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— The PRE3 is a pilot operated pressure control valve with

electric proportional control and mounting interface in

compliance with ISO 4401 standards.

— It is suitable to modulate the pressure in hydraulic circuits.

— The valve can be controlled directly by a current control

supply unit or by an electronic control unit to exploit valve

performance to the full (see at paragraph 9).

— The design of this valve has a mechanical

pressure limitation feature for higher safety of the

application.

— Five pressure control ranges up to 350 bar are

available.

0.750.75

31.7531.75

25.925.9

15.515.5

5.15.1

12.712.7

3131

M5M5

ø4ø 4

ø 7.5 (max)ø 7.5 (max)

21.521.5

30.230.2

40.540.5

3333

PRE3

PILOT OPERATED PRESSURE

CONTROL VALVE WITH ELECTRIC

PROPORTIONAL CONTROL

SERIES 20

MOUNTING INTERFACE OPERATING PRINCIPLE

SO 4401-03-02-0-05

(CETOP 4.2-4-03-350)

81 241/118 ED

SUBPLATE MOUNTING

ISO 4401-03

p max

350 bar

Q max 40 l/min

Maximum operating pressure:

- P port

- T port

bar 350

Minimum controlled pressure see p min = f(Q) diagram

Minimum flow

Maximum flow (see graph p max= f(Q))

l/min

Step response see paragraph 6

Hysteresis (with PWM 200 Hz) % of p nom < 5%

Repeatability % of p nom < ±1,5%

Electrical characteristic see paragraph 5

Ambient temperature range °C -20 / +60

Fluid temperature range °C -20 / +80

Fluid viscosity range cSt 10 ÷ 400

Fluid contamination degree

According to ISO 4406:1999

class 18/16/13

Recommended viscosity cSt 25

Mass kg 3,5

PERFORMANCES

(obtained with mineral oil with viscosity of 36 cSt at 50°C and electronic

control card)

HYDRAULIC SYMBOL

simplified detailed

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PRE3

SERIES 20

- IDENTIFICATION CODE

2 - CHARACTERISTIC CURVES

(measured with viscosity of 36 cSt at 50°C)

Typical control curves according to the current supplied to the solenoid (D24 version with maximum current 860 mA) for the available pressure

control ranges, measured with input flow rate Q = 10 l/min. Curves have been obtained without any hysteresis and linearity compensation and

they have been measured without any backpressure in T.

The full scale pressure is set in factory with a flow rate of 10 l/min. In case of higher flow rate, the full scale pressure will increase (see diagram

pmax = f (Q)).

PRESSURE CONTROL p = f (I)

MINIMUM CONTROLLED PRESSURE pmin = f (Q) PRESSURE VARIATION pmax = f (Q)

Q = 10 l/min factory setting

Seals:

N = NBR seals for mineral oil (standard)

V = FPM seals for special fluids

Series No.

(the overall and mounting dimensions remain unchanged

from 20 to 29)

Electrical proportional control

Size ISO 4401-03

Pressure control range

025 = 4 - 25 bar

070 = 4 - 70 bar

140 = 4 - 140 bar

210 = 5 - 210 bar

350 = 5 - 350 bar

D12 = Nominal solenoid voltage 12V DC

D24 = Nominal solenoid voltage 24V DC

Coil electrical connection:

for connector type EN 175301-803

(ex DIN 43650) (standard)

Pressure control

valve, pilot operated

RP E 3

-/ 20 K1

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PRE3

SERIES 20

5 - ELECTRICAL CHARACTERISTICS

Proportional solenoid

The proportional solenoid comprises two parts: tube and coil.

The tube, screwed to the valve body, contains the armature which

is designed to maintain friction to a minimum thereby reducing

hysteresis.

The coil is mounted on the tube secured by means of a lock nut and

can be rotated through 360° depending on installation clearances.

6 - STEP RESPONSE

(obtained with mineral oil with viscosity of 36 cSt at 50°C and electronic

control card)

Step response is the time taken for the valve to reach 90% of the

set pressure value following a step change of reference signal.

The table illustrates typical step response times measured with a

PRE3-210 and with input flow rate Q = 10 l/min, and a pressure oil

volume of 1 litre. The response time is affected by both the flow rate

and the oil volume inside the piping.

7 - INSTALLATION

We recommend to install the PRE3 valve either in horizontal

position, or vertical position with the solenoid downward. If the valve

is installed in vertical position and with the solenoid upward, you

must consider possible variations of the minimum controlled

pressure, if compared to what is indicated in paragraph 2.

Ensure that there is no air in the hydraulic circuit. In particular

applications, it can be necessary to vent the air entrapped in the

solenoid tube, by using the apposite drain screw in the solenoid

tube. Ensure that the solenoid tube is always filled with oil. At the

end of the operation, make sure of having screwed the drain screw

correctly.

Connect the valve T port directly to the tank. Add any backpressure

value detected in the T line to the controlled pressure value.

Maximum admissible backpressure in the T line, under

operational conditions, is 2 bar.

Valves are fixed by means of screws or tie rods on a flat surface

with planarity and roughness equal to or better than those indicated

in the relative symbols. If minimum values are not observed, fluid

can easily leak between the valve and support surface.

4 - HYDRAULIC FLUIDS

Use mineral oil-based hydraulic fluids HL or HM type, according to ISO 6743-4. For these fluids, use NBR seals (code N). For fluids HFDR type

(phosphate esters) use FPM seals (code V). For the use of other fluid types such as HFA, HFB, HFC, please consult our technical department.

Using fluids at temperatures higher than 80 °C causes a faster degradation of the fluid and of the seals characteristics. The fluid must be

preserved in its physical and chemical characteristics.

Surface finishing

NOMINAL VOLTAGE

V DC

12 24

RESISTANCE (at 20°C)

Ω 3.66 17.6

MAXIMUM CURRENT

A 1.88 0.86

DUTY CYCLE

100%

ELECTROMAGNETIC

COMPATIBILITY (EMC)

According to

2014/30/EU

PROTECTION FROM

ATMOSPHERIC AGENTS

(IEC 60529)

IP65

CLASS OF PROTECTION

Coil insulation (VDE 0580)

Impregnation

class H

class F

REFERENCE

SIGNAL STEP

0 → 100% 100 → 0%

Step response [ms] 80 40

PRE3-025 PRE3-070 PRE3-140 PRE3-210 PRE3-350

pressure value at 800 mA bar 28 82 145 215 335

max pressure value when I > I

bar 30 86 155 230 350

- MAX PRESSURE VALUES

This valve incorporates a mechanical limit of the maximum pressure, that operates independently of the applied current. This kind of design

ensures the pressure cannot rise over even if the solenoid current exceeds the maximum current (I > I

Values obtained with oil viscosity of 36 cSt at 50°C, Q = 10 l/min

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PRE3

SERIES 20

REPRODUCTION IS FORBIDDEN. THE COMPANY RESERVES THE RIGHT TO APPLY ANY MODIFICATIONS.

- OVERALL AND MOUNTING DIMENSIONS

10 - SUBPLATES

(see catalogue 51 000)

dimensions in mm

NOTE: at the first start up, or after a long period of

no use, it is necessary to vent the air through the

breather (3) placed at the end of the solenoid tube.

9 - ELECTRONIC CONTROL UNITS

EDC-112 for solenoid 24V DC

plug version

see catalogue

89 120

EDC-142 for solenoid 12V DC

EDM-M112 for solenoid 24V DC

DIN EN 50022

rail mounting

see catalogue

89 251

EDM-M142 for solenoid 12V DC

Mounting surface with sealing rings:

4 OR type 2037 (9.25x1.78) - 90 shore

Coil removal space

Breather (male hexagonal spanner 4)

EN 175301-803 (ex DIN 43650) connector

(included in the delivery)

Connector removal space

PMMD-AI3G with ports on rear

PMMD-AL3G with side ports

Ports dimensions P, T, A and B: 3/8” BSP thread

Fastening bolts: 4 SHC screws M5x70 - ISO 4762

Torque: 5 Nm (A8.8)

Threads of mounting holes: M5x10