RE 29173, edition: 2015-10, Bosch Rexroth AG
Proportional pressure reducing valve,
pilot operated,
with DC motor operation
Features
▶ Pressure reduction at ports A or P① with pressure
limitation
▶ For subplate mounting
▶ Porting pattern according to ISO 4401-03-02-0-05
▶ As a sandwich plate valve
▶ Self-locking DC motor → on failure of the supply voltage
or error message from the control electronics, the
pressure setting is retained
▶ Position feedback
▶ Built-in pressure monitoring, optional
▶ Size 6
▶ Component series 1X
▶ Maximum operating pressure 210bar
▶ Maximum flow 30 l/min
RE 29173 
Edition: 2015-10
Replaces: 2014-10
H7121
Type DRS and ZDRS
Contents
Features 1
Ordering codes 2
Symbols 3
Function, section 4, 5
Technical data 6, 7
Characteristic curves 8 ... 11
Dimensions 12 ... 14
Electrical connection 14, 15
More information 16
Contents
Features 1
Ordering codes 2
Symbols (① = component side, ② = plate side) 3
Function, section: Type DRS 4
Function, section: Type ZDRS 5
Technical data
(For applications outside these parameters, please consult
us!) 6
Technical data 7
(For applications outside these parameters, please consult
us!) 7
Characteristic curves
(measured with HLP46, ϑ
oil
= 40 ±5 °C ) 8
Characteristic curves
(measured with HLP46, ϑ
oil
= 40 ±5 °C ) 9
Characteristic curves
(measured with HLP46, ϑ
oil
= 40 ±5 °C ) 10
Characteristic curves
(measured with HLP46, ϑ
oil
= 40 ±5 °C ) 11
Dimensions: Type DRS
(dimensions in mm) 12
Dimensions: Type ZDRS
(dimensions in mm) 13
Dimensions 14
Electrical connection
(dimensions in mm) 14
Electrical connection
(dimensions in mm) 15
More information 16
2/16 DRS; ZDRS | Proportional pressure reducing valve
Bosch Rexroth AG, RE 29173, edition: 2015-10
Ordering codes
01 Subplate mounting no code
Sandwich plate Z
02 Pressure reducing valve with DC motor actuation DRS
03 Size 6 6
Pressure reduction
04 In channel A (subplate mounting) no code
In channel P① (sandwich plate valve) VP
05 Component series 10 … 19 (10 … 19: unchanged installation and connection dimensions) 1X
Pressure rating
06 50 bar 50
100 bar 100
210 bar 210
07 Without pressure transducer on device A
With pressure transducer on device (only version “100”) S
08 Without check valve M
Supply voltage of the control electronics
09 Direct voltage 24 V G24
Electrical connection
10 Without mating connector; connector type GO51FAVM K32
1)
Seal material
11 NBR seals M
FKM seals V
Observe compatibility of seals with hydraulic fluid used! (Other seals on request)
12 With position feedback G
13 Further details in the plain text *
01 02 03 04 05 06 07 08 09 10 11 12 13
DRS 6 – 1X / M G24 K32 G *
1)
For mating connectors, separate order, see page 14.
Notice: Preferred types and standard units are
contained in the EPS (standard price list).
Proportional pressure reducing valve | DRS: ZDRS 3/16
RE 29173, edition: 2015-10, Bosch Rexroth AG
Symbols (① = component side, ② = plate side)
Type DRS Type ZDRS
Version “A”(without pressure transducer) Version “A”(without pressure transducer)


Version “S” (with pressure transducer) Version “S” (with pressure transducer)


T
A
P
B
561691
17
15
4
12
7
11
8
10
2
31413 18
4/16 DRS; ZDRS | Proportional pressure reducing valve
Bosch Rexroth AG, RE 29173, edition: 2015-10
Function, section: Type DRS
Valves of type DRS are pilot operated 3-way pressure
reducing valves with pressure limitation of the actuator.
They are used for reducing a system pressure.
Set-up
The valves consist of three main assemblies:
▶ Pilot control valve (1)
▶ DC motor (2) with position feedback
▶ Main valve (3) with main spool (4)
▶ With or without pressure transducer, optional (18)
Function
▶ Setting of the pressure to be reduced in channel A
based on the command value via the DC motor (2).
▶ If port P is depressurized, spring (17) holds the main
spool (4)
in the starting position → connection from
port A to T open, port P to A blocked.
▶ Pressure connection from port P to the ring channel
(5). Pilot oil flows through bore (6) via the flow control-
ler (7) into the pilot control chamber (16), via the
nozzle (8), the throttle gap (9) into the chamber (10)
and through the bores (11, 12) to port T
Pressure reduction
▶ Build-up of the pilot pressure in the pilot control cham-
ber (16) as function of the command value.
▶ Movement of the main spool (4) to the right, hydraulic
fluid flows from P to A
▶ Actuator pressure pending in port A to the spring cham-
ber (15) via channel (13) and nozzle (14).
▶ Increase in the pressure in port A to the command
pressure set leads to the movement of the main spool
(4) to the left into the control position. The pressure in
port A is almost identical with the set pressure at pilot
control valve (1).
Pressure limitation does not work if contaminated.
▶ If the pressure in port A exceeds the command pres-
sure set, the main spool (4) is moved further to the left.
▶ This closes the connection from P to A, opens the
connection from P to T and limits the pressure pending
in port A in accordance with the command value set.
Pressure monitoring
For valves with built-in pressure transducers, this is con-
nected to the electronics system and used for recording
and monitoring the pressure set. Another alternative is a
valve without a built-in pressure transducer, but with a
pressure measurement sandwich plate. (For example
applications, see data sheet 62003)
Notice:
If the voltage supply to the control electronics is
switched off or fails, the DC motor stays in its current
position and therefore the last pressure set is also
retained if the hydraulic supply is in place.
Type DRS 6 -1X/...
A
A (P)
B
T
A
P
B
T
1
5
616
93
14
13
412
7
118
10
2
1715
18
Proportional pressure reducing valve | DRS: ZDRS 5/16
RE 29173, edition: 2015-10, Bosch Rexroth AG
Function, section: Type ZDRS
Type ZDRS 6 VP-1X/...
Valves of type ZDRS are pilot operated 3-way pressure
reducing valves with pressure limitation of the actuator.
They are used for reducing a system pressure.
Set-up
The valves consist of three main assemblies:
▶ Pilot control valve (1)
▶ DC motor (2) with position feedback
▶ Main valve (3) with main spool (4)
▶ With or without pressure transducer, optional (18)
Function
▶ Setting of the pressure to be reduced in channel A
based on the command value via the DC motor (2).
▶ If port P is depressurized, spring (17) holds the main
spool (4)
in the starting position → connection from
port A to T is open, port P to A blocked
▶ Pressure connection from port P to the ring channel
(5). Pilot oil flows through bore (6) via the flow control-
ler (7) into the pilot control chamber (16), via the
nozzle (8) and the throttle gap (9) into the chamber
(10) and through the bores (11, 12) to port T
Pressure reduction
▶ Build-up of the pilot pressure in the pilot control cham-
ber (16) as function of the command value.
▶ Movement of the main spool (4) to the right, hydraulic
fluid flows from P to A
▶ Actuator pressure pending in port A to the spring cham-
ber (15) via channel (13) and nozzle (14).
▶ Increase in the pressure in port A to the command
pressure set leads to the movement of the main spool
(4) to the left into the control position. The pressure in
port A is almost identical with the set pressure at pilot
control valve (1).
Pressure limitation does not work if contaminated.
▶ If the pressure in port A (P①) exceeds the command
pressure set, the main spool (4) is moved further to
the left.
▶ This closes the connection from P to A (P①) , opens
the connection from P① to T and limits the pressure
pending in port A (P①) in accordance with the com-
mand value set.
Pressure monitoring
For valves with built-in pressure transducers, this is con-
nected to the electronics system and used to record and
monitor the pressure set in channel P①. Another alterna-
tive is a valve without a built-in pressure transducer, but
with a pressure measurement sandwich plate. (For exam-
ple applications, see data sheet 62003)
Notice:
If the voltage supply to the control electronics is
switched off or fails, the DC motor stays in its current
position and therefore the last pressure set is also
retained if the hydraulic supply is in place.
6/16 DRS; ZDRS | Proportional pressure reducing valve
Bosch Rexroth AG, RE 29173, edition: 2015-10
Technical data
(For applications outside these parameters, please consult us!)
1)
Pressures > 10 can destroy the motor.
2)
The cleanliness classes stated for the components need to be
maintained in hydraulic systems. Effective filtration prevents
faults and at the same time increases the service life of the
components.
For the selection of the filters see www.boschrexroth.com/filter.
3)
By adjusting the zero point and the range in the electronics
system, type VT-MRMA1-1-1X/V0/0, the manufacturing tolerance
of the complete unit (valve + electronics) can be reduced.
4)
T
u
+ T
g
measured with standing hydraulic fluid column <5liters
Hydraulic
Maximum operating
pressure
▶ Port P, P② bar 250
▶ Port P①, A, B bar 210
▶ Port T bar separately to tank
1)
at zero pressure (volume flow 30 l/min
possible)
Maximum set pressure
in channel P① and A
▶ Pressure rating 50 bar bar 50
▶ Pressure rating 100 bar bar 100
▶ Pressure rating 210 bar bar 210
Minimum pressure in channel P or P② bar
Set pressure in channel A or channel P
① plus 20 bar
Minimum set pressure with command value 0 in channel
A or P①
bar see characteristic curves page 10 (maximum 3 bar)
Maximum flow l/min 30
Pilot flow l/min 0.65
Hydraulic fluid see table on page 7
Maximum permissible degree of contamination of the
hydraulic fluid, cleanliness class according to ISO 4406 (c)
Class 20/18/15
2)
Hydraulic fluid temperature range °C -20 … +80
Viscosity range mm
2
/s 15 … 280
Hysteresis % < 2 of the maximum pressure which can be set
Repetition accuracy % < ± 1 of the maximum pressure which can be set
Linearity % < 2 of the maximum pressure which can be set
Response sensitivity % < 0.5 of the maximum pressure which can be set
Valve manufacturing tolerance of the command value
pressure characteristic curve,
% < ± 6 of the maximum pressure which can be set
3)
Step response T
u
+ T
g
4)
▶ 0% → 100%,
100% → 0%
ms < 500
General
Installation position Any (preferably horizontal)
Weight ▶ Type DRS kg 1.6
▶ Type ZDRS kg 1.5
Storage temperature range °C -20 … +80
Ambient temperature range °C -20 … +60
Notice:
The technical data were determined at a viscosity of 46 mm²/s
(HLP46; 40°C).
Proportional pressure reducing valve | DRS: ZDRS 7/16
RE 29173, edition: 2015-10, Bosch Rexroth AG
Technical data
(For applications outside these parameters, please consult us!)
When establishing the electrical connection, the protective
earthing conductor (PE
) has to be connected correctly.
Electrical: Valve
Nominal voltage V 18
Rated current A 0.5 ± 20%
Maximum continuous current A 0.5
Connection resistance
Ω
9.9
Winding temperature
°C approx. 20
K 100
Protection class of the valve according to EN 60529 IP 65 (with mating connector mounted and locked)
Electrical: Control electronics
Control electronics Amplifier type VT-MSPA1-11-1X/V0/0 in modular design
(separate order) based on data sheet 30214
Notices:
The valves must not be used for safety-related machine func-
tions as only the electrical area is secured, not the hydraulic one.
This means that if the hydraulic pressure in P falls to 0 bar, the
actuator pressure (A) or secondary pressure (P①) is also 0.
Hydraulic fluid Classification Suitable sealing materials Standards Data sheet
Mineral oils HL, HLP NBR, FKM DIN 51524 90220
Bio-degradable ▶ Insoluble in water HEES FKM ISO15380 90221
▶ soluble in water HEPG FKM ISO15380
Flame-resistant ▶ water-free HFDU FKM ISO 12922 90222
▶ containing water HFC (Fuchs Hydrotherm 46M,
Petrofer Ultra Safe 620)
NBR ISO 12922 90223
Important Information on hydraulic fluids:
▶ For more information and data on the use of other hydraulic
fluids, please refer to the above data sheets or contact us!
▶ There may be limitations regarding the technical valve data
(temperature, pressure range, life cycle, maintenance intervals,
etc.)!
▶ The flash point of the hydraulic fluid used must be 40 K higher
than the maximum solenoid surface temperature.
▶ Flame-resistant – containing water:
– Maximum pressure differential 210 bar, otherwise,
increased cavitation.
– Pressure pre-loading at the tank port >20% of the pressure
differential, otherwise increased cavitation
– Life cycle as compared to operation with mineral oil HL,
HLP 30to100%
▶ Bio-degradable and flame resistant: When using these hydraulic
fluids that are simultaneously zinc-solvent, zinc may accumulate
(700 mg zinc per pole tube).
30
20
10
0510 15
20
25
30
40
1
2
30
20
10
0510 15
20
25
30
40
1
2
3
2
1
0
51015202
0
5
3
4
8/16 DRS; ZDRS | Proportional pressure reducing valve
Bosch Rexroth AG, RE 29173, edition: 2015-10
Characteristic curves
(measured with HLP46, ϑ
oil
= 40 ±5 °C )
∆p-q
V
characteristic curves
Flow in l/min → Flow in l/min →
Flow in l/min →
Pressure differential in bar →
Pressure differential in bar →Pressure differential in bar →
Type ZDRS (P② → P①)
Type ZDRS
Type DRS (P → A)
Notice:
The pressure differential shown corresponds to the
minimum pressure available in port P (P②) minus the
maximum pressure to be controlled in port A (P①).
1 100/210 bar
2 50 bar
3 A① →A②
4 B① →B②
5 T① →T②
80
40
20
60
020406080 100
100
150
100
50
0
20 40
60 80
100
210
200
40
20
10
30
020406080 100
50
Proportional pressure reducing valve | DRS: ZDRS 9/16
RE 29173, edition: 2015-10, Bosch Rexroth AG
Pressure in port P① or A depending on the command
value
Pressure rating 50 bar
Pressure rating 210 bar
Pressure rating 100 bar
Command value in % →
Command value in % →
Command value in % →
Pressure in port P① or A
in bar →
Pressure in port P① or A
in bar →
Pressure in port P① or A
in bar →
Characteristic curves
(measured with HLP46, ϑ
oil
= 40 ±5 °C )
10
10 1020 2030 300
2
4
6
8
0
12
14
10
10 1020 2030 300
2
4
6
8
0
12
14
13
10/16 DRS; ZDRS | Proportional pressure reducing valve
Bosch Rexroth AG, RE 29173, edition: 2015-10
Minimum set pressure in port P① or A with command
value 0V (without counter pressure in channel T or T①)
Pressure rating 50 bar Pressure rating 100 bar and 210 bar
← Flow in l/min → ← Flow in l/min →
Minimum set pressure
in bar →
Minimum set pressure
in bar →
Characteristic curves
(measured with HLP46, ϑ
oil
= 40 ±5 °C )
Type DRS A → T P → A
Type ZDRS P① → T② P② → P①
Type DRS A → T P → A
Type ZDRS P① → T② P② → P①
30
0
10
20
30
40
50
20 10 0102
03
0
30
0
20
40
60
80
100
20 10 0102
03
0
30
0
40
80
120
160
210
20 10 0102
03
0
Proportional pressure reducing valve | DRS: ZDRS 11/16
RE 29173, edition: 2015-10, Bosch Rexroth AG
Pressure in port P① or A depending on the flow
Pressure in port P① or A
in bar →
Pressure in port P① or A
in bar →
Pressure in port P① or A
in bar →
Characteristic curves
(measured with HLP46, ϑ
oil
= 40 ±5 °C )
Pressure rating 50 bar
Pressure rating 210 bar
Pressure rating 100 bar
← Flow in l/min →
← Flow in l/min →
← Flow in l/min →
Type DRS A → T P → A
Type ZDRS P① → T② P② → P①
Type DRS A → T P → A
Type ZDRS P① → T② P② → P①
Type DRS A → T P → A
Type ZDRS P① → T② P② → P①
Rzmax 4
0,01/100






















F1
F3
F2
G
T
P
BA
87
47
8
F4
29
8
12/16 DRS; ZDRS | Proportional pressure reducing valve
Bosch Rexroth AG, RE 29173, edition: 2015-10
1 DC motor
2 valve housing
3 Name plate
4 Identical seal rings for ports A, P, T and blind counterbore B
5 Mating connector, separate order, see page 14.
6 Space required to remove the mating connector
7 Space required for connecting cable
Note: The mating connector can be fitted offset by 4 x 90°.
8 Porting pattern according to ISO 4401-03-02-0-05
(Deviating from the standard, without locating pin)
9 Blind bore hole (port B)
10 Pressure transducer for version “S”
11 Space required to remove the mating connector
Dimensions: Type DRS
(dimensions in mm)
Required surface quality of the valve
contact surface
For valve mounting screws and subplates, see page 14.
Rzmax 4
0,01/100
F1
F3
F2
G
T
P
BA
87
47
8
F4
25
8



















Proportional pressure reducing valve | DRS: ZDRS 13/16
RE 29173, edition: 2015-10, Bosch Rexroth AG
1 DC motor
2 valve housing
3 Name plate
4 Identical seal rings for ports A, P, T and blind counterbore B
5 Mating connector, separate order, see page 14.
6 Space required to remove the mating connector
7 Space required for connecting cable
Note: The mating connector can be fitted offset by 4 x 90°.
8 Porting pattern according to ISO 4401-03-02-0-05
(Deviating from the standard, without locating pin)
9 Blind bore hole (port B)
10 Pressure transducer for version “S”
11 Space required to remove the mating connector
Dimensions: Type ZDRS
(dimensions in mm)
Required surface quality
of the valve contact surface
For valve mounting screws and subplates, see page 14.







14/16 DRS; ZDRS | Proportional pressure reducing valve
Bosch Rexroth AG, RE 29173, edition: 2015-10
Valve mounting screws (separate order)
Type Quantity Hex socket head cap screws Material number
DRS 4 ISO 4762 - M5 x 50 - 10.9-flZn-240h-L
(friction coefficient µ
total
= 0.09 … 0.14);
tightening torque M
A
= 7 Nm ±10%
R913000064
or
4 4 hexagon socket head cap screws ISO 4762 - M5 x 50 - 10.9
(friction coefficient µ
total
= 0.12 … 0.17);
tightening torque M
A
= 8.1 Nm ±10%
Not included in the Rexroth
delivery range
ZDRS 4 ISO 4762 - M5 - 10.9-flZn-240h-L
(friction coefficient µ
total
= 0.09 … 0.14);
tightening torque M
A
= 7 Nm ±10%,
See notes
or
4 ISO 4762 - M5 - 10.9
(friction coefficient µ
total
= 0.12 … 0.17);
tightening torque M
A
= 8.1 Nm ±10%
Not included in the Rexroth
delivery range
Dimensions
Subplates(separate order)
Size Data sheet Material number
6 45052 –
Notices:
▶ The tightening torque of the hexagon socket head cap screws
refers to the maximum operating pressure.
▶ Type ZDRS: Length and tightening torque of the valve mount-
ing screws must be calculated according to the components
mounted under and over the sandwich plate valve.
Mating connector (separate order)
Material no. R900021448
(Plastic version)
Electrical connection
(dimensions in mm)
1 Position feedback +
2 Position feedback output
3 Position feedback -
4 Motor +
5 Motor –
PE = GND
1
2
3
4
Proportional pressure reducing valve | DRS: ZDRS 15/16
RE 29173, edition: 2015-10, Bosch Rexroth AG
Voltage Current (two-wire system)
1 → auxiliary energy + (+ U
B
) 1 → auxiliary energy + (+ U
B
)
2 → n.c. 2 → n.c.
3 → auxiliary energy – (0V) 3 → auxiliary energy – (0V)
4 → output signal 4 → n.c.
Pressure transducer on device, Version “S”
(4-pole M12 connector, view of contact side)
Mating connectors for pressure transducer
Technical data Designation Material no.
Current carrying capacity 4 A




04 POL (with 2 m cable) R900773031
Temperature range –25 … 90°C 04 POL (with 5 m cable) R900779498
Protection class IP 67
Contacts CuZn
Contact surface gold-plated





04 POL (with 2 m cable) R900779504
Housing TPU 04 POL (with 5 m cable) R900779503
Seal material FKM
Fitting CuZn/Ni
Wire cross-section 4 x 0.34mm
Jacket material PUR
Screening
on connector
side not applied



04 POL (without cable),
protection class IP68
R900773042
Sleeve diameter Ø 5.0 mm
Sleeve color black
Bending radius for
dynamic use min. 50 mm










04 POL (without cable),
protection class IP68
R900779509
Electrical connection
(dimensions in mm)
Bosch Rexroth AG, RE 29173, edition: 2015-10
16/16
DRS; ZDRS | Proportional pressure reducing valve
Bosch Rexroth AG
Hydraulics
Zum Eisengießer 1
97816 Lohr am Main, Germany
Phone +49 (0) 93 52 / 18-0
documentation@boschrexroth.de
www.boschrexroth.de
© This document, as well as the data, specifications and other information set
forth in it, are the exclusive property of Bosch Rexroth AG. It may not be
reproduced or given to third parties without the consent of Bosch Rexroth AG.
The data specified above only serve to describe the product. No statements
concerning a certain condition or suitability for a certain application can be
derived from our information. The information given does not release the user
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.
More information
▶ Subplates Data sheet 45052
▶ Analog amplifier module typeVT-MRMA1-1-1X/V0/0 Data sheet 30214
▶ Compact power supply units VT-NE30 Data sheet 29929
▶ Pressure transducer with integrated electronics, type HM 17 Data sheet 30269
▶ Application example: Analog pressure adjustment system with pressure monitoring Data sheet 62003
▶ Mineral oil-based hydraulic fluids Data sheet 90220
▶ Environmentally compatible hydraulic fluids Data sheet 90221
▶ Flame-resistant, water-free hydraulic fluids Data sheet 90222
▶ Hydraulic valves for industrial applications Data sheet 07600-B
▶ General product information on hydraulic products Data sheet 07008
▶ Assembly, commissioning and maintenance of industrial valves Data sheet 07300
▶ Filter range www.boschrexroth.com/filter