Inverse Proportional Pressure-Relief Cart., Size 2…4
Q
max
= 24 l/min,p
max
= 300bar
Direct acting, electrically operated
Series DBDSB-1LG…
1/6
Reference: 400-P-585401-EN-03
Issue: 05.2020
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 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 Various plug-connector systems and voltages
are available
S With integral manual pressure setting
S Can be fitted in a line-mounting body
1 Description
Series DBDSB-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 and are thus suitable for use in the harshest op
erating environments. The slip-on coils can be replaced wi
thout opening the hydraulic envelope and can be positioned
at any angle through 360°. If you intend to manufacture your
own cavities or are designing a line-mounting installation,
please refer to the section “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 0.40 kg
400-P-585401-EN-03/05.2020
Series DBDSB-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
300bar
250 bar
1)
Maximum flow rate 24l/min
2)
Nominal pressure ranges (p
N
) …18bar, …45bar, …70bar,
…110bar, …160bar, …250bar
3)
Leakage flow rate 2 → 1 … 0.10l/min = pressure range 18 bar / 45bar
… 0.15l/min = pressure range 70bar
… 0.20l/min = pressure range 110bar
… 0.25l/min = pressure range 160bar / 250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.
2)
Depending on the nominal pressure stage.
3)
For higher pressure to 350 bar can be used the valve DBDTC.
Electrical characteristics Description, value, unit
Supply voltage 12V DC, 24V DC
Control current 12 V = 0…1400 mA, 24 V = 0…700 mA
Power consumption at max. control current max. 19 W
Coil resistance R - cold value at 20°C
- max. warm value
12 V = 5.8Ω/24V = 21Ω
12 V = 8.6Ω/24V = 32Ω
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 / IP 67 / IP 69K, see “Ordering code”
(with appropriate mating connector and
proper fitting and sealing)
Electrical connection DIN EN 175301-803, 3-pin 2 P+E (standard)
for other connectors, see “Ordering code”
400-P-585401-EN-03/05.2020
Series DBDSB-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)
P0148.ai
0
40
30
50
20
10
I [mA]0 200
400
400
800
500
1000
600
1200
700
1400
100
200
300
600
p
2
[bar]
p
N
45 barp
N
45 bar
p
N
18 barp
N
18 bar
p = f (Q) Pressure - Flow rate characteristic p
N
= 18 bar
P0158.ai
0
5
10
15
20
25
Q [l/min]
Einsatzgrenze
Application limit
24812162040
p
2
[bar]
p = f (Q) Pressure - Flow rate characteristic p
N
= 70 bar
P0161.ai
0
20
40
60
80
100
Q [l/min]
Einsatzgrenze
Application limit
1586101214240
p
2
[bar]
p = f (Q) Pressure - Flow rate characteristic p
N
= 160 bar
P0162.ai
0
50
100
150
200
250
Q [l/min]
Einsatzgrenze
Application limit
968240
p
2
[bar]
p = f (I) Pressure adjustment characteristic (Q=1l/min)
P0149.ai
0
200
150
250
100
50
I [mA]0 200
400
400
800
500
1000
600
1200
700
1400
100
200
300
600
p
2
[bar]
p
N
250 barp
N
250 bar
p
N
160 barp
N
160 bar
p
N
110 barp
N
110 bar
p
N
70 barp
N
70 bar
p = f (Q) Pressure - Flow rate characteristic p
N
= 45 bar
P0159.ai
0
10
20
30
40
50
60
70
Q [l/min]
Einsatzgrenze
Application limit
188121640
p
2
[bar]
p = f (Q) Pressure - Flow rate characteristic p
N
= 110 bar
P0160.ai
0
30
60
90
120
150
180
Q [l/min]
Einsatzgrenze
Application limit
136 8 10 12240
p
2
[bar]
p = f (Q) Pressure - Flow rate characteristic p
N
= 250 bar
P0163.ai
0
50
100
150
200
300
Q [l/min]
Einsatzgrenze
Application limit
6451230
p
2
[bar]
250
400-P-585401-EN-03/05.2020
Series DBDSB-1LG…
4/6
5 Dimensions & sectional view
56.4
74.4
78.4
107.4
Ø36
28
135.4
4
3
1
4
2
Ma =40 [Nm] ±10 %
24
3
13
Ma =10 [Nm] ±10 %
Ma =2.7 [Nm] ±10 %
2
1
2
A
B
Ma =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-585401-EN-03/05.2020
Series DBDSB-1LG…
5/6
6 Installation information
IMPORTANT!
To achieve the maximum performance rating, fit
the solenoid coil as shown (with the plug pins at
the bottom) and install the valve in a steel body.
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
The inverse proportional pressure relief cartridges are
equipped with emergency pressure adjustment as stan
dard. If the electrical control fails, the preset maximum pres
sure value is set. This can be lowered mechanically to a de
sired pressure value. This emergency pressure setting is
not intended for pressure value adjustments in solenoid
operation.
IMPORTANT!
Any changes to the emergency pressure setting
have a direct effect on the factory settings.
4
C
E
D
13
Ma =1 0 [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 (pN) of the spring range in use.
5. Tighten the lock nut (13 A/F).
6. Fit the protective cap.
400-P-585401-EN-03/05.2020
Series DBDSB-1LG…
6/6
8 Ordering code
D = pressure control valve
B = pressure relief function
D = direct acting
S = standard solenoid (proportional)
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)
250 = pressure range …250 bar
1)
160 = pressure range …160 bar
110 = pressure range …110 bar
070 = pressure range … 70 bar
045 = pressure range … 45 bar
018 = pressure range … 18 bar
2 = nominal size 2 for pressure ranges 250and160
3 = nominal size 3 for pressure ranges 110and70
4 = nominal size 4 for pressure ranges 45and18
(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) = DIN EN 175301-803 connection with mating plug (standard, IP65)
M100 = DIN EN 175301-803 connection without mating plug
C = Kostal plug connection (IP65)
JT = Junior Timer radial plug connection (with protection diode, IP65)
IT = Junior Timer axial plug connection (with protection diode, IP65)
D = Deutsch plug connection 45° DT04-2P (IP67/69K) mating plug not supplied
DT = Deutsch plug connection 45° DT04-2P (with protection diode, IP67/69K)
S = AMP Superseal 1.5 (IP67) / Metri-Pack 150 (IP65) plug connection
F = flying leads (500 mm)
_
L 250
_
-
1 --BSD 32D G-B 24 D
1)
for higher pressure to 350 bar can be used the valve DBDTC.
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-120110 (W-2.141) Coils for screw-in cartridge valves
400-P-510101 Amplifier unit for proportional valves (1-channel) PBS-3A
400-P-585211 Inverse Prop. Pressure-Relief Cart., Size 2..4, type DBDTC-1LG…
400-P-720101 Line-mounting body, type GALA (G3/4”)
E 2020 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