3-Way Pressure-Reducing Cartridge, Size 10
Q
max
= 70l/min,p
max
= 315bar
Spool-type design,direct acting,with manual adjustment
Series DDRA-7L…
1/5
Reference: 400-P-260701-EN-02
Issue: 04.2020
S Compact construction for cavity type DL
to ISO 7789-27-04-0-07
S 5 pressure ranges available
S Full-flow secondary pressure relief
S Excellent stability over the whole pressure
and flow range
S All exposed parts with zinc-nickel plating
S Can be fitted in a line-mounting body
S Can be fitted in sandwich bodies
1 Description
Series DDRA-7L… screw-in cartridges are size 10, high
performance 3-way pressure-reducing valves with an
M27x2 mounting thread. They are direct acting and have
a spool-type design. The straightforward design delivers an
outstanding price/performance ratio and good pressure/
flow ratings. The valves control the required secondary
pressure in port 1 to the value set with the pressure adjust
ment, and independently of the inlet pressure in port 2. In
control mode, the connection 2→ 1 opens until the pres
sure in port 1 reaches the preset level. If the pressure rises
above the preset level, the control spool opens the 1 → 3
connection until balance is restored. These 3-way pres
sure-reducing cartridges function as full-flow pressure relief
valves from port 1 → 3 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 according to DIN EN ISO 19 598 and are thus suit
able for use in the harshest operating environments. For
self-assembly, please refer to the section related data
sheets.
2 Symbol
1
2 3
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 M27x2
Tightening torque 80 Nm ± 10%
Size nominal size 10, cavity type DL
Weight 0.60 kg
Mounting attitude unrestricted
Ambient temperature range -25°C … +80°C
400-P-260701-EN-02/04.2020
Series DDRA-7L…
2/5
Hydraulic characteristics Description, value, unit
Maximum operating pressure 315bar
Maximum flow rate 70l/min
Nominal pressure ranges 30bar, 60bar, 100bar, 160bar, 250bar
Pressure adjustment range 1 turn ≅ 34bar = pressure range 250 bar
1 turn ≅ 24 bar = pressure range 160 bar
1 turn ≅ 14 bar = pressure range 100 bar
1 turn ≅ 8bar = pressure range 60 bar
1 turn ≅ 5bar = pressure range 30 bar
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]
P0193.ai
0
10
20
30
40
50
0
10
20
30
40
50
p
1
[bar]
Q [l/min]
50 60 7040
30
201020 1030
40
506070 0
p
1
[bar]
p = f (Q) Pressure - Flow rate characteristic [p
N
= 60bar]
P0194.ai
0
20
40
60
80
100
0
20
40
60
80
100
p
1
[bar]
Q [l/min]
50 60 7040
30
201020 1030
40
506070 0
p
1
[bar]
400-P-260701-EN-02/04.2020
Series DDRA-7L…
3/5
p = f (Q) Pressure - Flow rate characteristic [p
N
= 100bar]
P0195.ai
0
30
60
90
120
150
0
30
60
90
120
150
p
1
[bar]
Q [l/min]
50 60 7040
30
201020 1030
40
506070 0
p
1
[bar]
p = f (Q) Pressure - Flow rate characteristic [p
N
= 160bar]
P0196.ai
0
50
100
150
200
250
0
50
100
150
200
250
p
1
[bar]
Q [l/min]
50 60 7040
30
201020 1030
40
506070 0
p
1
[bar]
p = f (Q) Pressure - Flow rate characteristic [p
N
= 250bar]
P0197.ai
0
50
100
150
200
250
0
50
100
150
200
250
315 315
p
1
[bar]
Q[l/min]
50 60 7040
3
0201020 1030
4
0506070 0
1 321
p
1
[bar]
400-P-260701-EN-02/04.2020
Series DDRA-7L…
4/5
Q
L
= f (p) Leakage flow rate characteristic
P0198.ai
0
20
40
60
80
100
120
50 60403020100
p
1
[bar]
Q
L
[cm
3
/min]
DDRA-7L-10-03…
DDRA-7L-10-06…
Q
L
= f (p) Leakage flow rate characteristic
P0199.ai
0
50
100
150
200
250
250200150100500
p
1
[bar]
Q
L
[cm
3
/min]
DDRA-7L-10-10…
DDRA-7L-10-16…
DDRA-7L-10-25…
5 Dimensions & sectional view
72
91.5...99.5
163.5...171.5
Ø 33.8
s
1
5
A
M27X2
17
27
30
2
3
1
1
2
3
5
4
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.
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.
Air-bleeding before commissioning
To ensure proper function, the pressure-reducing cartridge
should be air-bled before commissioning.
Steps:
1. Loosen adjustable version (pos. A), unscrew approx.
2 turns.
2. Apply pressure to port 2 until oil escapes free of air
bubbles from the adjustable version.
3. Tighten adjustable version (pos. A).
(M
A = 30 Nm ± 10%)
Seal kit NBR no. DS-324-N
1)
Item Qty. Description
1 1 O-ring no. 119 ∅23,47x 2,62 N90
2 1 O-ring no.116 ∅18,72x 2,62 N90
3 1 O-ring no. 114 ∅15,54x 2,62 N90
4 2 Backup ring ∅17,10x2,00x1,40 FI0751
5 2 Backup ring ∅15,30x2,00x1,40 FI0751
IMPORTANT!
1)
Seal kit with FKM (Viton) seals, no. DS-324-V
400-P-260701-EN-02/04.2020
Series DDRA-7L…
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)
L = cavity type DL
10 = nominal size 10
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 -L7A --D-SDR 10
8 Related data sheets
Reference (Old no.) Description
400-P-040011 (i-32) The form-tool hire programme
400-P-060201 Cavity type DL
400-P-317101 Sandwich pressure-reducing valve, size 6, type SDDRA-7L…-6…
400-P-326101 Sandwich pressure-reducing valve, size 10, type SDDRA-7L…-10…
400-P-740121 Line-mounting body, type GCLA (G3/4”)
400-P-740122 Line-mounting body, type GCLAA (G3/4”)
E 2022 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: 430.305.305.305.320.355