3-Way Pressure-Reducing Cartridge, Size 2…4
Q
max
= 20l/min,p
max
= 250bar
Spool-type design,direct acting,with manual adjustment
Series DDRB-7M…
1/5
Reference: 400-P-260501-EN-01
Issue: 03.2012 / Replaces: D-2.170
S Compact construction for cavity type
AM – 3/4-16 UNF to Bucher standards
S 5 pressure ranges available
S Full-flow secondary pressure relief
S Excellent stability over the whole pressure
and flow range
S Available with hand-knob
S All exposed parts with zinc-nickel plating
S Can be fitted in a line-mounting body
1 Description
Series DDRB-7M... screw-in cartridges are direct acting,
spool-type high performance 3-way pressure-reducing
valves. They are available in sizes 2...4 and have a 3/4-16
UNF mounting thread. The straightforward design delivers
an outstanding price/performance ratio and good pressure/
flow ratings. The valves control the required secondary
pressure in port 3 to the value set with the pressure adjust
ment, and independently of the inlet pressure in port 2. In
control mode, the connection 2 3 opens until the pres
sure in port 3 reaches the preset level. If the pressure rises
above the preset level, the control spool opens the 3 1
connection until balance is restored. These 3-way pres
sure-reducing cartridges function as full-flow pressure relief
valves from port 3 1 as soon as the reduced pressure ri
ses above the valve pressure setting. Five spring ranges
are available in order to obtain precise pressure settings
over the whole of the required pressure range. These 3-way
pressure-reducing cartridges are predominantly used in
mobile and industrial applications for reducing a system
pressure. All external parts of the cartridge are zinc-nickel
plated to DIN 50979 and are thus suitable for use in the
harshest operating environments. If you intend to manufac
ture your own cavities or are designing a line-mounting in
stallation, please refer to the section “Related data sheets”.
2 Symbol
3
2 1
3 Technical data
General characteristics Description, value, unit
Designation 3-way pressure-reducing cartridge
Design Spool-type design, direct acting,
with manual adjustment
Mounting method screw-in cartridge 3/4-16 UNF
Tightening torque 50 Nm ± 10%
Size nominal size 2…4, cavity type AM
Weight 0.20 kg
Mounting attitude unrestricted
Ambient temperature range -25°C … +80°C
400-P-260501-EN-01/03.2012 / Replaces: D-2.170
Series DDRB-7M…
2/5
Hydraulic characteristics Description, value, unit
Maximum operating pressure 250bar
Maximum flow rate 20l/min
Nominal pressure ranges 30bar, 60bar, 100bar, 160bar, 250bar
Pressure adjustment range - 250 bar
- 160 bar
- 100 bar
- 60 bar
- 30 bar
0 … 250 bar (1 turn 43bar)
0 … 160 bar (1 turn 24 bar)
0 … 100 bar (1 turn 19 bar)
0 … 60 bar (1 turn 13bar)
0 … 30 bar (1 turn 5bar)
Leakage flow rate < 40 cm
3
/min (with p
2
250 bar)
with oil viscosity 33 mm
2
/s (cSt)
Flow direction see symbol
Hydraulic fluid HL and HLP mineral oil to DIN 51 524;
for other fluids, please contact BUCHER
Hydraulic fluid temperature range -25°C … +80°C
Viscosity range 10…650mm
2
/s (cSt), recommended 15...250mm
2
/s (cSt)
Minimum fluid cleanliness
Cleanliness class to ISO 4406:1999
class 20/18/15
4 Performance graphs
measured with oil viscosity 33mm
2
/s (cSt)
p = f (Q) Pressure - Flow rate characteristic [p
N
= 30bar]
P0315.ai
0
10
20
30
40
50
0
10
20
30
40
50
p
3
[bar]
Q[l/min]
2016
1
2848412
1
620 0
3 123
p
3
[bar]
p = f (Q) Pressure - Flow rate characteristic [p
N
= 60bar]
P0316.ai
0
20
40
60
80
100
0
20
40
60
80
100
p
3
[bar]
Q[l/min]
2016
1
2848412
1
620 0
3 123
p
3
[bar]
400-P-260501-EN-01/03.2012 / Replaces: D-2.170
Series DDRB-7M…
3/5
p = f (Q) Pressure - Flow rate characteristic [p
N
= 100bar]
P0317.ai
0
25
50
75
100
125
0
25
50
75
100
125
p
3
[bar]
Q[l/min]
2016
1
2848412
1
620 0
3 123
p
3
[bar]
p = f (Q) Pressure - Flow rate characteristic [p
N
= 160bar]
P0318.ai
0
40
80
120
160
200
0
40
80
120
160
200
p
3
[bar]
Q[l/min]
108642426810 0
3 123
p
3
[bar]
p = f (Q) Pressure - Flow rate characteristic [p
N
= 250bar]
P0319.ai
p
3
[bar]
Q[l/min]
108642426810 0
3 123
p
3
[bar]
0
50
100
150
200
250
0
50
100
150
200
250
300 300
400-P-260501-EN-01/03.2012 / Replaces: D-2.170
Series DDRB-7M…
4/5
5 Dimensions & sectional view
With adjusting screw “S”
15.5... 23
59.5... 67
44
39
1
2
3
4
5
2
1
17
22
13
3
25
Ma= 50 [Nm] 10 %
Ma= 50 [Nm] 10 %
E
s
1
4
With hand-knob adjuster “H”
27... 34.5
28
6 Installation information
IMPORTANT!
When fitting the cartridges, use the specified
tightening torque. Set the required pressure with
the adjusting screw (s
1
). After you have set the
valve, lock the adjusting screw with the lock nut.
IMPORTANT!
Air-bleeding: If necessary, air can be purged from
these 3-way pressure-reducing cartridges by us
ing the integral bleed groove (Item E). The proced
ure is as follows:
Steps:
4. Slacken the air-bleed screw (17 A/F) approx.
2 turns.
5. Switch the cartridge (ON/OFF) several times
until no more air bubbles escape.
6. Tighten (Ma = 50 Nm ± 10%) the air-bleed
screw.
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.
Seal kit NBR no. DS-249-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 1 O-ring no. 013 10,82x 1,78 N90
4 2 Backup ring 10,70x1,45x1,0 FI0751
5 2 Backup ring 09,40x1,45x1,0 FI0751
IMPORTANT!
1)
Seal kit with FKM (Viton) seals, no. DS-249-V
400-P-260501-EN-01/03.2012 / Replaces: D-2.170
Series DDRB-7M…
5/5
7 Ordering code
D = pressure-control valve
DR = direct acting pressure reducing cartridge
A ... Q = standard model - see relevant data sheets
Z ... R = special features - please consult BUCHER
7 = pressure function 7 (3-way pressure function)
M = cavity type AM
2 = nominal size 2 for pressure range 25 and 16
4 = nominal size 4 for pressure range 10, 06 and 03
25 = pressure range …250 bar
16 = pressure range …160 bar
10 = pressure range …100 bar
06 = pressure range … 60 bar
03 = pressure range … 30 bar
S = screw adjuster (standard)
H = hand-knob adjuster
(blank) = NBR (Nitrile) seals (standard)
V = FKM (Viton) seals
(special seals - please contact BUCHER)
1 ... 9 = design stage (omit when ordering new units)
-1
_
Ex.
25 -M7B --D-SDR 4
8 Related data sheets
Reference (Old no.) Description
400-P-040011 (i-32) The form-tool hire programme
400-P-040181 Cavity type AM
400-P-720111 Line-mounting body, type GAMA (G3/8”)
E 2015 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: 430.305.305.305.305.355