
rated to 207 bar (3000 psi). Ductile
iron bodies available; dimensions
may differ. See page 8.008.1
EHPR Series Coil:
D-Coil: Weight: 0.11 kg. (0.25 lbs.)
Unitized, thermoplastic encapsu-
lated, Class H high temperature
magnetwire. See page 3.200.1
E-Coil: Weight: 0.14 kg. (0.3 lbs.)
Fully encapsulated with rugged
external metal shell. Rated up to
IP69K with integral connectors.
See page 3.400.1
TO ORDER
EHPR08-33__- __ - __ - __ __ __ __
Porting
Cartridge Only 0
SAE 6 6T
SAE 8 8T
3/8 in. BSP* 3B
1/2 in. BSP* 4B
*BSP Body;
U.K. Mfr. Only
Seals
Buna N (Std.) N
Fluorocarbon V
Voltage
0 Less Coil
10 10 VDC* (1.5 amps max.)
12 12 VDC (1.2 amps max.)
20 20 VDC* (0.75 amps max.)
24 24 VDC (0.6 amps max.)
*For use where there is a voltage drop across the controller.
2.06
52.3
0.16
4.1
Manual Override Option
0.13 (3.3) Hex Socket
(continued)
Coils with internal diode are available. Consult factory.
DIMENSIONS
24 6
FREQUENCY (Hz)
Typical Frequency Response Curves
Input Current and Regulated Pressure
810 20 30 405060
Signal 25% ±10%
Signal 50% ±50%
Signal 85% ±10%
Inlet: 35 bar (500 psi),
4 lpm (1 gpm)
Regulated: Blocked
Tank: <0.15 bar (2 psi)
Input Signal: Sinusoidal
-180
-90
-45
0
-135
PHASE (degrees)
9
12
6
3
0
-3
-6
-9
GAIN (dB)
Current
0
500
1000
1500
CURRENT (mA)
0
3.4
50
6.9
100
10.3
150
13.8
200
17.2
250
20.7
300
24.2
350
27.6
400
REGULATED PRESSURE (bar/psi)
TIME (msec.)
1006050403020100203040
Typical Step Response Curve
Pressure
Option
None
(Blank)
Manual Override M
®
HYDRAFORCE
HYDRAFORCE
.com
®
(Consult factory for other voltages.)
Recommended Electronic Controllers:
See page 2.001.1 or our Electronics catalog.
When using
EHPR08-33
with an E-Coil,
remove
waterproof
O-ring seals
from the
actuator tube
before
installing
the coil.
Blue rectangles are links to other catalog pages.
