1/14
Information on available spare parts:
www.boschrexroth.com/spc
Proportional pressure relief valve,
direct operated,
decreasing characteristic curve
Type KBPS.8B (High Performance)
Component size 8
Component series A
Maximum operating pressure 420 bar
Maximum flow 2 l/min
RE 18139-05/07.12
Replaces: 11.11
Table of contents Features
H7071
Contents Page
Features 1
Ordering code 2
Preferred types 2
Function, section, symbol 3
Technical data 4, 5
Characteristic curves 6 to 9
Minimum terminal voltage at the coil
and relative duty cycle 10, 11
Unit dimensions 12
Mounting cavity 13
Available individual components 14
– Cartridge valve
– Mounting cavity R/T-8A
–
Direct operated proportional valve for limiting a system pressure
– Suitable for mobile and industrial applications
– Operation by means of proportional solenoid with central
thread and detachable coil
– Fine adjustment of the command value pressure characteris-
tic curve possible from the outside at the control electronics
– Set to the maximum pressure via the adjustment screw
– In case of power failure, maximum set pressure
– Control electronics: Data sheet
• Plug-in proportional amplifier
type VT-SSPA1…
30116
• Analog amplifier type RA… 95230
• BODAS control unit type RC… 95200
2/14 Bosch Rexroth AG Hydraulics
KBPS RE 18139-05/07.12
Ordering code
Preferred types
Type Material number
KBPSB8BA/HCG24C4V-8 R901144800
KBPSL8BA/HCG24C4V-8 R901120007
KBPSR8BA/HCG24C4V R901018607
KBPSL8BA/HCG12C4V R901056361
KBPSL8BA/HCG24C4V R901018602
KBPSL8BA/HCG12K40V R901064385
KBPSN8BA/HCG24K40V R901016229
KBPSP8BA/HCG24K40V R901026207
KBPSR8BA/HCG24K40V R901188705
KBPSP8BA/HCG24K4V R901018593
Proportional pressure relief
valve, direct operated
(pilot control valve)
Pressure rating
up to 30 bar = B
up to 50 bar = C
up to 100 bar = F
up to 150 bar = H
up to 210 bar = L
up to 250 bar = N
up to 315 bar = P
up to 350 bar = R
up to 420 bar = T
Component size 8 = 8
Maximum pressure with command value = 0 = B
Component series = A
High Performance and mounting cavity R/T-8A
= H
(see page 13)
Proportional solenoid, wet-pin = C
Further details in the
plain text
no code = Standard
-8 = Coil 800 mA
(see page 5)
Seal material
V = FKM seals
Attention!
Obs erve compati bili ty of the seals
with the hydrau lic flu id used!
Electrical connection
1)
K4 = Without mating connector, with con-
nector according to DIN EN 175301-803
K40 = Without mating connector, with
connector DT 04-2PA (Deutsch plug)
C4 = Without mating connector, with
connector AMP Junior-Timer
Supply voltage
G12 = Control electronics 12 V DC
G24 = Control electronics 24 V DC
KBPS 8 B A H C V
*
1)
Mating connectors, separate order, see data sheet 08006.
3
5
6
(T)
(P)
2
1
4
2
1
Hydraulics Bosch Rexroth AG
RE 18139-05/07.12 KBPS
3/14
Function, section, symbol
Symbol
General
Valves of type KBPS.8B are direct operated proportional
pressure relief valves (pilot control valves) in seat design and
are used to limit a system pressure. They basically comprise
of the pole tube (3), the solenoid coil (4), the valve seat (5)
and the valve poppet (6).
With command value 0 or in case of power failure, the maxi-
mum pressure is set. Operation by means of a proportional
solenoid with central thread and detachable coil. The sole-
noid‘s interior is connected to the main port ② and filled with
hydraulic fluid. Depending on the electric command value,
these valves can be used to continuously set the system
pressure to be limited.
Basic principle
In the factory, the valves are mechanically set to the maxi-
mum pressure. For the proportional reduction of the system
pressure, a command value is specified at the control elec-
tronics. Depending on the command value, the electronics
actuate the solenoid with electric current.
The proportional solenoid converts the electric current into
mechanical force that acts against the setting spring via the
armature and thus reduces the force on the valve poppet (6).
The valve poppet (6) pushes onto the valve seat (5) and
blocks the connection between main port ① and ②. If the hy-
draulic force on the valve poppet (6) corresponds to the force
difference between setting spring and solenoid force, the
valve controls the set pressure by lifting the valve poppet (6)
off the valve seat and thus enabling hydraulic fluid flow from
main port ① to ②. If the command value is zero, the maxi-
mum pressure is set.
Notice!
Occurring tank pressures (main port ②) are added up to the
set values in the main port ①.
Version
"C4"
Version
"K40"
(with mating connector)
Version
"K4"
4/14 Bosch Rexroth AG Hydraulics
KBPS RE 18139-05/07.12
Technical data (For applications outside these parameters, please consult us!)
general
Weight kg 0.45
Installation position Any - if it is ensured that no air can collect upstream the
valve. Otherwise, we recommend suspended installation of
the valve.
Ambient temperature range °C –20 to +120
Storage temperature range °C –20 to +80
Environmental audits:
Vibration test according to DIN EN 60068-2 / IEC 60068-2 /2 axes (X/Z)
DIN EN 60068-2-6: 05/96 Vibrations, sine-shaped 10 cycles (5 Hz to 2000 Hz back to 5 Hz) with logarithmic
frequency changing speed of 1 octave/min, 5 to 57 Hz, ampli-
tude 1.5 mm (p-p), 57 to 2000 Hz, amplitude 10 g
IEC 60068-2-64: 05/93 Vibrations (random) and
broadband noise
20 to 2000 Hz, amplitude 0.05 g
2
/Hz
(10 g RMS/30 g peak), testing time 30 min
DIN EN 60068-2-27: 03/95 Shocking Half sine 15 g / 11 ms, 3 x in positive, 3 x in negative direc-
tion (a total of 6 individual shocks)
DIN EN 60068-2-29: 03/95 Bump test Half sine 25 g / 6 ms, 1000 x in positive, 1000 x in negative
direction (a total of 2000 individual shocks)
Indication per axis
Climatic test according to EN 60068-2 / IEC 60068-2 (environmental test):
DIN EN 60068-2-1: 03/95 Storage temperature –40 °C, duration 16 h
DIN EN 60068-2-2: 08/94 +110 °C, duration 16 h
DIN EN 60068-2-1: 03/95 Cold test 2 cycles –25 °C, duration 2 h
DIN EN 60068-2-2: 08/94 Dry heating test 2 cycles +120 °C, duration 2 h
IEC 60068-2-30: 1985 Humid heat, cyclic Variant 2/ +25 °C to +55 °C
93 % to 97 % relative humidity, 2 cycles à 24 h
Salt spray test: 720 h according to DIN 50021
→ Coating generally not necessary. If paint is applied nevertheless, the reduced heat dissipation capacity is to be observed.
hydraulic
Maximum operating pressure
1)
(main port ①) bar 420
Maximum admissible return flow pressure
(main port ②)
bar 210
Maximum set pressure
2)
See command value pressure characteristic curves page 6
Minimum set pressure with command value max
3)
See characteristic curves page 8 and 9
Maximum flow l/min 2 (see characteristic curves page 6 and 7)
Hydraulic fluid See page 5
Hydraulic fluid temperature range °C –20 to +80
Viscosity range mm
2
/s 15 to 380
Maximum permitted degree of contamination of the hydraulic
fluid - cleanliness class according to ISO 4406 (c)
Class 20/18/15
4)
1)
Attention! The maximum operating pressure is the total of
set pressure and return flow pressure!
2)
Attention! The valves are set in the factory. In case of
subsequent adjustment, the warranty will become invalid!
3)
If the valve is installed in a mounting cavity made of non-
magnetically conductive material, the minimum set pres-
sure is slightly higher.
4)
The cleanliness classes specified for the components must
be adhered to in hydraulic systems. Effective filtration pre-
vents faults and at the same time increases the service life
of the components.
For the selection of the filters see www.boschrexroth.com/filter.
Hydraulics Bosch Rexroth AG
RE 18139-05/07.12 KBPS
5/14
Technical data (For applications outside these parameters, please consult us!)
hydraulic
Hysteresis
5)
< 4 % of the max. set pressure
Range of inversion
5)
< 0.5 % of the max. set pressure
Response sensitivity
5)
< 0.5 % of the max. set pressure
Manufacturing tolerance of
the command value pressure
characteristic curve
– Command value 100 % < 2 % of the max. set pressure
– Command value 0 < 5 % of the max. set pressure
Step response (T
u
+ T
g
) 0 → 100 % and/or 100 % → 0 ms 70 (depending on the system)
electric
Supply voltage V 12 DC 24 DC "-8" / 24 DC
Maximum control current mA 1760 1200 800
Coil resistance – Cold value at 20 °C Ω 2.3 4.8 11.5
– max. hot value Ω 3.8 7.9 18.9
Switch-on duration % 100
6)
Maximum coil temperature
7)
°C 150
Protection class
according to DIN EN 60529
– Version "K4" IP 65 with mating connector mounted and locked
– Version "K40" IP 69K with mating connector mounted and locked
– Version "C4" IP 66 with mating connector mounted and locked
IP 69K with Rexroth mating connector (material no. R901022127)
Control electronics
(separate order) – Plug-in proportional amplifier type VT-SSPA1…, see data
sheet 30116
– Analog amplifier type RA…, see data sheet 95230
– BODAS control unit type RC…, see data sheet 95200
Design according to VDE 0580
5)
Measured with analog amplifier type RA1-1/10, see data
sheet 95230
6)
In case of use more than 2000 m a.s.l., please consult us.
7)
Due to the surface temperatures of the solenoid coils, the
standards ISO 13732-1 and EN 982 need to be adhered to!
In the electrical connection, the protective earthing
conductor (PE
) must be connected pro per ly.
Hydraulic fluid Classification Suitable sealing materials Standards
Mineral oils HL, HLP FKM DIN 51524
Bio-degradable – Insoluble in water HEES FKM VDMA 24568
– Soluble in water HEPG FKM
Important information on hydraulic fluids!
▶ For more information and data on the use of other hydraulic
fluids refer to data sheet 90220 or contact us!
▶ There may be limitations regarding the technical valve data
(temperature, pressure range, service life, maintenance
intervals, etc.)!
▶ The flash point of the hydraulic fluids used must be 40 K
higher than the maximum solenoid surface temperature.
▶ Bio-degradable: When using bio-degradable hydraulic fl uids
that are simultaneously zinc-solving, zinc may accumulate in
the fluid.
250
200
150
50
0 25 50 75 100
100
0 0,4 0,8 1,2 1,6 2,0
10
30
20
40
0 0,4 0,8 1,2 1,6 2,0
20
80
180
40
100
140
160
60
120
450
350
300
200
150
50
0 25 50 75 100
100
400
250
0 0,4 0,8 1,2 1,6 2,0
20
60
120
40
80
100
0 0,4 0,8 1,2 1,6 2,0
10
30
50
60
20
40
6/14 Bosch Rexroth AG Hydraulics
KBPS RE 18139-05/07.12
Characteristic curves (measured with HLP46, ϑ
Oil
= 40 °C ± 5 °C and 24 V coil)
Command value in % →
Pressure in main port ① depending on the command value. Flow = 0.8 l/min
Pressure in main port ①
in bar
→
Flow in l/min →
Pressure rating 30 bar
Pressure in main port ①
in bar
→
Pressure in main port ①
in bar
→
Pressure in main port ①
in bar
→
Pressure in main port ①
in bar
→
Flow in l/min →
Pressure rating 150 bar
Pressure in main port ① depending on the flow.
(The characteristic curve was measure without coun ter pressure in main port ②.)
Command value in %
→
Pressure in main port ①
in bar
→
Flow in l/min →
Pressure rating 100 bar
Flow in l/min →
Pressure rating 50 bar
0 0,4 0,8 1,2 1,6 2,0
30
120
300
60
150
210
240
90
180
270
0 0,4 0,8 1,2 1,6 2,0
250
400
200
350
100
300
150
50
0 0,4 0,8 1,2 1,6 2,0
120
240
400
200
320
360
80
280
160
40
0 0,4 0,8 1,2 1,6 2,0
80
160
280
120
200
240
40
0 0,4 0,8 1,2 1,6 2,0
120
240
400
200
320
360
80
280
160
40
440
480
Hydraulics Bosch Rexroth AG
RE 18139-05/07.12 KBPS
7/14
Characteristic curves (measured with HLP46, ϑ
Oil
= 40 °C ± 5 °C and 24 V coil)
Flow in l/min →
Pressure rating 250 bar
Flow in l/min →
Pressure rating 350 bar
Flow in l/min
→
Pressure rating 315 bar
Pressure in main port ① depending on the flow.
(The characteristic curve was measure without coun ter pressure in main port ②.)
Flow in l/min
→
Pressure rating 210 bar
Flow in l/min
→
Pressure rating 420 bar
Pressure in main port ①
in bar
→
Pressure in main port ①
in bar
→
Pressure in main port ①
in bar
→
Pressure in main port ①
in bar
→
Pressure in main port ①
in bar
→
0 0,4 0,8 1,2 1,6 2,0
2
6
10
12
16
4
8
14
0 0,4 0,8 1,2 1,6 2,0
2
16
4
8
12
14
6
10
0 0,4 0,8 1,2 1,6 2,0
2
8
20
4
10
14
16
6
12
18
0 0,4 0,8 1,2 1,6 2,0
1
3
2
4
0 0,4 0,8 1,2 1,6 2,0
6
8
10
2
4
12
0 0,4 0,8 1,2 1,6 2,0
1
3
5
6
2
4
7
8/14 Bosch Rexroth AG Hydraulics
KBPS RE 18139-05/07.12
Characteristic curves (measured with HLP46, ϑ
Oil
= 40 °C ± 5 °C and 24 V coil)
Flow in l/min →
Pressure rating 150 bar
Flow in l/min
→
Pressure rating 210 bar
Flow in l/min →
Pressure rating 250 bar
Minimum set pressure in main port ① with command value 100 %.
(The characteristic curve was measure without coun ter pressure in main port ②.)
Flow in l/min →
Pressure rating 30 bar
Flow in l/min →
Pressure rating 100 bar
Flow in l/min
→
Pressure rating 50 bar
Minimum set pressure
in bar
→
Minimum set pressure
in bar
→
Minimum set pressure
in bar
→
Minimum set pressure
in bar
→
Minimum set pressure
in bar
→
Minimum set pressure
in bar
→
0 0,4 0,8 1,2 1,6 2,0
5
10
15
20
25
0 0,4 0,8 1,2 1,6 2,0
5
10
15
20
25
0 0,4 0,8 1,2 1,6 2,0
5
10
15
20
25
30
Hydraulics Bosch Rexroth AG
RE 18139-05/07.12 KBPS
9/14
Flow in l/min →
Pressure rating 315 bar
Flow in l/min
→
Pressure rating 350 bar
Flow in l/min
→
Pressure rating 420 bar
Characteristic curves (measured with HLP46, ϑ
Oil
= 40 °C ± 5 °C and 24 V coil)
Minimum set pressure in main port ① with command value 100 %.
(The characteristic curve was measure without coun ter pressure in main port ②.)
Minimum set pressure
in bar
→
Minimum set pressure
in bar
→
Minimum set pressure
in bar
→
-40
3
-20 0 40 12020
3,5
4
4,5
5
5,5
6
6,5
7
100
75
80
85
90
95
100
105
110
115
60 80
1,45
1,5
1,55
1,6
1,65
1,7
1,75
1,8
1,85
1
2
3
-40
4
-20
0 40 12020
5
6
7
8
9
10
100
75
80
85
90
95
100
105
60 80
1
1,05
1,1
1,15
1,2
1,25
1,3
1
3
2
10/14 Bosch Rexroth AG Hydraulics
KBPS RE 18139-05/07.12
Minimum terminal voltage at the coil and relative duty cycle
Ambient temperature in °C →
Ambient temperature in °C →
Required minimum voltage
at the coil (1)
→
Required minimum voltage
at the coil (1)
→
Reduced duty cycle DC
for I
max
(1.76 A) in % (2) →
Reduced duty cycle ED
for I
max
(1.2 A) in % (2) →
Admissible continuous application
of current in A with 100 % DC (3) →
Admissible continuous application
of current in A with 100 % DC (3) →
– Version "G12"
– Version "G24"
Admissible working range against the ambient temperature
Limited valve performance
Notice!
The characteristic curves have been determined for coils with
valve with medium test block size (80 x 80 x 80 mm), without
flow in calm air.
Depending on the installation conditions (block size, flow, air
circulation, etc.) there may be a better heat dissipation. Thus,
the area of application is broadened.
In single cases, more unfavorable conditions may lead to limi-
tations of the area of application.
-40
4
-20
0 40 12020
6
8
10
12
14
16
100
75
80
85
90
95
100
105
60 80
0,65
0,7
0,75
0,8
0,85
0,9
0,95
1
3
2
Hydraulics Bosch Rexroth AG
RE 18139-05/07.12 KBPS
11/14
Minimum terminal voltage at the coil and relative duty cycle
Ambient temperature in °C →
Required minimum voltage
at the coil (1)
→
Reduced duty cycle DC
for I
max
(0.8 A) in % (2) →
Admissible continuous application
of current in A with 100 %
DC
(3) →
– Version "G24...-8"
Admissible working range against the ambient temperature
Limited valve performance
Notice!
The characteristic curves have been determined for coils with
valve with medium test block size (80 x 80 x 80 mm), without
flow in calm air.
Depending on the installation conditions (block size, flow, air
circulation, etc.) there may be a better heat dissipation. Thus,
the area of application is broadened.
In single cases, more unfavorable conditions may lead to limi-
tations of the area of application.
6
2
1
50
88
6
18,8
21
0
LS
5
15
1
4
84
64,4
32
55
98
12/14 Bosch Rexroth AG Hydraulics
KBPS RE 18139-05/07.12
Unit dimensions (dimensions in mm)
1 Mating connector for connector "K4"
(separate order, see data sheet 08006)
2 Mating connector for connector "C4"
(separate order, see data sheet 08006)
3 Mating connector for connector "K40"
(separate order, see data sheet 08006)
4 Space required to remove the ma ting connec tor
5 Hexagon SW22 for screwing in the
pole tube; tightening torque M
A
= 40
+6
Nm
6 Solenoid nut, tightening torque M
A
= 5
+1
Nm
1
= main port 1
2
= main port 2
LS = Location Shoulder
Ø9,5±0,1
Ø11,1
+0,05
A-B
Ø0,2
A-B
Ø0,05
B
Rzmax 8
Ø14,48
+0,1
A-B
Ø0,05
min 10
13,5±0,1
19,05
+0,1
0
LS
Rzmax 8
M16 x 1,56H
Ø16,65
+0,05
A
Rz 16
Ø17,86
+0,05
A-B
Ø0,05
min Ø32
1)
0,8
+0,8
3,6±0,1
11,1
±0,1
max Ø4,8
2
1
45°
+0,25
Y
X
X
Rz 16
Rz 16
A-B
0,05
30º
2)
A-B
Ø0,05
Ø17,15
+0,05
Y
Ø11,9
+0,1
R0,8
2)
Rz 16
25º
2)
75º
A-B
Ø0,05
-0,2 +0,2
Rz 32
3)
A-B
Ø0,05
Hydraulics Bosch Rexroth AG
RE 18139-05/07.12 KBPS
13/14
Mounting cavity R/T-8A; 2 main ports; thread M16 x 1.5-6H (dimensions in mm)
1)
With counterbore, deviating from T-8A
2)
All seal ring insertion faces are rounded and free of burrs
3)
Deviating from T-8A
Tolerance for all angles ±0.5°
1
= main port 1
2
= main port 2
LS = Location Shoulder
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 informa-
tion set forth in it, are the exclusive property of Bosch Rexroth AG. It
may not be reproduced or given to third parties without its consent.
The data specified above only serve to describe the product. No state-
ments concerning a certain condition or suitability for a certain applica-
tion 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.
14/14 Bosch Rexroth AG Hydraulics
KBPS RE 18139-05/07.12
Available individual components
1)
Notice!
After exchange of the solenoid coil, the pressure set in the
factory may change by ±5 %.
Item Denomination Direct voltage Material no.
020 Coil for individual connection
1)
Version "K4" 12 V
24 V
24 V / 800 mA
R901002932
R901002319
R901049962
Version "K40" 12 V
24 V
24 V / 800 mA
R901003055
R901003053
R901050010
Version "C4" 12 V
24 V
24 V / 800 mA
R901003044
R901003026
R901049963
050 Nut R900992146
090 Seal ring for pole tube R900007769
998 Seal kit of the valve R961000376
999
020
090
050
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 informa-
tion set forth in it, are the exclusive property of Bosch Rexroth AG. It
may not be reproduced or given to third parties without its consent.
The data specified above only serve to describe the product. No state-
ments concerning a certain condition or suitability for a certain applica-
tion 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.
Hydraulics Bosch Rexroth AG
RE 18139-05/07.12 KBPS
15/14
Notes
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 informa-
tion set forth in it, are the exclusive property of Bosch Rexroth AG. It
may not be reproduced or given to third parties without its consent.
The data specified above only serve to describe the product. No state-
ments concerning a certain condition or suitability for a certain applica-
tion 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.
16/14 Bosch Rexroth AG Hydraulics
KBPS RE 18139-05/07.12
Notes
