RE 

29564-XL 
Edition: 2020-11
Replaces: 2018-09
RA87651324_AA

Directional servo valve

with mechanical position feedback

Type 4WS2EM ...XL
▶▶ Size 6
▶▶ Component series 2X
▶▶ Maximum operating pressure 315 bar
▶▶ Maximum flow 48 l/min

ATEX units
For potentially explosive atmospheres
Information on explosion protection:
▶▶ Area of application in accordance with the
Explosion Protection Directive 2014/34/EU: II 3G
▶▶ Type of protection:
Ex ic IIC T4 Gc according to EN IEC 60079-0 /
EN 60079-11 and IEC 60079-0 / IEC 60079-11
H8123

Features Contents

▶▶ 4 or 3-way version Features1

▶▶ For intended use in potentially explosive atmosphere Ordering code 2
▶▶ Valve for position, force, pressure or velocity control Symbols3
▶▶ For subplate mounting Function, section, symbol 4
▶▶ Porting pattern according to ISO 4401-03-02-0-05 Technical data 5, 6
(however, without locating hole) Electrical connection 7
▶▶ Dry control motor, no contamination of the solenoid Characteristic curves 8 … 11
gaps by the hydraulic fluid Dimensions 12, 13
▶▶ Can also be used as 3-way version Flushing plate 13
▶▶ Wear-free control spool return element Accessories14
▶▶ Pressure chambers at the control sleeve with gap seal, Further information 14
therefore no wear of seal ring

Notice: The documentation version with which the

product was supplied is valid.

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Ordering code

01 02 03 04 05 06 07 08 09 10 11 12 13
4WS2EM 6 – 2X / B 11 XL ET K17 V

01 Directional servo valve, 4-way version, 2-stage, with mechanical feedback, for external control electronics, 4WS2EM
electrically operated

02 Size 6 6

03 Component series 20 … 29 (20 … 29: unchanged installation and connection dimensions) 2X

Nominal flow
04 2 l/min 2
5 l/min 5
10 l/min 10
15 l/min 15
20 l/min 20
25 l/min 25
Characteristic curves, see page 11 (observe tolerance field of the flow/signal function)

05 Control sleeve exchangeable B

06 Valve for external control electronics; coil no. 11 (30 mA/85 Ω per coil) 11

Explosion protection
07 "Type of protection ic" XL
For details, see information on explosion protection, page 6

08 Pilot oil supply and return internal ET

Inlet pressure range

09 10 … 210 bar 210
10 … 315 bar 315

Electrical connection
10 Without mating connector; connector K17

Control spool overlap (in % of the nominal stroke)

11 0 … 0.5% negative E
0 … 0.5% positive D
3 … 5% positive C

Seal material (observe compatibility of seals with hydraulic fluid used, see page 6)
12 FKM seals V

Special versions
13 Standard version no code
The channels P → B and A → T are open 10% of the nominal quantity without control (de-energized state). -100
The channels P → A and B → T are open 10% of the nominal quantity without control (de-energized state). -102

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Symbols

Control spool overlap "E" Control spool overlap "C" and "D"
A B A B

Standard
a, b a, b
P T P T

A B A B

Special version "-100"

P T P T

A B A B

Special version "-102"

P T P T

Notice:
Representation according to DIN ISO 1219-1.

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Function, section, symbol

Valves of type 4WS2EM ...XL are electrically operated, The control spool (3) is connected to the flapper plate or
2-stage directional servo valves. They are mainly used to the torque motor by means of a bending spring
control position, force, pressure or velocity. (mechanical feedback) (9). The position of the control
The valves are made of an electro-mechanical converter spool (3) is changed until the feedback torque across the
(torque motor) (1), a hydraulic amplifier (nozzle flapper bending spring and the electro-magnetic torque of the
plate system) (2) and a control spool (3) in a sleeve torque motor are balanced and the pressure differential at
(2nd stage) which is connected with the torque motor via the nozzle flapper plate system becomes zero.
a mechanical feedback. The stroke of the control spool (3) and consequently the
An electrical input signal at the coils (4) of the torque flow of the servo valve are controlled proportionally to the
motor generates a force by means of a permanent magnet electrical input signal. It must be noted that the flow
which acts on the armature (5), and in connection with depends on the valve pressure drop.
a torque tube (6) results in a torque. This causes the
flapper plate (7) which is connected to the torque tube (6) External control electronics (separate order)
via a bolt to move from the central position between the External control electronics (servo amplifier) serve the
two control nozzles (8), and a pressure differential is actuation of the valve, amplifying an analog input signal
created across the front sides of the control spool (3). (command value) so that with the output signal, the servo
The pressure differential results in the control spool valve is actuated in a flow-controlled form.
changing its position, which results in the pressure port For the limitation of the electric data, a safety barrier is to
being connected to one actuator port and, at the same be connected between valve and amplifier (see page 7).
time, the other actuator port being connected to the
return flow port.

1
4
5
6
7
8
2

9 3

A (T) B
P
Type 4WS2EM 6 …XL…

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Technical data
(for applications outside these values, please consult us!)

General
Installation position Any - ensure that during start-up of the system, the valve is
supplied with sufficient pressure (≥ 10 bar)
Surface protection ▶▶ Valve body, cover, filter screw Nitro-carburated
▶▶ Cap Anodized
Storage temperature range °C +5 … +40
Maximum storage time Years 1
Ambient temperature range °C –30 … +80
Weight kg 1.1

Hydraulic
Operating pressure ▶▶ Ports P, A, B bar 10 … 210 or 10 … 315
Return flow pressure ▶▶ Port T bar Pressure peaks < 100 static < 10
Hydraulic fluid See table page 6
Hydraulic fluid temperature range °C –15 ... +80; preferably +40 ... +50
Viscosity range mm2/s 15 ... 380; preferably 30 ... 45
Maximum admissible degree of contamination of the hydraulic fluid, Class 18/16/13 1)

cleanliness class according to ISO 4406 (c)

Zero flow qV,L l/min see characteristic curve on page 10
Rated flows qv nom 2; 5; 10; 15; 20; 25
(tolerance ±10% with valve pressure differential ∆p = 70 bar l/min
Maximum control spool stroke with mechanical end % 120 … 170
position (in case of error) related to nominal stroke
Feedback system mechanical
Hysteresis (dither-optimized) % ≤ 1.5
Range of inversion (dither-optimized) % ≤ 0.2
Response sensitivity (dither-optimized) % ≤ 0.2
Pressure amplification with 1% control spool stroke change % of pP ≥ 50
(from the hydraulic zero point)
Zero adjustment flow % ≤ 3, long-term ≤ 5
across the entire operating pressure range
Zero shift upon change of:
▶▶ Hydraulic fluid temperature % / 20 °C ≤ 1
▶▶ Ambient temperature % / 20 °C ≤ 1
▶▶ Operating pressure 80 … 120% of pP % / 100 bar ≤ 2
▶▶ Return flow pressure 0 … 10% of pP % / bar ≤ 1

1) The cleanliness classes specified for the components must be qV,L = zero flow in l/min
adhered to in hydraulic systems. Effective filtration prevents faults qV nom = nominal flow in l/min
and simultaneously increases the life cycle of the components. pP = operating pressure in bar
Available filters can be found at www.boschrexroth.com/filter.

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Technical data
(for applications outside these values, please consult us!)

Hydraulic fluid Classification Suitable Standards Data sheet

sealing materials
Mineral oils HL, HLP, HLPD, HVLP, HVLPD NBR, FKM DIN 51524 90220
Bio-degradable ▶▶ Insoluble in water HETG FKM
ISO 15380
HEES FKM 90221
▶▶ Soluble in water HEPG FKM ISO 15380

Important information on hydraulic fluids: ▶▶ The ignition temperature of the hydraulic fluid used must be at
▶▶ For further information and data on the use of other hydraulic least 150 °C.
fluids, please refer to the data sheets above or contact us.
▶▶ There may be limitations regarding the technical valve data
(temperature, pressure range, life cycle, maintenance
intervals, etc.).

Electric
Protection class according to EN 60529 IP 65 with mating connector correctly mounted and locked
Type of signal analog
Nominal flow per coil (command value 100%) mA 30
Resistance per coil Ω 85

Notice:
In case of control using non-Rexroth amplifiers, we recommend
a superimposed dither signal.

Information on explosion protection

Area of application according to Directive 2014/34/EU II 3G
Type of protection according to EN IEC 60079-0 / EN 60079-11 Ex ic IIC T4 Gc
"IECEx Certificate of Conformity" IECEx BVS 18.0045X
Power supply of the valve only from intrinsically safe electric circuits Maximum values see page 7
Special application conditions for safe application see ambient and hydraulic fluid temperature range page 5

External control electronics

Recommended safety barrier see page 7
Servo amplifier in modular design analog Type VT 11021 according to data sheet 29743

Important notice:
The external servo amplifier and the safety barrier must be
operated outside the potentially explosive atmospheres.

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Electrical connection

The coils can be connected in parallel connection or individual control.

▶▶ Parallel connection

1 2 5.1 5.2 3 4
A C B D
A 1 Servo amplifier
C 2 Safety barrier
B 3 Valve, coil A
D 4 Valve, coil B
E 5.1 Non-explosive area
n.c.
F 5.2 Explosive area
n.c.

PA PA

Power supply of the valve only from intrinsically safe ▶▶ Umax V 15

electric circuits with the following maximum values ▶▶ Imax mA 153
▶▶ Pmax mW 570
Recommended safety barrier Type 9001/02-133-150-101 (company Stahl) or
Z915 (company Pepperl+Fuchs)

▶▶ Individual control

3 4
5.1 5.2
A C B D
A 1 Servo amplifier
C 2 Safety barrier
PA PA
B 3 Valve, coil A
1 2
D 4 Valve, coil B
E 5.1 Non-explosive area
n.c.
F 5.2 Explosive area
n.c.

PA PA

Power supply of the valve only from intrinsically safe ▶▶ Umax V 9.3 12.5
electric circuits with the following maximum values ▶▶ Imax mA 205 90
▶▶ Pmax mW 476 282
Recommended safety barrier 9002/77-093-300-001 Z966 (company Pepperl+Fuchs)
(company Stahl)

The electric control with plus (+) at A and B and minus (–)

Notice: at C and D results in direction of flow P → A and B → T.
Only use approved cables and lines for intrinsically safe electric Inverted electric control results in direction of flow P → B and A → T.
circuits. Pins E and F at the connector are not connected.

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Characteristic curves
(measured with HLP 32, ϑoil = 40 °C ± 5 °C)

Tolerance field of the flow/signal function at constant valve pressure differential ∆p

Standard Special version "-100"

P → A; B → T P → A; B → T
110 100
100
80
80
60
60
40 1
40 1
20
← Flow in % →

← Flow in % →
20 -100 -80 -60 -40 -20 -5
-100 -80 -60 -40 -20 -5
5 20 40 60 80 100
5 20 40 60 80 100 20
20
40
40 2
2 60
60
80
80
100
100
110 120
P → B; A → T P → B; A → T
← Command value in % → ← Command value in % →

Special version "-102"

P → A; B → T
120

100

80

60
1
40
← Flow in % →

20
-100 -80 -60 -40 -20 -5

5 20 40 60 80 100
20

40
2
60

80 1 Tolerance field
2 Typical flow curve
100
P → B; A → T
← Command value in % →

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Characteristic curves
(measured with HLP 32, ϑoil = 40 °C ± 5 °C)

Flow/load function
(tolerance ±10%) with 100% command value signal
50 6 Nominal flow
40 5 1 2 l/min
30 4 2 5 l/min
25 3 10 l/min
20 3 4 15 l/min
15 5 20 l/min
Flow in l/min →

6 25 l/min
10 2
8
6 Notes:
5 ▶▶ Flow values in the maximum command value range
4 1 (see tolerance field of the flow/signal function)
▶▶ ∆p = pP – pL – pT
3
∆p valve pressure differential
pP inlet pressure
2 pL load pressure
pT return flow pressure

1
20 30 40 50 60 70 80 100 200 300

Valve pressure differential in bar →

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Characteristic curves
(measured with HLP 32, ϑoil = 40 °C ± 5 °C)

Zero flow (with control spool overlap "E", measured without dither signal)

2.0
6
1,8
5
1,6
4
1,4
Zero flow in l/min →

3
1,2
2
1.0
1
0,8 Nominal flow
1 2 l/min
0,6
2 5 l/min
0.4 3 10 l/min
4 15 l/min
0.2 5 20 l/min
6 25 l/min
0
0 50 100 150 200 250 300 350
Operating pressure in bar →

Transition function with pressure rating 315 bar,

step response without flow

40 bar
100
Control spool stroke in % →

70 bar

80 140 bar
210 bar
60
315 bar

40

20

0
2 4 6 8 10 12
Time in ms →

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Characteristic curves
(measured with HLP 32, ϑoil = 40 °C ± 5 °C)

Frequency response with pressure rating 315 bar, stroke frequency without flow
(measured with pilot pressure pSt = 315 bar)
5 –315 ±5 %

0 –270 ±25 %
Amplitude ratio in dB →

–3 ±100 %
–225

Phase angle in ° →

–5

–10 –180

–15 –135

–20 –90

–25 –45

–30 0
10 20 30 50 100 200 300 500 1000
Frequency in Hz →

Dependency of the frequency f at –90° on the operating pressure p

and the inlet amplitude
100 40 bar Notice:
90 The output signal corresponds to
70 bar
the control spool stroke with
80
flow without load pressure
Inlet amplitude in % →

140 bar
70
210 bar
60
315 bar
50
1) Correction factors with qV nom:
40
25 l/min 1.00
30
20 l/min 1.00
20
15 l/min 0.95
10 10 l/min 0.90

0 5 l/min 0.85
100 150 200 250 300 350 2 l/min 0.80
Frequency with phase angle –90° in Hz 1) →

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Dimensions
(dimensions in mm)

2 63.5 64
35
80

58
45

A P(T) B
8

3 4 5 8 9
80
66
7 14 7
6
2

T
A
46

B
Ø4.5…7.0

P
1
148 15

10
80
19

F1 F2
T
8

0,01/100
47

A B Rzmax 4
P

Required surface quality

F4 G F3 of the valve contact surface

For item explanations, valve mounting screws and

subplates, see page 13. Notes:
The dimensions are nominal dimensions which are subject to
tolerances.

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Dimensions

1 Space required for removing the mating connector, Subplates (separate order) with porting pattern according to
additionally observe the bending radius of the connection line ISO 4401-03-02-0-05, see data sheet 45100.

2 Cap
3 Valve mounting screws (included in the scope of delivery) Notice:
Only use valve mounting screws with the subsequently listed Subplates are no components in the sense of Directive 2014/34/
thread diameters and strength properties. Observe the EU and can be used after the manufacturer of the overall system
screw-in depth. has conducted an assessment of the risk of ignition. The "G...J3"
4 hexagon socket head cap screws ISO 4762 - M5 x 50 - 10.9 versions are free from aluminum and/or magnesium and
(Friction coefficient µtotal = 0.09 … 0.14) galvanized.
Tightening torque MA = 7 Nm ±10%
4 Identical seal rings for ports P, A, B and T
5 Name plate
6 Mating connector (separate order, see page 14)
7 Connection line, further information on page 7
8 Filter
9 Plug screw
10 Machined valve contact surface;
Porting pattern according to ISO 4401-03-02-0-05
(however, without locating hole)

Flushing plate with porting pattern according to ISO 4401-03-02-0-05

(dimensions in mm)

Symbol
P A B T

Ordering code and further information

▶▶ Material number R901541300
▶▶ Weight 0.6 kg
▶▶ Identical seal rings for ports P, A, B and T
35.5
30.5

▶▶ Mounting screws (included in the scope of delivery)

For reasons of stability, exclusively the following mounting screws
are to be used:
4 hexagon socket head cap screws ISO 4762 - M5 x 40 - 10.9
(Friction coefficient µtotal = 0.09 … 0.14)
9.5

Tightening torque MA = 7 Nm ±10%

65
11.5
Notice:
Before assembly and operation, observe the information in the
5.75

operating instructions 29564-XL-B. P

A
44

B
T

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Accessories (separate order)

Mating connectors and cable sets

Item 1) Designation Version Short designation Material number Data sheet
6 Mating connector; straight, metal 6P KPTC6 R901043330 08006
for valves with round connector, 6-pole

1) See dimensions on page 12.

Further information

▶▶ Subplates Data sheet 45100

▶▶ Hydraulic fluids on mineral oil basis Data sheet 90220
▶▶ Environmentally compatible hydraulic fluids Data sheet 90221
▶▶ Mating connectors and cable sets for valves and sensors Data sheet 08006
▶▶ Analog amplifier module type VT 11021 Data sheet 29743
▶▶ Use of non-electrical hydraulic components in an explosive environment (ATEX) Data sheet 07011
▶▶ Selection of filters www.boschrexroth.com/filter
▶▶ Information on available spare parts www.boschrexroth.com/spc

Bosch Rexroth AG © All rights reserved to Bosch Rexroth AG, also regarding any disposal,

Industrial Hydraulics exploitation, reproduction, editing, distribution, as well as in the event of
Zum Eisengießer 1 applications for industrial property rights.
97816 Lohr am Main, Germany The data specified above only serve to describe the product. No statements
Phone +49 (0) 93 52 / 40 30 20 concerning a certain condition or suitability for a certain application can be
my.support@boschrexroth.de derived from our information. The information given does not release the user
www.boschrexroth.de from the obligation of own judgment and verification.
It must be remembered that our products are subject to a natural process of
wear and aging.

Bosch Rexroth AG, RE 29564-XL, edition: 2020-11

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Notes

Bosch Rexroth AG © All rights reserved to Bosch Rexroth AG, also regarding any disposal,

Industrial Hydraulics exploitation, reproduction, editing, distribution, as well as in the event of
Zum Eisengießer 1 applications for industrial property rights.
97816 Lohr am Main, Germany The data specified above only serve to describe the product. No statements
Phone +49 (0) 93 52 / 40 30 20 concerning a certain condition or suitability for a certain application can be
my.support@boschrexroth.de derived from our information. The information given does not release the user
www.boschrexroth.de from the obligation of own judgment and verification.
It must be remembered that our products are subject to a natural process of
wear and aging.

RE 29564-XL, edition: 2020-11, Bosch Rexroth AG

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Notes

Bosch Rexroth AG © All rights reserved to Bosch Rexroth AG, also regarding any disposal,

Industrial Hydraulics exploitation, reproduction, editing, distribution, as well as in the event of
Zum Eisengießer 1 applications for industrial property rights.
97816 Lohr am Main, Germany The data specified above only serve to describe the product. No statements
Phone +49 (0) 93 52 / 40 30 20 concerning a certain condition or suitability for a certain application can be
my.support@boschrexroth.de derived from our information. The information given does not release the user
www.boschrexroth.de from the obligation of own judgment and verification.
It must be remembered that our products are subject to a natural process of
wear and aging.

Bosch Rexroth AG, RE 29564-XL, edition: 2020-11