1/14
Information on available spare parts:
www.boschrexroth.com/spc
Proportional pressure relief
valve, direct operated,
increasing characteristic curve
Type KBPS.8A (High Performance)
Component size 8
Component series A
Maximum operating pressure 420 bar
Maximum flow 2 l/min
RE 18139-04/06.12
Replaces: 11.11
Table of contents Features
– 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
– In case of power failure, minimum set pressure
– Control electronics: Data sheet
• Plug-in proportional amplifier
type VT-SSPA1…
30116
• Analog amplifier type RA… 95230
• BODAS controller type RC… 95200
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
2/14 Bosch Rexroth AG Hydraulics KBPS RE 18139-04/06.12
Ordering code
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
Minimum pressure with command value = 0 = A
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 connector 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 A A H C V
*
1)
Mating connectors, separate order, see data sheet 08006.
Preferred types
Type Material number
KBPSC8AA/HCG24K4V R901049804
KBPSF8AA/HCG24K4V R901049817
KBPSL8AA/HCG24K4V R901027408
KBPSN8AA/HCG24K4V R901049877
KBPSP8AA/HCG24K4V R901047007
KBPSR8AA/HCG24K4V R901049860
KBPST8AA/HCG24K40V R901045871
KBPSL8AA/HCG24K4V-8 R901053398
KBPSP8AA/HCG24C4V-8 R901132980
KBPSR8AA/HCG24C4V-8 R901128882
2
1
4
3
5
6
(T)
(P)
2
1
Hydraulics Bosch Rexroth AGRE 18139-04/06.12 KBPS 3/14
Function, section, symbol
Symbol
General
Valves of type KBPS.8A 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 pule 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 mini-
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
For the setting of the system pressure, a command value is
specified at the control electronics. Depending on the com-
mand value, the electronics necessary for operation actuate
the solenoid with electric current. The proportional solenoid
converts the electric current into mechanical force that acts
on the valve poppet (6) via the armature plunger. The valve
poppet (6) pushes onto the valve seat (5) and blocks the con-
nection between main port ① and ②. If the hydraulic force on
the valve poppet (6) corresponds to the solenoid force, the
valve controls the set pressure by lifting the valve poppet (6)
off the valve seat (5) and thus enabling hydraulic fluid flow
from main port ① to ②. If the command value is zero, the
minimum 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 18139-04/06.12
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 direction
(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 0 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 hydrau-
lic fluid - cleanliness class according to ISO 4406 (c)
Class 20/18/15
3)
1)
Attention!
The maximum operating pressure is the total of
set pressure and return flow
pressure!
2)
If the valve is installed in a mounting cavity made of non-
magnetically conductive material, the maximum set pressure
is < 3 % lowe r.
Attention!
The
valves are set in the factory. In case of sub-
sequent adjustment, the warranty will become invalid!
3)
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 AGRE 18139-04/06.12 KBPS 5/14
Technical data (For applications outside these parameters, please consult us!)
hydraulic
Hysteresis
4)
< 5 % of the max. set pressure
Range of inversion
4)
< 0.5 % of the max. set pressure
Response sensitivity
4)
< 0.5 % of the max. set pressure
Manufacturing tolerance of
the command value pres-
sure characteristic curve
– Command value 100 % < 5 % of the max. set pressure
– Command value 0 < 2 % of the max. set pressure
Step response (T
u
+ T
g
) 0 → 100 % and/or 100 % → 0 ms 70 (depending on the system)
Hydraulic fluid Classification Suitable
sealing materials
Standards
Mineral oils and related hydrocarbons HL, HLP, HLPD, HVLP, HVLPD FKM DIN 51524
Environmentally compatible
– Insoluble in water
HEES FKM
ISO 15380
HEPR FKM
– Soluble in water HEPG FKM ISO 15380
Flame-resistant
– Water-free HFDU, HFDR FKM ISO 12922
– Water-containing HFAS FKM ISO 12922
Important information on hydraulic fluids!
– For more information and data on the use of other hydrau-
lic fluids refer to data sheet 90220 or contact us!
– There may be limitations regarding the technical valve
data (temperature, pressure range, service life, mainte-
nance intervals, etc.)!
– The flash point of the process and operating medium used
must be 40 K higher than the maximum solenoid sur-
face temperature.
– Flame-resistant - containing water: Maximum pressure
differential per control edge 175 bar, otherwise, increased
cavitation erosion!
Tank pre-loading < 1 bar or > 20 % of the pressure differ-
ential. The pressure peaks should not exceed the maxi-
mum operating pressures!
– Environmentally compatible: When using environ-
mentally compatible hydraulic fluids that are simultane-
ously zinc-solving, zinc may accumulate in the medium
(700 mg zinc per pole tube).
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
5)
Maximum coil temperature
6)
°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 controller type RC…, see data sheet 95200
Design according to VDE 0580
4)
Measured with analog amplifier type RA2-1/10, see data
sheet 95230
5)
In case of use more than 2000 m a.s.l., please consult us.
6)
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.
250
200
150
50
25 50 75 100
100
0
0 0,4 0,8 1,2 1,6 2,0
10
60
30
50
20
40
0 0,4 0,8 1,2 1,6 2,0
200
100
150
50
175
125
25
75
0 0,4 0,8 1,2 1,6 2,0
20
140
60
100
40
80
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
10
40
30
20
6/14 Bosch Rexroth AG Hydraulics KBPS RE 18139-04/06.12
Characteristic curves (measured with HLP46, ϑ
Oil
= 40 °C ± 5 °C and 24 V coil)
Command value in % →
Pressure in the 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 50 bar
Pressure in main port ① in bar →
Flow in l/min →
Pressure rating 150 bar
Pressure in the 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 100 bar
Command value in % →
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 30 bar
Pressure in main port ① in bar →
0 0,4 0,8 1,2 1,6 2,0
50
350
150
250
100
200
300
0 0,4 0,8 1,2 1,6 2,0
50
450
250
350
150
300
400
100
200
0 0,4 0,8 1,2 1,6 2,0
50
450
250
350
150
300
400
100
200
0 0,4 0,8 1,2 1,6 2,0
100
600
300
500
200
400
0 0,4 0,8 1,2 1,6 2,0
40
280
120
200
80
160
240
Hydraulics Bosch Rexroth AGRE 18139-04/06.12 KBPS 7/14
Characteristic curves (measures 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
Flow in l/min
→
Pressure rating 420 bar
Pressure in the main port ① depending on the flow.
(The characteristic curve was measure without coun ter pressure in main port ②.)
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 →
Flow in l/min →
Pressure rating 210 bar
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
2
8
20
4
10
14
16
6
12
18
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
2
8
20
4
10
14
16
6
12
18
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
2
8
20
4
10
14
16
6
12
18
8/14 Bosch Rexroth AG Hydraulics KBPS RE 18139-04/06.12
Flow in l/min →
Pressure rating 150 bar
Minimum set pressure in bar →
Flow in l/min →
Pressure rating 210 bar
Minimum set pressure in bar →
Flow in l/min →
Pressure rating 250 bar
Minimum set pressure in bar →
Minimum set pressure in main port ① with command value 0.
(The characteristic curve was measure without coun ter pressure in main port ②.)
Flow in l/min
→
Pressure rating 30 bar
Minimum set pressure in bar →
Flow in l/min →
Pressure rating 100 bar
Minimum set pressure in bar →
Flow in l/min →
Pressure rating 50 bar
Minimum set pressure in bar →
Characteristic curves (measured with HLP46, ϑ
Oil
= 40 °C ± 5 °C and 24 V coil)
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
2
8
20
4
10
14
16
6
12
18
0 0,4 0,8 1,2 1,6 2,0
2
8
20
4
10
14
16
6
12
18
Hydraulics Bosch Rexroth AGRE 18139-04/06.12 KBPS 9/14
Flow in l/min →
Pressure rating 315 bar
Minimum set pressure in bar →
Flow in l/min →
Pressure rating 350 bar
Minimum set pressure in bar →
Flow in l/min →
Pressure rating 420 bar
Minimum set pressure in bar →
Minimum set pressure in main port ① with command value 0.
(The characteristic curve was measure without coun ter pressure in main port ②.)
Characteristic curves (measured with HLP46, ϑ
Oil
= 40 °C ± 5 °C and 24 V coil)
-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 18139-04/06.12
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 DC
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 AGRE 18139-04/06.12 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
(1.76 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.
5
6
2
1
50
88
6
18,8
21
0
LS
15
1
4
84
64,4
32
55
98
Ø12,9
Ø37
Ø30
12/14 Bosch Rexroth AG Hydraulics KBPS RE 18139-04/06.12
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
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
A-B
Ø0,05
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 AGRE 18139-04/06.12 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 18139-04/06.12
Available individual components
999
020
090
050
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
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 AGRE 18139-04/06.12 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 18139-04/06.12
Notes
