Inverse Proportional Pressure-Relief Cart., Size 2…4
Q
max
= 24 l/min,p
max
= 350bar
Direct acting, electrically operated
Series DBDRB-1LG…
1/6
Reference: 400-P-585201-EN-03
Issue: 03.2017
S Compact construction
for cavity type AL– 3/4-16 UNF
S Operated by a proportional solenoid
S Nominal pressure when solenoid de-energised
(fail-safe function)
S 6 pressure ranges available
S All exposed parts, without solenoid coil,
with zinc-nickel plating
S High pressure wet-armature solenoids
S The slip-on coil can be rotated, and it can be
replaced without opening the hydraulic envelope
S With integral manual pressure setting
S Can be fitted in a line-mounting body
1 Description
Series DBDRB-1LG… inverse proportional pressure-relief
valves are direct acting screw-in cartridges of sliding-spool
design with a falling pressure/current characteristic and a
3/4-16 UNF mounting thread. With these pressure-relief
cartridges, the relief pressure is dependent on the electrical
control signal and can be continuously varied. When the so
lenoid is de-energised (initial position), the relief pressure is
the nominal pressure of the applicable spring range (fail-
safe function). Any pressure at port 1 is additive to the valve
setting at port 2, therefore port 1 should preferably be con
nected directly to tank. In control mode, the relief pressure
is inversely proportional to the change in the required value
(amplifier output current). In order to obtain precise pres
sure settings over the whole of the required pressure range
(optimum resolution), the pressure relief cartridges are avai
lable in six spring ranges. If a proportional solenoid is faulty,
for example, the integral manual pressure setting enables
the required pressure to be set mechanically. Inverse pro
portional pressure-relief cartridges are predominantly used
in mobile and industrial applications to allow a pressure in
hydraulic installations to be limited electro-proportionally.
All external parts of the cartridge are zinc-nickel plated to
DIN 50979 – solenoid coil are zinc plated, and are thus suit
able for use in the harshest operating environments. The
slip-on coils can be replaced without opening the hydraulic
envelope and can be positioned at any angle through 360°.
If you intend to manufacture your own cavities or are desi
gning a line-mounting installation, please refer to the sec
tion “Related data sheets”.
2 Symbol
1
2
3 Technical data
General characteristics Description, value, unit
Designation inverse proportional pressure-relief cartridge
Design direct acting, electrically operated
Mounting method screw-in cartridge 3/4-16UNF
Tightening torque 40 Nm ± 10%
Size nominal size 2...4, cavity type AL
Weight 0.54 kg
400-P-585201-EN-03/03.2017
Series DBDRB-1LG…
2/6
Description, value, unitGeneral characteristics
Mounting attitude unrestricted (preferably vertical, coil down)
Ambient temperature range -25°C … +50°C
Hydraulic characteristics Description, value, unit
Maximum operating pressure (p
max
) - main port 2
- port 1
350bar
250 bar
1)
Maximum flow rate 24l/min
Nominal pressure ranges (p
N
) …25bar, …63bar, …100bar,
…160bar, …230bar, …350bar
Leakage flow rate 2 1 … 0.10l/min = pressure range 25 bar / 63bar
… 0.20l/min = pressure range 100 bar
… 0.25l/min = pressure range 160bar
… 0.30l/min = pressure range 230bar
… 0.40l/min = pressure range 350bar
Flow direction 2 1 see symbols
Hydraulic fluid HL and HLP mineral oil to DIN 51 524;
for other fluids, please contact BUCHER
Hydraulic fluid temperature range -25°C … +70°C
Viscosity range 15…380mm
2
/s (cSt), recommended 20...130mm
2
/s (cSt)
Minimum fluid cleanliness
Cleanliness class to ISO 4406:1999
class 18/16/13
ATTENTION!
1)
To prevent any pressure surges, port 1 must be routed to tank with the least possible back-pressure. Any tank
pressure acting at port 1 is additive to the pressure setting at the main port 2.
Electrical characteristics Description, value, unit
Supply voltage 12V DC, 24V DC
Control current 12 V = 0…1600 mA, 24 V = 0…800 mA
Power consumption at max. control current max. 19.5 W
Coil resistance R - cold value at 20°C
- max. warm value
12 V = 4.8/24V = 17.7
12 V = 7.5/24V = 30
Recommended PWM frequency (dither) 200 Hz
Hysteresis with PWM 2…4 % I
N
Reversal error with PWM 2…4 % I
N
Sensitivity with PWM < 1 % I
N
Reproducibility with PWM < 2 % p
N
Switching time 6 … 90 ms (Solenoid ON)
6 … 20 ms (Solenoid OFF)
These times are strongly influenced by fluid pressure, flow rate and viscosity, as well as by
the dwell time under pressure.
Relative duty cycle 100%
Protection class to ISO20653 / EN60529 IP 65
Electrical connection 3-pin square plug to ISO 4400 / DIN 43 650 (standard)
for other connectors, see “Ordering code”
400-P-585201-EN-03/03.2017
Series DBDRB-1LG…
3/6
4 Performance graphs measured with oil viscosity 33mm
2
/s (cSt)
p = f (I) Pressure adjustment characteristic (Q=1l/min)
P0134.ai
0
40
30
70
60
50
20
10
I [mA]0 200
400
400
800
500
1000
600
1200
700
1400
800
1600
100
200
300
600
p
2
[bar]
p
N
63 barp
N
63 bar
p
N
25 barp
N
25 bar
p = f (Q) Pressure - Flow rate characteristic p
N
= 25 bar
P0136.ai
0
10
20
30
40
Q [l/min]
Einsatzgrenze
Application limit
242012 16840
p
2
[bar]
p = f (Q) Pressure - Flow rate characteristic p
N
= 100 bar
P0138.ai
0
20
40
60
80
100
140
120
Q [l/min]
Einsatzgrenze
Application limit
156 8 10 12 14420
p
2
[bar]
p = f (Q) Pressure - Flow rate characteristic p
N
= 230 bar
P0140.ai
0
50
100
150
200
250
300
Q [l/min]
Einsatzgrenze
Application limit
9234567810
p
2
[bar]
p = f (I) Pressure adjustment characteristic (Q=1l/min)
P0135.ai
0
200
250
300
150
350
100
50
I [mA]0 200
400
400
800
500
1000
600
1200
700
1400
800
1600
100
200
300
600
p
2
[bar]
p
N
350 barp
N
350 bar
p
N
230 barp
N
230 bar
p
N
160 barp
N
160 bar
p
N
100 barp
N
100 bar
p = f (Q) Pressure - Flow rate characteristic p
N
= 63 bar
P0137.ai
0
10
20
30
40
50
60
90
80
70
Q [l/min]
Einsatzgrenze
Application limit
1812 16840
p
2
[bar]
p = f (Q) Pressure - Flow rate characteristic p
N
= 160 bar
P0139.ai
0
30
60
90
120
150
180
210
Q [l/min]
Einsatzgrenze
Application limit
136 8 10 12420
p
2
[bar]
p = f (Q) Pressure - Flow rate characteristic p
N
= 350 bar
P0141.ai
0
50
100
150
200
250
300
350
Q [l/min]
Einsatzgrenze
Application limit
6234510
p
2
[bar]
400-P-585201-EN-03/03.2017
Series DBDRB-1LG…
4/6
5 Dimensions & sectional view
2
4
1
3
3
4
M
A
= 40 [Nm] 10 %
24
13
M
A
= 10 [Nm] 10 %
M
A
= 2.7 [Nm] 10 %
80.3
107.4
77.8
60.3
35
28
135.4
2
1
3/4−16 UNF
2
A
B
M
A
= 1 [Nm] 10%
Seal kit NBR no. DS-284-N
1)
Item Qty. Description
1 1 O-ring no.017 17.17x1.78 N90
2 1 O-ring no.014 12.42x1.78 N90
3 2 O-ring 16.00x2.00 FKM
4 1 Backup ring 10.70x1.45x1.00 FI0751
IMPORTANT!
1)
Seal kit with FKM (Viton) seals no. DS-284-V
Integral air-bleeding
If necessary, air can be purged from these proportional
pressure-relief cartridges by using the integral air-bleed
screw (Item B). The procedure is as follows:
A Protective cap
B Air-bleed screw
Steps:
1. Remove the protective cap.
2. Slacken the air-bleed screw approx. 2 turns.
3. Switch the pressure-relief cartridge on/off several times
until no more air bubbles escape.
4. Tighten the air-bleed screw (Ma = 1 Nm 10%).
5. Fit the protective cap.
400-P-585201-EN-03/03.2017
Series DBDRB-1LG…
5/6
6 Installation information
IMPORTANT!
To achieve the proportional pressure-relief car
tridge's maximum performance rating, fit the sole
noid coil as shown (with the plug pins at the top).
When fitting the cartridges, note the mounting atti
tude (preferably vertical, with coil down auto
matic air bleed) and use the specified tightening
torque. No adjustments are necessary, since the
cartridges are set in the factory.
ATTENTION!
To prevent any pressure surges, port 1 must be
routed to tank with the least possible back-pres
sure. Any tank pressure acting at port 1 is additive
to the pressure setting at the main port 2.
ATTENTION!
Only qualified personnel with mechanical skills
may carry out any maintenance work. Generally,
the only work that should ever be undertaken is to
check, and possibly replace, the seals. When
changing seals, oil or grease the new seals tho
roughly before fitting them.
7 Manual pressure setting
These inverse proportional pressure-relief cartridges are
equipped as standard with an integral manual pressure set
ting. If a proportional solenoid is faulty, for example, this ma
nual pressure setting enables the required pressure to be
set mechanically. The manual pressure setting can also be
used to make minor pressure adjustments directly at the sy
stem.
IMPORTANT!
Any changes to the manual pressure setting have
a direct effect on the factory settings.
4
C
E
D
13
M
A
= 10 [Nm] ± 10 %
C Protective cap
D Lock nut (13 A/F)
E Adjusting spindle for pressure setting
Setting the pressure manually
Steps:
1. Remove the protective cap.
2. Slacken the lock nut (13 A/F).
3. Unscrew (turn to left) the adjusting spindle (4 A/F) until
the required pressure is set.
4. Tighten the lock nut (13 A/F).
5. Fit the protective cap.
ATTENTION!
To reset the inverse proportional pressure-relief
cartridges to their initial position (the factory set
ting), a constant flow rate and a pressure gauge
that measures the pressure in the main port 2 are
needed. The pressure setting must not exceed
the nominal pressure of the spring range in use.
The procedure is as follows:
Restoring the factory settings
Steps:
1. Solenoid de-energised.
2. Remove the protective cap.
3. Slacken the lock nut (13 A/F).
4. Unscrew the adjusting spindle (4 A/F) to its end-stop,
then screw it in until the pressure on the gauge reaches
the nominal pressure (p
N
) of the spring range in use.
5. Tighten the lock nut (13 A/F).
6. Fit the protective cap.
400-P-585201-EN-03/03.2017
Series DBDRB-1LG…
6/6
8 Ordering code
D = pressure control valve
B = pressure relief function
D = direct acting
R = proportional solenoid
A ... Q = standard model - see relevant data sheets
Z ... R = special features - please consult BUCHER
1 = pressure function 1
L = cavity type AL
G = proportional solenoid, inverse type (pulling)
350 = pressure range …350 bar
230 = pressure range …230 bar
160 = pressure range …160 bar
100 = pressure range …100 bar
063 = pressure range … 63 bar
025 = pressure range … 25 bar
2 = nominal size 2 for pressure ranges 350and230
3 = nominal size 3 for pressure ranges 160and100
4 = nominal size 4 for pressure ranges 063and025
(blank) = NBR (Nitrile) seals (standard)
V = FKM (Viton) seals
(special seals - please contact BUCHER)
1 ... 9 = design stage (omit when ordering new units)
... = voltage e.g. 24 (24 V)
D = current DC
(blank) = ISO 4400 / DIN 43 650 connection with mating plug (standard, IP65)
M100 = ISO 4400 / DIN 43 650 connection without mating plug
for the following plug-variants, please consult Bucher:
J = Junior Timer radial plug connection (IP 65) mating plug not supplied
_
L 350
_
-
1 --BRD 32D G-B 24 D
9 Related data sheets
Reference (Old no.) Description
400-P-040011 (i-32) The form-tool hire programme
400-P-060171 Cavity type AL
400-P-510101 Amplifier unit for proportional valves (1-channel) PBS-3A
400-P-511101 (P-3) Amplifier card, 1-channel for valves with one solenoid, type SAN-535…
400-P-720101 Line-mounting body, type GALA (G3/4”)
E 2017 by Bucher Hydraulics AG Frutigen, CH-3714 Frutigen
www.bucherhydraulics.cominfo.ch@bucherhydraulics.com
All rights reserved.
Data is provided for the purpose of product description only, and must not be construed as warranted characteristics in the legal sense. The
information does not relieve users from the duty of conducting their own evaluations and tests. Because the products are subject to continual
improvement, we reserve the right to amend the product specifications contained in this catalogue.
Classification: 430.305.300.305.305.310