DBW 20 BG2-5X/50U6EG125N9K4V/12
Manufacturer: Bosch Rexroth
Material #: R978916235
Model : DBW 20 BG2-5X/50U6EG125N9K4V/12
***Disclaimer: The following summary contains information gathered from various sources such as product descriptions, technical specifications and catalogs. While efforts have been made to provide accurate details, inaccuracies may occur. It is advised to verify all information by contacting Bosch Rexroth directly.***
The Bosch Rexroth DBW 20 BG2-5X/50U6EG125N9K4V/12 (R978916235) is a sophisticated pressure relief valve designed for advanced hydraulic applications. This valve is pilot-operated, ensuring precise control over the limiting and solenoid-actuated unloading of operating pressure. It features a main valve with a spool insert and a pilot control valve that includes a pressure adjustment element and an integrated directional spool valve. The DBW series stands out for its capability to delay the opening from port B to B through a switching shock damping valve, effectively minimizing pressure peaks and reducing acoustic decompression shocks in the return line.
This particular model is engineered for subplate mounting with porting patterns conforming to ISO NG6, NG10, and NG16 standards. It can also be utilized as a screw-in cartridge valve, providing versatility in installation methods. Users have several options for adjusting pressure settings, including a rotary knob, sleeve with hexagon and protective cap, lockable rotary knob with scale, or rotary knob with scale.
The DBW 20 BG2-5X/50U6EG125N9K4V/12 offers high-power solenoid operation for unloading via either a built-on directional spool valve or directional poppet valve. Optional switching shock damping enhances its performance in various hydraulic systems. With its robust design, this model can withstand maximum operating pressures up to 350 bar and handle maximum flow rates up to 50 l/min.
Its size and component series X indicate its suitability for demanding applications where reliable pressure relief is critical. The recommended nozzle size ordering code R ensures optimal decompression shock damping tailored to specific system requirements. This product exemplifies Bosch Rexroth's commitment to engineering excellence in hydraulic components.
$1,472.00 USD
More are expected on May 16, 2025
Status: This product is temporarily out of stock.
Qty: Delivered as early as May 16, 2025 when ordered in
This product is eligible for factory repair.
The pressure valve type DBW is a pilot-operated pressure relief valve.
They are used for limiting and solenoid-actuated unloading the operating pressure.
The valve basically consists of the main valve (1) with main spool insert (3) and pilot control valve (2) with pressure adjustment element and one integrated directional spool valve (16).
The function of this valve is basically the same as that of valve type DB. The unloading of the main spool (3) is, however, achieved by controlling the mounted directional spool valve (16).
Pressure relief valve with switching shock damping (sandwich plate), version "DBW.../..S6...R12"
The opening of the connection from B2 to B1 is delayed by means of the switching shock damping valve (17). Pressure peaks and acoustic decompression shocks in the return line are thus avoided. It is installed between the pilot control valve (2) and the directional valve (16).
The degree of damping (decompression shock) is determined by the size of the nozzle (18). Nozzle Ø1.2 mm (ordering code "R12") is recommended.
|
01 |
02 |
03 |
04 |
05 |
06 |
07 |
08 |
09 |
10 |
11 |
12 |
13 |
14 |
15 |
16 |
17 |
18 |
19 |
20 |
21 |
22 |
|
|
DB |
W |
5X |
/ |
K4 |
* |
|
01 |
Pressure relief valve |
DB |
|
02 |
With attached directional valve |
W |
|
03 |
Pilot-operated valve (complete) |
no code |
|
Pilot control valve without main spool insert (do not enter any size) |
C |
|
|
Pilot control valve with main spool insert (enter size 10 or 30) |
C |
|
|
Pilot control valve without main spool insert for subplate mounting (do not enter any size) |
T 1) |
|
|
04 |
Size 10 |
|
|
Subplate mounting "no code" |
10 |
|
|
Threaded connection "G" |
10 (G1/2) |
|
|
Size 16 |
||
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Threaded connection "G" |
15 (G3/4) |
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|
Size 25 |
||
|
Subplate mounting "no code" |
20 |
|
|
Threaded connection "G" |
20 (G1) |
|
|
Threaded connection "G" |
25 (G1 1/4) |
|
|
Size 32 |
||
|
Subplate mounting "no code" |
30 |
|
|
Threaded connection "G" |
30 (G1 1/2) |
|
|
05 |
Normally closed |
A |
|
Normally open |
B |
|
|
Type of connection |
||
|
06 |
Subplate mounting or cartridge valve |
no code |
|
For threaded connection |
G |
|
|
Adjustment type for pressure adjustment |
||
|
07 |
Rotary knob (not for version "C" and "T") |
1 |
|
Sleeve with hexagon and protective cap |
2 |
|
|
Lockable rotary knob with scale |
3 2) |
|
|
Rotary knob with scale |
7 |
|
|
08 |
Main spool Ø24 mm (all sizes) |
– |
|
Main spool Ø28 mm (only for NG32) |
N |
|
|
09 |
Component series 50 … 59 (50 … 59: unchanged installation and connection dimensions) |
5X |
|
10 |
Set pressure up to 50 bar |
50 |
|
Set pressure up to 100 bar |
100 |
|
|
Set pressure up to 200 bar |
200 |
|
|
Set pressure up to 315 bar |
315 |
|
|
Set pressure up to 350 bar |
350 |
|
|
Pilot oil flow |
||
|
11 |
External pilot oil supply, internal pilot oil return |
X 3) |
|
Internal pilot oil supply, external pilot oil return |
Y |
|
|
Pilot oil supply and pilot oil return external |
XY 3) |
|
|
12 |
Standard version |
no code |
|
Valve for minimum cracking pressure (not for versions "without main spool insert" and not suitable for mutual relief) |
U 4) |
|
|
13 |
Without switching shock damping |
no code |
|
With switching shock damping |
S |
|
|
14 |
With directional spool valve (data sheet 23178) |
6E |
|
With directional seat valve (data sheet 22058) |
6SM |
|
|
15 |
Direct voltage 24 V |
G24 |
|
Alternating voltage 230 V, 50/60 Hz |
W230 |
|
|
16 |
Without manual override |
no code |
|
With concealed manual override |
N9 |
|
|
With manual override |
N |
|
|
Electrical connection |
||
|
17 |
Connector DIN EN 175301-803 |
K4 5) |
|
18 |
Nozzle Ø1,2 mm in channel B of the directional spool valve (version "6E") |
R12 6) |
|
Nozzle Ø1,2 mm in channel P of the directional seat valve (version "6SM") |
B12 6) |
|
|
Corrosion resistance |
||
|
19 |
None |
no code |
|
Seal material |
||
|
20 |
NBR seals |
no code |
|
FKM seals |
V |
|
|
Observe compatibility of seals with hydraulic fluid used. (Other seals upon request) |
||
|
Equipment Directive |
||
|
21 |
Without type-examination procedure |
no code |
|
Type-examination tested safety valve according to Pressure Equipment Directive 2014/68/EU |
E |
|
|
22 |
Further details in the plain text |
* |
| 1) | DBT corresponds to DBC, however with closed central bore |
| 2) | H-Key with material no. R900008158 is included in the scope of delivery. |
| 3) | Not with version "DBC" |
| 4) | Only possible up to pressure rating 315 bar |
| 5) | Mating connectors, separate order, see "Accessories" |
| 6) | Ordering code only necessary with version with attached directional valve and switching shock damping ("S") |
Type-examination tested safety valves type DBW…E
(Component series 5X according to Pressure Equipment Directive 2014/68/EU)
|
NG |
Type designation |
Component marking |
Maximum flow qVmax in l/min with pilot oil return |
Set response overpressurep in bar |
|
|
external "Y" |
internal "–" |
||||
|
10 |
|
TÜV.SV.▢ – 851.12.F.G.p |
170 230 230 230 |
130 200 200 200 |
30 ... 60 61 ... 110 111 ... 210 211 ... 350 |
|
25 |
|
TÜV.SV.▢ – 852.22.F.G.p |
250 270 420 450 |
180 210 320 400 |
30 ... 60 61 ... 110 111 ... 210 211 ... 350 |
|
32 |
|
TÜV.SV.▢ – 853.32.F.G.p |
600 600 650 700 |
225 340 540 580 |
30 ... 60 61 ... 110 111 ... 210 211 ... 350 |
|
1 |
Directional valve, normally closed |
A |
|
Directional valve, normally open |
B |
|
|
2 |
For subplate mounting |
no code |
|
For threaded connection |
G |
|
|
Adjustment type for pressure adjustment |
||
|
3 |
Hand wheel (pressure adjustment sealed, unloading or setting of a lower response pressure possible!) |
1 |
|
With sealed protective cap (no adjustment/unloading possible) |
2 |
|
|
Pressure |
||
|
4 |
To be entered by the customer, e.g. pressure adjustment ≥ 30 bar and possible in 5 bar steps. |
e.g. 150 |
|
Pilot oil flow |
||
|
5 |
Pilot oil supply internal, pilot oil return internal |
no code |
|
Pilot oil supply internal, pilot oil return external (Recommendation) |
Y 1) |
|
|
Electrical specifications |
||
|
6 |
see Type code above |
e.g. EG24N9K4 |
|
7 |
NBR seals |
no code |
|
FKM seals |
V |
|
|
▢ |
Value entered at the factory |
|
| 1) | Pilot oil supply external "X" not possible |
(measured with HLP46, ϑOil = 40 ±5 °C)
Standard version
Minimum set pressure and circulation pressure dependent on the flow 1)
| 1) | The characteristic curves apply to an output pressure pT =0 bar in the entire flow range. |
Version “U”
Minimum set pressure and circulation pressure dependent on the flow 1)
Inlet pressure dependent on the flow
Notice:
The characteristic curves were measured with external, depressurized pilot oil return.
Due to the internal pilot oil return, the inlet pressure increases by the output pressure present in port T.
Pilot flow
Type-examination tested safety valves
(Component series 5X, according to Pressure Equipment Directive 2014/68/EU)
Counter pressure in the discharge line
Basically, the valve should be operated without counter pressure in the discharge line, if possible. With counter pressure in the discharge line, the maximum flow possible is reduced. There is a relation between the maximum counter pressure pT in the discharge line and flow qV, which can be seen from the following characteristic curves. Characteristic curves for intermediate values of the response pressure which are not listed must be determined by means of interpolation.
With a flow approaching zero, the maximum counter pressure pT is in each case 10 % of the response pressure. With increasing flow, the maximum counter pressure pT is reduced.
Interpolation of intermediate values from the diagram
At the pT axis, mark 1/10 of the value of pA. Determine the next lower and the next higher characteristic curve for this point. The point marked at pT divides the section between lower and higher characteristic curve on the pT axis with a certain percentage. At the qVmax axis, divide the section between next lower and next higher characteristic curve in the same percentage as the section at the pT axis. From the zerocrossing on the qVmax axis determined in that way, draw a straight line to the value on the pT axis marked before. Mark the system flow to be secured at the qVmax axis. Read off the maximum counter pressure for this value using the line at the pT axis drawn before.
Determination of the maximum counter pressure
Example 1 (with already existing characteristic curve):
Flow of the system / accumulator to be secured:qVmax = [si]300 l/min[/si][imp]79.3 USgpm[/imp Safety valve set to: pA = [si]80 bar[/si][imp]1150 psi[/imp]. Read off the maximum counter pressure pT of approx. [si]12 bar[/si][imp]175 psi[/imp] from the diagram (see arrows, dashed line " ").
Example 2 (with interpolated characteristic curve):
Flow of the system / accumulator to be secured: qVmax = [si]300 l/min[/si][imp]79.3 USgpm[/imp Safety valve set to: pA = [si]80 bar[/si][imp]1150 psi[/imp] Value to be marked at the axis referred to as pT: 1/10 x [si]80 bar[/si][imp]1150 psi[/imp] = [si]8 bar[/si][imp]115 psi[/imp]. Read off the maximum counter pressure pT of approx. [si]1 bar[/si][imp]15 psi[/imp] from the diagram (see arrows, dashed/dotted line " ").
Size 10
Diagram for determining the maximum counter pressure pT in the discharge line at port T of the valve dependent on the flow qVmax for valves type DB(W)...E with different response pressures pA.Intermediate values may be determined by means of interpolation. Regarding the procedure for interpolation refer to "Interpolation of intermediate values from the diagram".
Size 20
Diagram for determining the maximum counter pressure pT in the discharge line at port T of the valve dependent on the flow qVmax for valves type DB(W)...E with different response pressures pA.Intermediate values may be determined by means of interpolation. Regarding the procedure for interpolation refer to "Interpolation of intermediate values from the diagram".
Size 30
Diagram for determining the maximum counter pressure pT in the discharge line at port T of the valve dependent on the flow qVmax for valves type DB(W)...E with different response pressures pA.Intermediate values may be determined by means of interpolation. Regarding the procedure for interpolation refer to "Interpolation of intermediate values from the diagram".
|
pA |
Response pressure in bar |
|
pT |
Maximum counter pressure in the discharge line (port T) in bar (sum of all possible counter pressures; also see AD2000 data sheet - A2) |
|
pT max |
10% x pA (with qV=0 l/min) according to Pressure Equipment Directive 2014/68/EU |
|
qV max |
Maximum flow in l/min |
Type DBW…S6E...R12
Threaded connection "G"
Dimensions in mm
|
1 |
Name plate |
|
2 |
X port for pilot oil supply, external |
|
3 |
Y port for pilot oil return, external |
|
4 |
Adjustment type "1" |
|
5 |
Adjustment type "2" |
|
6 |
Adjustment type "3" |
|
7 |
Adjustment type "7" |
|
8 |
Hexagon SW10 |
|
9 |
Space required to remove the key |
|
11 |
Valve mounting bores |
|
19 |
Omitted with internal pilot oil return |
|
Version |
D1 |
ØD2 |
T1 |
|
mm |
mm |
||
| "DB 10 G" | G1/2 | 34 | 14 |
| "DB 15 G" | G3/4 | 42 | 16 |
| "DB 20 G" | G1 | 47 | 18 |
| "DB 25 G" | G1 1/4 | 58 | 20 |
| "DB 30 G" | G1 1/2 | 65 | 22 |
Dimensions for attached directional valve see "Subplate mounting"
Subplate mounting with directional spool valve "6E"
|
1 |
Name plate |
|
2 |
X port for pilot oil supply, external |
|
3 |
Y port for pilot oil return, external |
|
4 |
Adjustment type "1" |
|
5 |
Adjustment type "2" |
|
6 |
Adjustment type "3" |
|
7 |
Adjustment type "7" |
|
8 |
Hexagon SW10 |
|
9 |
Space required to remove the key |
|
10 |
Locking pin |
|
11 |
Valve mounting bores |
|
12.1 |
Directional spool valve NG6 |
|
13 |
Solenoid “a” |
|
14 |
Dimension for valve without manual override |
|
15 |
Mating connector without circuitry (separate order) |
|
16 |
Mating connector with circuitry (separate order) |
|
17 |
Switching shock damping valve, optional |
|
18 |
Space required to remove the mating connector |
|
19 |
Omitted with internal pilot oil return |
|
30 |
Dimension for solenoid with manual override “N” |
|
31 |
Dimension ( ) for valve with AC solenoid |
|
32 |
Dimension for valve with DC solenoid |
|
33 |
Space required to remove the solenoid coil |
|
34 |
Dimension for valve with concealed manual override "N9" |
|
35 |
Lock nut SW17, tightening torque MA = 10+5 Nm |
|
Version |
L1 |
L2 |
L3 |
L4 |
L5 |
L6 |
L7 |
L8 |
L9 |
B1 |
B2 |
ØD1 |
|
mm |
mm |
mm |
mm |
mm |
mm |
mm |
mm |
mm |
mm |
mm |
mm |
|
| "DB 10" | 91 | 53.8 | 22.1 | 27.5 | 22.1 | 47.5 | 0 | 25.5 | 2 | 78 | 53.8 | 14 |
| "DB 20" | 116 | 66.7 | 33.4 | 33.3 | 11.1 | 55.6 | 23.8 | 22.8 | 10.5 | 100 | 70 | 18 |
| "DB 30" | 147.5 | 88.9 | 44.5 | 41 | 12.7 | 76.2 | 31.8 | 20 | 21 | 115 | 82.6 | 20 |
Subplate mounting with directional seat valve "6SM"
|
1 |
Name plate |
|
2 |
X port for pilot oil supply, external |
|
3 |
Y port for pilot oil return, external |
|
4 |
Adjustment type "1" |
|
5 |
Adjustment type "2" |
|
6 |
Adjustment type "3" |
|
7 |
Adjustment type "7" |
|
8 |
Hexagon SW10 |
|
9 |
Space required to remove the key |
|
10 |
Locking pin |
|
11 |
Valve mounting bores |
|
12.2 |
Directional seat valve NG6 |
|
13 |
Solenoid “a” |
|
14 |
Dimension for valve without manual override |
|
15 |
Mating connector without circuitry (separate order) |
|
16 |
Mating connector with circuitry (separate order) |
|
17 |
Switching shock damping valve, optional |
|
18 |
Space required to remove the mating connector |
|
19 |
Omitted with internal pilot oil return |
|
30 |
Dimension for solenoid with manual override “N” |
|
31 |
Dimension ( ) for valve with AC solenoid |
|
32 |
Dimension for valve with DC solenoid |
|
33 |
Space required to remove the solenoid coil |
|
34 |
Dimension for valve with concealed manual override "N9" |
|
35 |
Lock nut SW17, tightening torque MA = 10+5 Nm |
Pilot control valve with ("DBWC 10 or 30") or without main spool insert ("DBWC, DBWT")
Dimensions in mm
Dimensions for attached directional valve see "Subplate mounting"
Installation bore
Dimensions in mm
|
1 |
Name plate |
|
3 |
Y port for pilot oil return, external |
|
5 |
Adjustment type "2" |
|
6 |
Adjustment type "3" |
|
7 |
Adjustment type "7" |
|
8 |
Hexagon SW10 |
|
9 |
Space required to remove the key |
|
11 |
Valve mounting bores |
|
20 |
Seal ring |
|
21 |
Main spool insert |
|
22 |
Bore Ø32 mm can cut Ø45 mm at any point. However, it must be observed that the connection bore X and the mounting bore are not damaged! |
|
23 |
Support ring and seal ring are to be inserted into this bore before assembly of the main spool. |
|
24 |
Nozzle (separate order; recommended nozzle Ø1.0 mm) |
|
25 |
Seal ring |
|
26 |
Seal ring |
|
27 |
Seal ring |
|
28 |
Support ring |
|
29 |
Support ring |
|
35 |
Lock nut SW17, tightening torque MA = 10+5 Nm |
Valve mounting screws (separate order)
For reasons of stability, exclusively the following valve mounting screws may be used:
Version "DB 10"4 x ISO 4762 - M12 x 50 - 10.9-flZn/nc/480h/C
with friction coefficient μtotal = 0.09 … 0.14
tightening torque MA = 75 Nm ±10%
material no. R913015611 Version "DB 20"
4 x ISO 4762 - M16 x 50 - 10.9-flZn/nc/480h/C
with friction coefficient μtotal = 0.09 … 0.14
tightening torque MA = 185 Nm ±10%
material no. R913015664 Version "DB 30"
4 x DIN 912 - M18 x 50 - 10.9-flZn/nc/480h/C
with friction coefficient μtotal = 0.09 … 0.14
tightening torque MA = 248 Nm ±10%
material no. R913015903 Version "DBC", "DBC 10", "DBC 30" and "DBT"
4 x ISO 4762 - M8 x 40 - 10.9-flZn/nc/480h/C
with friction coefficient μtotal = 0.09 … 0.14
tightening torque MA = 31 Nm ±10%
material no. R913015798
Notice:
The tightening torques stated are guidelines when using screws with the specified friction coefficients and when using a manual torque wrench (tolerance ±10%).
|
|
Required surface quality of the valve contact surface |
Mating connectors for valves with connector “K4”, without circuitry, standard
3P Z4
Mating connectors for valves with connector “K4”, without circuitry, standard
3P Z4
For valves with connector “K4” according to EN 175301-803 and ISO 4400, 2-pole + PE, “large cubic connector” Mating connectors for valves with one or two solenoids (individual connection)Data sheet
Spare parts & repair
Mating connectors for valves with connector “K4”, without circuitry, standard
3P Z45
Mating connectors for valves with connector “K4”, without circuitry, standard
3P Z45
For valves with connector “K4” according to EN 175301-803 and ISO 4400, 2-pole + PE, “large cubic connector” Mating connectors for valves with one or two solenoids (individual connection)Data sheet
Spare parts & repair
Mating connectors for valves with connector “K4”, with indicator light
3P Z5L
Mating connectors for valves with connector “K4”, with indicator light
3P Z5L
For valves with connector “K4” according to EN 175301-803 and ISO 4400, 2-pole + PE, “large cubic connector” Mating connectors for valves with one or two solenoids (individual connection)Data sheet
Spare parts & repair
Mating connectors for valves with connector “K4”, with indicator light and Zener diode suppression circuit
3P Z5L1
Mating connectors for valves with connector “K4”, with indicator light and Zener diode suppression circuit
3P Z5L1
For valves with connector “K4” according to EN 175301-803 and ISO 4400, 2-pole + PE, “large cubic connector” Mating connectors for valves with one or two solenoids (individual connection)Data sheet
Spare parts & repair
Mating connectors for valves with connector “K4”, with rectifier
3P RZ5
Mating connectors for valves with connector “K4”, with rectifier
3P RZ5
For valves with connector “K4” according to EN 175301-803 and ISO 4400, 2-pole + PE, “large cubic connector” Mating connectors for valves with one or two solenoids (individual connection)Data sheet
Spare parts & repair
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