ELECTRO-PROPORTIONAL VALVES--PRESSURE CONTROLS
EHPR98-T38B Proportional Reducing/Relieving
ISO SYMBOL
2.973.3
PERFORMANCE
DESCRIPTION
A direct-acting, spool-type, proportional, drop-in-style, flange-mounted, pressure
reducing/relieving valve, which can be infinitely adjusted across a prescribed range
using a variable electric input. Pressure output is proportional to DC current input.
The E-coil is an integral part of the valve assembly, and cannot be replaced or field-
serviced.
OPERATION
The EHPR98-T38B allows free flow from 1 to 3 when no current is applied to the coil.
When the coil is energized, 2 is connected to 1. Increasing current applied to the coil
will increase the control (reduced) pressure proportionally. If pressure at 1 exceeds
the setting induced by the coil, pressure from 1 is relieved to 2.
Note: Operation of manual override option: Rotate manual override screw clockwise
until desired regulated pressure is achieved.
FEATURES
• Economical drop-in style. • 1000-hour salt spray protection.
• Integral waterproof coil standard. • Optional 142 micron screen at inlet.
RATINGS
Maximum Inlet Pressure: 241 bar (3500 psi) at Port 2; 57 bar (820 psi) at Port 1;
34 bar (500 psi) at Port 3.
Flow Rating: 18.9 lpm (5.0 gpm)
Maximum Internal Leakage: Energized: 393 ml/min. (24 cu. in./min.) at 241 bar
(3500 psi); De-energized: 100 ml/min. (6 cu. in./min.) at 241 bar (3500 psi)
Cycle Life: One million cycles.
Oil Operating Fluid Temperature: -40° to 149°C (-40° to 300°F)
Storage Temperature: -40° to 70°C (-40° to 160°F)
Ambient Temperature: -40° to 80°C (-40° to 176°F)
Maximum Control Current: 1.38 amps for 10 VDC coil; 1.30 amps for 12 VDC coil;
0.69 amps for 20 VDC coil; 0.65 amps for 24 VDC coil
Control Pressure at Maximum Control Current: 56.6 bar (820 psi)
Hysteresis: at 100 Hz PWM: 4% of maximum control pressure
Resistance: 4.3 ohm (10V); 5.2 ohm (12V); 17.5 ohm (20V); 20.9 ohm (24V)
Valve Inductance: 80 mH (12V)
Environmental Rating: IP69K
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
Cavity: VC-T011; See page 9.111.1
Cavity Tool: CT-T011R0-x-G; See page 8.600.1
Seal Kits: SK-T011-N; SK-T011-V; See page 8.650.1
HYDRAFORCE
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®
FLOW lpm/gpm
PRESSURE bar/psi
Pressure Drop vs. Flow
Cartridge Only
1 to 3 ———; 2 to 1 - - - - -
3.4/50
6.9/100
10.3/150
13.8/200
17.2/250
3.8
1.0
7.6
2.0
11.4
3.0
15.1
4.0
18.9
5.0
Relieving Pressure 1 to 3
Typical Relieving/Reducing Pressure vs. Flow Characteristic
Typical Relieving Pressure at Various %s of Maximum Control Current
Inlet: 69 bar/1000 psi ——; Inlet 241 bar/3500 psi – – –
(Curves overlap on Relieving Pressure side of graph); 150 Hz PWM (Both Directions)
FLOW lpm/gpm
15.1
4.0
15.1
4.0
18.9
5.0
18.9
5.0
11.4
3.0
11.4
3.0
7.6
2.0
7.6
2.0
3.8
1.0
3.8
1.0
0
Reducing Pressure 2 to 1
30% Max. Control Current
0% Max. Control Current
% of MAXIMUM RELIEF PRESSURE
% of MAXIMUM REDUCING PRESSURE
50
0
25
75
100
125
150
50
25
75
100
125
150
0
45% Max. Control Current
175
60% Max. Control Current
75% Max. Control Current
100% Max. Control Current
CURRENT amps
PRESSURE bar/psi
Reducing Pressure vs. Current
6.9/100
13.8/200
20.7/300
27.6/400
62.1/900
0.2 0.4 0.6 1.00.8 1.41.2
Reducing Pressure 2 to 1
Inlet: 34.5 bar/500 psi; 150 Hz PWM; 12V Coil
34.5/500
41.4/600
48.3/700
55.2/800
Blue rectangles are links to other catalog pages.
PERFORMANCE
EHPR98-T38B
2.973.4
(continued)
DIMENSIONS
Drop-In-Style
Valve
MATERIALS
Cartridge including Coil: Weight:
0.32 kg. (0.70 lbs.) Steel with
hardened work surfaces. Zinc-
Nickel plated exposed surfaces.
HNBR O-rings standard. Coil is
encapsulated, high-temperature
magnet wire with zinc-nickel
plated shell.
Ported Body: Consult Factory
Mounting Screws: Must be ordered
separately: Part No. 4001015
EHPR98-T38B __ - __ - __ __ - __ - __ __ __ __ __
TO ORDER
Voltage
10 10 VDC
12 12 VDC
20 20 VDC
24 24 VDC
Termination
ER Deutsch DT04-2P
EJ Amp Junior Timer
Seals
N Hydrogenated Nitrile (HNBR)
V Fluorocarbon
®
HYDRAFORCE
HYDRAFORCE
.com
®
Option
None (Blank)
Manual Override M
Recommended Electronic Controllers:
See page 2.001.1 or our Electronics catalog.
1.29
32.7
2.14
54.3
0.36
9.1
1.66
42.1
Mounting
Screw
Torque:
0.9–1.1 ft-lbs
(1.2–1.5 Nm)
Manual
Override
Option
0.72
18.2
1.43
36.3
0.86
21.9
2.13
54.1
Aluminum
Body
Shown
2.50
63.5
INCH
MILLIMETRE
1.30
33.0
1.42
36.0
5°
2.00
50.8
2.12
53.8
TYP
2.62
66.5
1.17
29.8
0.61
15.5
0.28
7.1
0.25
6.4
Screen
Option
Note: To operate
manual override, rotate
screw clockwise until
desired pressure is
achieved.
0
6.9/100
13.8/200
20.7/300
27.6/400
34.5/500
PRESSURE (bar/psi)
TIME seconds
2.252.001.751.501.250.75 1.000.500.2502.50
Typical Step Response Curve
Inlet 241bar/3500 psi; DC Current; Regulated Port Blocked
Pressure
Current (amps x 100)
41.4/600
48.3/700
55.2/800
62.1/900
Diode
(Blank) None
Z Zener Diode,
Bidirectional
Other voltages are available.
Consult factory.
Screen Option
None (Blank)
142 micron inlet port S
FREQUENCY Hz
Typical Frequency Response Curves
Inlet: 69 bar/1000 psi; DC Current; Regulated Port Blocked
(For 241 bar/3500 psi inlet frequency response curves, consult factory.)
Signals: 40% ± 10% ———; 50% ± 25% — — —
70% ± 20% - - - - - -; 80% ± 10% — - — - —
01050
180
90
45
0
135
PHASE ANGLE degrees
8
10
4
6
12
2
-4
-2
0
-6
-8
-10
-12
MAGNITUDE dB
Porting
Cartridge Only 0
SAE 6 6T
SAE 8 8T
1/4 in. BSP* 2B
3/8 in. BSP* 3B
*BSP Body; U.K. Mfr. Only
Blue rectangles are links to other catalog pages.
