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Reference: 100-P-0000047-E-12
Issue: 10.2024
Proportional Directional Valves
Series L.8S
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Contents Page
1 General
description 5
..................................................................
1.1 Note
on
the
unique
identification
of
the
various
sections 6
............................
2The
main
components 7
...............................................................
2.1 Inlet-
and
end
sections
for
valve
blocks 7
...........................................
2.2 Inlet
and
intermediate
sections 7
..................................................
2.3 Directional
valves 7
.............................................................
2.4 Auxiliary
valves 8
...............................................................
2.5 General
technical
data 8
.........................................................
3 Inlet
sections 9
.......................................................................
3.1 Inlet
sections
without
function 9
...................................................
3.2 Inlet
sections
with
pressure
relief 10
................................................
3.3 Inlet
sections
with
2-way
compensator 12
...........................................
3.4 Inlet
sections
with
3-way
compensator 13
...........................................
4 Intermediate
sections 18
................................................................
4.1 Intermediate
sections
with
no
control
function 18
.....................................
4.2 Intermediate
sections
with
2-way
pressure
compensator 19
............................
4.3 Intermediate
sections
with
3-way
pressure
compensator 20
............................
4.4 Intermediate
sections
with
priority
function 22
........................................
4.5 Intermediate
sections
with
multi-way
pressure
compensator 23
.........................
4.6 Intermediate
section
with
proportional
pressure
reducing
valve 25
......................
5 Directional
valves 27
...................................................................
5.1 LA8S-/
LF8S-
Directional
valves 27
.................................................
5.2 LD8S-/
LC8S-
Directional
valves 33
................................................
5.3 LM8S-/
LP8S-
Directional
valves 41
................................................
5.4 LH8S-Directional
valves 47
........................................................
6 Auxiliary
valves
that
bolt-on
to
the
top
flange
face
O52
.....................................
6.1 Anti-shock
/
make-up
valves
(secondary
pressure
relief) 52
............................
6.2 Check
valves
(pilot
operated
non
return
valves) 54
...................................
6.3 Load
check
valves
with
anti-shock
/
make-up
valves
(pilot
operated
non-return
valve
with
pressure
relief
on
the
actuator
side) 57
...................
6.4 Load
control
valves 59
............................................................
7 Auxiliary
valves
that
bolt-on
to
the
bottom
flange
face
U61
..................................
7.1 Individual
pressure
compensator
without
/
with
flow
cut-off
(torque-limiting) 61
............
7.2 Flow
limiter
without
/
with
individual
pressure
compensators 63
.........................
7.3 Pressure
reducing
compensators 65
................................................
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L.8S directional valves
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8End
sections 68
.......................................................................
8.1 End
sections
with
no
control
function 68
.............................................
8.2 Priority
section 69
................................................................
8.3 With
direct-acting
pressure
relief 71
................................................
8.4 With
pressure
reducing
function
e.g.
for
hydraulic
joystick 72
...........................
8.5 Load
control
valve
with
float
position 73
.............................................
8.6 Safety
valve
for
electro-hydraulic
steering
systems 75
.................................
9 Accessories 77
........................................................................
9.1 Seat
valves
series
SVH04 77
......................................................
9.2 Analogue
systems 78
.............................................................
9.3 Proportional
amplifier 78
..........................................................
9.4 Assembly
kit 78
..................................................................
10 Liability 78
............................................................................
11 Note 78
...............................................................................
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1 General description
The L.8S valve series was developed for mobile applica
tions and it features a robust design and small external di
mensions.
The L.8S valve range is a very flexible building-block sys
tem - its elements can be selected and assembled into a
valve block that provides the necessary functions and pre
cisely meets the needs of the application.
1
2
3
4
5
6
7
8
9
10
Description
1 Inlet section with 3-way compensator
(chapter 3)
2 Directional sections with flange face for auxiliary
valve, and integral individual pressure com
pensator / solenoid, direct-acting (chapter 5)
3 Auxiliary valves that bolt-on to the top flange
face O (chapter 6)
4 Directional valve with direct-acting proportional
solenoid (chapter 5)
5 Directional sections with port threads and flange
face for auxiliary valve / solenoid, two-stage
(chapter 5)
6 Auxiliary valves that bolt-on to the bottom flange
face U (chapter 7)
7 Directional valve manually operated
(chapter 5)
8 Directional valve manually operated
(chapter 5)
9 End section (with no control function)
(chapter 8)
10 Tie-rod (chapter 9.4)
The following components are available within the range:
Block termination components
- inlet sections
- end sections
Intermediate sections
- 2-way pressure compensators
- 3-way pressure compensators
- multi-way pressure compensators
Directional valves with auxiliary valves
- load check valves
- anti-shock valves
- individual pressure compensators (2-way)
and many more.
Within the valve block, directional valve sections are con
nected in parallel to the pressure, tank and control lines.
In a system with a fixed-displacement pump, a typical valve
block contains a 3-way compensator, several directional
valves and the necessary block termination components.
The pump is connected to the valve block by a pressure line.
When all directional valves are in the neutral position, the
control line unloads the 3-way compensator to tank. The en
tire flow supplied to the valve therefore passes - with min
imal unloaded pressure drop - through the 3-way com
pensator to the tank port or the carry-over port.
When one of the directional valves is operated, the load
pressure is signaled through the control line to the 3-way
compensator. The 3-way compensator keeps the pressure
difference between the pressure and control galleries inside
the block at a constant level (the control pressure). The flow
rate to the actuator is therefore always independent of the
load and proportional to the open flow area of the metering
orifice in the directional valve that has been operated.
In a system with a pressure-controlled, variable-displace
ment pump, a typical valve block contains (in addition to the
directional valves and block termination components) a
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2-way compensator that must be positioned between the
pump port and the pressure gallery inside the block.
When all directional valves are in the neutral position, the
2-way compensator closes the inlet to the valve block.
When one of the directional valves is operated, the 2-way
compensator reduces the inlet pressure to a level sufficient
to keep the pressure difference between the pressure and
control galleries inside the block at a constant level. This en
sures that the flow rate to the actuator is independent of the
load and proportional to the open flow area of the metering
orifice in the directional valve. The flow rate supplied to the
valve block therefore matches the actual demand.
When a valve block is supplied by a variable-displacement
pump with a load-sensing control. the pump can be connec
ted directly to the valve block by a pressure line. In addition,
the control line is connected to the pump control port. If the
control pressure can be adjusted directly at the pump con
trol, it is then possible to set the actuator flow rate to the spe
cified value without any additional measures.
If the pump control pressure is preset, the specified flow rate
is achieved by placing a 2-way compensator before the dir
ectional valve.
When all directional valves are in the neutral position, the
pump is de-stroked. When one of the directional valves is
operated then, due to the effect of either the pump control
or the 2-way compensator positioned before the directional
valve, the necessary control pressure is maintained
between the pressure and control galleries inside the block.
The flow to the selected actuator is therefore independent
of the load and proportional to the open flow area of the
metering orifice in the directional valve.
In all of the system configurations described up to this point,
when several directional valves are operated then, thanks
to the shuttle valves situated in the control lines, the actuator
with the highest load will dictate the control pressure and the
flow rate to the actuator will be independent of the load and
proportional to the open flow area of the metering orifice in
the directional valve. Load-independence for the less
highly-loaded actuators can be achieved by using individual
pressure compensators, which reduce the excessive pres
sure difference sufficiently to ensure that the required con
trol pressure exists at the corresponding directional valve.
1.1 Note on the unique identification of the various sections
For all adjustable sections (auxiliary-function sections and
directional sections), the flow rate specification Q= and
pressure specification P= must be stated clearly and within
the limits of the prescribed flow rate and pressure specifica
tions. These can be found in the relevant document section.
1.1.1 Example
Example 1:
LU8SSCS-0M22**00/P= => LU8SSCS-0M22*00/P=210
Example 2 with spool stroke limiter:
LD8SE4A2525-S*L-1M18T18*00/P= => LD8SE4A2525-S*L-1M18T18*00/P=180QA=18QB=21
The products are assembled in accordance with the specified setting parameters.
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2 The main components
2.1 Inlet- and end sections for valve
blocks
Every L.8S series valve block requires two block termina
tion components in the form of one inlet section and one end
section. These two components are used for mounting the
block, the block tie bolts pass through them, and they are
provided with hydraulic ports.
2.2 Inlet and intermediate sections
2.2.1 2-way pressure compensator
The 2-way compensator is a valve that controls a pressure
differential. It is situated inside the block, before the pressu
re gallery. In this valve, the inlet pressure is reduced by the
amount needed to ensure that the control pressure between
the pressure and control galleries inside the block is kept
constant. In some models, the valve closes the inlet to the
block if the pressure in the control line reaches the setting
of an upstream pressure relief valve.
The 2-way compensator can be supplied as an inlet section
or an intermediate section.
2.2.2 3-way pressure compensator
The 3-way compensator is a valve that controls a pressure
differential. It is situated between the pressure gallery and
the tank or carry-over gallery. The valve keeps the pressure
difference between the pressure and control galleries inside
the block at a constant level and surplus flow passes to the
tank or carry-over port. If the pressure in the control line
reaches the setting of an upstream pressure relief valve, the
3-way compensator opens the connection to tank, thus lim
iting the pressure in the pressure gallery inside the block. In
one particular model, the function of the 3-way compensator
can be customized to suit the requirements of individual ap
plications. The adjustment can be done with a shut-off
screw that is accessible from the outside.
2.3 Directional valves
The control options (LA, LF, LH, LC and LP or ON/OFF (LM,
LD) for L.8S series directional valves enable continuous
changes to the flow area of the metering orifice, which in turn
determines the flow rate that is supplied to the actuator. This
is achieved by arranging that in the first group of valves the
spool can stop at any desired point along its total stroke,
whereas the spools of LM/LD valves travel from one end of
the stroke to the other when they are switched, and do not
stop at intermediate positions.
The various directional valves are differentiated by their
type of operation. The LA directional valves are mechanic
ally operated by hand lever. The LF directional valves are
mechanically operated by remote cable. The LD and LC dir
ectional valves are electrically operated, direct acting. The
LM and LP directional valves have electro-hydraulic opera
tion. The solenoids of LD, LC, LM and LP directional valves
are fitted with a manual override as standard, but in the case
of the LM and LP valves the overrides only work if pressure
is present at the valve inlet. Series LD, LC, LH, LM and LP
directional valves can be equipped with an optional hand
lever for manual-override operation of the valve spool.
Operating two valves in parallel is dependent on the
pressure demands of the actuator connected to each valve.
However, the LD-, LC-, LA- and LF- directional valves can
optionally be ordered with an integral individual pressure
compensator.
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2.4 Auxiliary valves
The auxiliary valves fit onto the directional valves and can
be flange-mounted on the top (connection face O) or bottom
(connection face U) of the valve, which is specially designed
for this purpose.
For mounting on connection face O, these alternative auxili
ary valves are available:
- anti-shock valve (secondary pressure relief valve
with make-up facility)
- load control valve
- load check valve (hydraulically and electrically pilot-
operated check valve)
- various special bolt-on plates
Anti-shock valves are used to prevent over-pressure in the
actuator lines and/or cavitation with negative loads.
Load control valves provide controlled, load-independent
lowering of over-running (pulling) loads. The anti-shock
function is integrated and optimal adjustable.
Load check valves hold the actuator, which may be under
load, with virtually zero leakage. The actuator is released by
applying pressure to the other actuator port.
For mounting on connection face U, these alternative auxili
ary valves are available:
- individual pressure compensator
- flow limiter
- pressure-reducing compensator
An individual compensator is used when the flow rate to the
actuator must be independent of load, but the inlet com
pensator cannot perform the necessary pressure-control
function. LA-, LC-, LD and LF-directional valves are also
available with integrated individual pressure compensator.
Additional function blocks are described in detail in the rel
evant sections.
2.5 General technical data
General characteristics Unit Description,value
Recommended mounting attitude With spool axis horizontal
Nominal flow rate l/min max. 150
Actuator flow rate l/min max. 60
Inlet pressure P +D bar max. 300
2)
Actuator pressure A + B bar max. 300
2)
Intermittent pressure (max. 10 sec/min) bar max. 315
Return line pressure bar max. 40
1)
Hydraulic fluid Recommendation: high-quality fluids with a mineral-oil
base, such as HLP oils to DIN 51524 part 2
Seal material NBR
Fluid temperature °C -25 … +80
Ambient temperature °C -25 … +50
Viscosity range mm
2
/s 10 … 375
Minimum fluid cleanliness level ISO 446 code 20/18/15
Nominal voltage range of switching solenoids V DC 12V ¢ 10,8 … 14
24V ¢ 21,6 … 28
Servo frequency Hz preferably 100
Threaded ports to DIN 3852 and DIN ISO 228-1
Tie-rod M8, tensile grade 10.9 (tightening torque 30Nm)
Corrosion protection Valve blocks primed colour: black RAL 9005
coating thickness 30 to 50 m
3)
MTTF
D
values 150 years, see datasheet 100-KB-000083
1) 100 bar return line pressure for brief periods, with max. inlet pressure 210 bar. 210 bar for P and T in individual cases. For higher pressures, contact Bucher
Hydraulics.
2) The stated pressures are the maximum absolute pressure limits for a tank line pressure of 10 bar.
Note: Some components have lower individual pressure ratings.
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3 Inlet sections
3.1 Inlet sections without function
3.1.1 Description
Inlet sections without function are used to begin the block
when no control functions are needed (e.g. LS applica
tions). Ports P, T and LS, and tapped holes for securing the
valve block are provided.
3.1.2 Overview of sections
Symbol Description Part number
T
P/D
LS
T
D
LS
LU8SPOG-0M22*00 100020638
without function
port threads to DIN 3852 - M22 x 1,5
T
P/D
LS
T
D
LS
LU8SPOG-0M26*00 100020639
without function
port threads to DIN 3852 - M26 x 1,5
3.1.3 Dimensions
LS T
D
P
102
M8
2,5
19
29
33
29
34,5
62
16,5
M14x1,5
M22x1,5
53
M22x1,5
11,5
119,5
88
10
9
13
46
51,5
Minimum length for calculating
the total tie-rod length
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3.2 Inlet sections with pressure relief
3.2.1 Description
3.2.1.1 Inlet pressure relief two-stage LU8SPOD
This is used to begin the block, and has an integral two-
stage pressure relief function (e.g. safety pressure relief in
an LS system). Ports P, T and LS, and tapped holes for se
curing the valve block are provided.
3.2.1.2 Inlet pressure relief direct acting LU8SPOS
This is used to begin the block, and has an integral direct-
acting pressure relief function (e.g. secondary pressure re
lief in an LS system). The application limits must not be ex
ceeded. By screwing in damping and bypass orifices, many
possibilities for combating oscillation problems in LS sys
tems can be created. Ports P, T and LS, and tapped holes
for securing the valve block are provided.
3.2.2 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Nominal flow rate l/min see performance graphs 3.2.3
Pressure relief bar adjustable
3.2.3 Performance graphs
3.2.3.1 Inlet pressure relief two-stage
LU8SPOD
250
200
150
100
50
0
0 20406080100
300
120
Q
T
[l/min]
P -> [bar]
3.2.3.2 Inlet pressure relief direct acting
LU8SPOS
250
200
150
100
02040
300
60 80 100
Dp
P
!
T
[bar]
application
limit
Q
T
[l/min]
3.2.4 Overview of sections
3.2.4.1 Inlet pressure relief two-stage
Symbol Description Part number
T
LS
T
LSP
P
LU8SPOD-0M22*00/P= see order details chapter 1.1
relief adjustment range 60 … 300 bar
nominal flow rate 120 l/min
pressure relief adjustable P =
port threads to DIN 3852 - M22 x 1,5
Specify the pressure relief setting in bar
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T
LS
T LSP
P
LU8SPOD-0M26*00/P= see order details chapter 1.1
relief adjustment range 60 … 300 bar
nominal flow rate 120 l/min
pressure relief adjustable P =
port threads to DIN 3852 - M26 x 1,5
port thread pressure M22 x 1,5
port thread tank M26 x 1,5
Specify the pressure relief setting in bar
3.2.4.2 Inlet pressure relief direct acting
Symbol Description Part number
T
P
LS
T
P
LS
LU8SPOS1-0M22*00/P= see order details chapter 1.1
application limit see performance graph
relief adjustment range 35 … 95 bar P =
port threads to DIN 3852 - M22 x 1,5
Specify the pressure relief setting in bar
T
P
LS
T
P
LS
LU8SPOS2-0M22*00/P= see order details chapter 1.1
application limit see performance graph
relief adjustment range 95 … 210 bar P =
port threads to DIN 3852 - M22 x 1,5
Specify the pressure relief setting in bar.
T
P
LS
T
PLS
LU8SPOS3-0M22*00/P= see order details chapter 1.1
application limit see performance graph
relief adjustment range 210 … 300 bar P =
port threads to DIN 3852 - M22 x 1,5
Specify the pressure relief setting in bar.
3.2.5 Dimensions
3.2.5.1 LU8SPOD-…
38 43 24,5
M14x1,5
M22x1,5
M22x1,5
M8
134,5
176
10
4
13
13
84
102
2,5
15
19
24,5
27
50
55
Minimum length for calculating the total tie-rod length
3.2.5.2 LU8SPOS-…
Minimum length for calculating the total tie-rod length
12.552.5
45
13
11.5
172
48
2.5
102
120
47
84
30
M14x1,5
19 13
M8
28
19
M22x1,5
M22x1,5
LS
55
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3.3 Inlet sections with 2-way compensator
3.3.1 Description
These are used to begin the block and have an integral
2-way compensator; optionally with flow cut-off from a pre-
set pressure. A typical application is the parallel operation
of two valve blocks in an LS-system, where only one spool
at a time is operated within each block. Ports P and LS, and
tapped holes for securing the valve block are provided. The
tank connection must be implemented in the intermediate or
end section.
3.3.2 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Nominal flow rate l/min 100
Pressure relief bar adjustable, 50 … 300
Port threads to DIN 3852 bar M22x1,5
3.3.3 Performance graphs
3.3.3.1 Variation of the actuator flow rate with inlet
pressure when using an LU8SSKA / SKB
inlet section
50
40
30
20
10
0
0 50 100 150 200 250
70
60
300
10
16
25
40
63
Actuator flow rate
Q [l/min]
Spool size
Inlet pressure P [bar]
3.3.3.2 Flow cut-off function with an LU8SSKB inlet
section
50
40
30
20
10
0
0 50 100 150 200 250
70
60
300
Actuator flow rate
Q [l/min]
ΔPP -> [bar]
3.3.4 Overview of sections
Symbol Description Part number
P
LS
PLS
LU8SSKA-0M22*00 100022874
control Δp = 12 bar / without flow cut-off
P
LS
T
LSP
LU8SSKB-0M22*00/P= see order details chapter 1.1
control Δp = 12 bar / with flow cut-off
Specify the pressure relief setting in bar
3.3.5 Dimensions
14
19
50
50,5
26,5
M22x1,5
M14x1,5
83
122
13
10
M8
10
102
123
134
2
only with
LU8SSKB..
Screw-in depth for calculating
the total tie-rod length
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3.4 Inlet sections with 3-way compensator
3.4.1 Description
These are used to begin the block and have an integral
3-way compensator; optionally with the additional functions
shown below. These inlets are used with fixed displacement
pumps.
In essence, they can be applied in conjunction with a fixed-
displacement pump for control of unloading and flow control
that is independent of the load.
LU8SSCK
Provides a 3-way compensator function with the facility to
change over to LS- or constant pressure systems. This is
typical with towed harvesters.
LU8SSCK*29
Provides a 3-way compensator function, with the ability to
change over to LS or constant-pressure systems.
In the case of reduced flow rates caused by increased
pressure losses in the P line, or if the load sensing line has
a large leakage or is connected to tank through an orifice
(bleed-off), the integral adjustable pressure booster can
amplify the LS signal accordingly.
In special cases, increased amplification of the LS signal
can result in higher actuator flow rates and thus increase
the performance of the system.
LU8SSCL
Provides a 3-way compensator function and two-stage
pressure relief that is adjustable from outside the valve,
with the ability to change over to LS or constant-pressure
systems. This is typical with towed harvesters. The pres
sure relief is only operative in the open system.
LU8SSCS
Provides a 3-way compensator function and 2-stage
pressure relief that is adjustable from outside the valve.
LU8SSCU
Provides a 3-way compensator function with an
independent system pressure relief function.
LU8SSCX
Provides a 3-way compensator function and two-stage
pressure relief that is adjustable from outside the valve,
and an independent system pressure relief function. The
surplus flow is available at port D for other applications.
The valve block's own functions have priority over port D.
The valve block can be protected at a lower pressure set
ting by the two-stage relief valve, so that excess flow is al
ways available at port D.
LU8SSCW
Provides a 3-way compensator function with an inde
pendent system pressure relief function. The surplus flow
is available at port D for other applications. The valve
block's own functions have priority over port D. When the
valve block's pressure relief function is active, there is no
longer any flow to port D.
LU8SSCE
Provides a 3-way compensator function with an inde
pendent system pressure relief function. When it is de-en
ergised, a 2/2 seat valve unloads the internal LS line to
tank, which means that the seat valve must first be ener
gised before the valve block is functional. Applications
are in safety circuits, e.g. emergency stop controls.
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L.8S directional valves
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3.4.2 General technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Nominal flow rate l/min 120
Unloaded pressure P -> T (D) bar see performance graphs chapter 3.4.3
Pressure relief bar adjustable, 50 … 300
2)
Nominal voltage
1)
V DC 12 or 24
Plug type AMP Junior Timer, Deutsch DT04-2P-EP04
Power consumption
1)
Watt 27
Duty cycle
1)
% 100
Protection class
1)
AMP: IP65 DT: IP67 (DIN EN 60529)
1) Only with LU8SSCE. 2) Higher pressures on enquiry.
3.4.3 Performance graphs
3.4.3.1 Maximum flow rate at directional valve
(without individual pressure compensator)
when using an LU8SSC inlet section.
40
20
0
02040
Intel flow Q
In
[l/min]
60
60
80 100
120
63
40
25
16
10
80
75
100
Actuator flow Q
Act
[l/min]
Spool size
3.4.3.2 Unloaded pressure in neutral position,
(for other unloaded pressures consult
Bucher Hydraulics).
20
16
12
8
4
0
02040
Intel flow Q
In
[l/min]
60 80 100 120
for LU8SSCW/SCX
when Dp D-T > 20 bar
P -> T [bar]
SC.
3.4.3.3 Two-stage pressure relief characteristic
inlet section LU8SSCS / SCX
200
160
120
80
40
0
020 40
Q
T
[l/min]
280
240
60 80 100
P -> T [bar]
3.4.3.4 System pressure relief characteristic
inlet section LU8SSCE / SCU / SCW / SCX
200
160
120
80
40
0
02040
Q
T
[l/min]
280
240
60 80 100
P -> T [bar]
3.4.4 Overview of sections
Symbol Description Part number
TP
P
T
LS
LS
LU8SSCK-0M22*00 100020640
without pressure relief
compensator can be disabled for LS systems
control Δp = 12 bar with active pressure compensator
port threads to DIN 3852 - M22 x 1.5
100-P-0000047-E-12/10.2024
L.8S directional valves
15/79
T
P
LS
TP LS
LU8SSCK-0M22*04 100020641
without pressure relief
compensator can be disabled for LS systems
for using with seat valves SVH04M - straight-through tie bolts
control Δp = 12 bar with active pressure compensator
port threads to DIN 3852 - M22 x 1.5
TP
P
T
LS
LS
LU8SSCK-0M22*12 100030622
without pressure relief
compensator can be disabled for LS systems
for using with seat valves SVH04M - straight-through tie bolts
control Δp = 12 bar with active pressure compensator
no tank connection for bolt-on functions
port threads to DIN 3852 - M22 x 1.5
TP
P
T
LS
LS
LU8SSCK-0M26*12 100023553
without pressure relief
compensator can be disabled for LS systems
for using with seat valves SVH04M - straight-through tie bolts
control Δp = 12 bar with active pressure compensator
no tank connection for bolt-on functions
port threads to DIN 3852 - M26 x 1.5
T
P
LS
LS+
LS
TP LS LU8SSCK-0M22*29 100036705
without pressure relief
compensator can be disabled for LS systems
with integral LS-compensator, boost pressure 8 bar max.,
factory setting 6 bar.
control Δp = 12 bar with active pressure compensator
port threads to DIN 3852 - M22 x 1.5
TP
P
T
LS
LS
LU8SSCL-0M22*00/P= see order details chapter 1.1
with two-stage pressure relief in fixed-displacement pump system
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar
TP
P
T
LS
LS
LU8SSCL-0M22*04/P= see order details chapter 1.1
with two-stage pressure relief in fixed-displacement pump system
for using with seat valves SVH04M - straight-through tie bolts
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar
TP
P
T
LS
LS
LU8SSCS-0M22*00/P= see order details chapter 1.1
with two-stage pressure relief
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar
TP
P
T
LS
LS
LU8SSCS-0M26*00/P= see order details chapter 1.1
with two-stage pressure relief
control Δp = 12 bar
port threads to DIN 3852 - M26 x 1.5
Specify the pressure relief setting in bar
100-P-0000047-E-12/10.2024
L.8S directional valves
16/79
T
P
LS
LU8SSCS-0M22*04/P= see order details chapter 1.1
with two-stage pressure relief
for using with seat valves SVH04M - straight-through tie bolts
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar
TP
P
T
LS
LS
LU8SSCU-0M22*00/P= see order details chapter 1.1
with system pressure relief, direct acting,
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar, (50 … 315 bar)
TP
P
T
LS
D
LS
LU8SSCW-0M22*00/P= see order details chapter 1.1
with system pressure relief
with surplus-flow port
internal valve block has priority over D
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar, (50 … 315 bar)
TP
P
T
LS
D
LS
LU8SSCW-0M26*00/P= see order details chapter 1.1
with system pressure relief
internal valve block has priority over D
with surplus-flow port
control Δp = 12 bar
port threads to DIN 3852 - M26 x 1.5
Specify the pressure relief setting in bar, (50 … 315 bar)
TP
P
T
LS
D
LS
LU8SSCX-0M22*00/P=P1= see order details chapter 1.1
with system pressure relief
with surplus-flow port
internal valve block has priority over D
with pressure relief for the valve block
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar, (50 … 315 bar)
TP
P
T
LS
LS
LU8SSCE-0M22J24*00/P= see order details chapter 1.1
with direct-acting pressure relief function
emergency stop function
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
plug type: AMP Junior Timer
nominal voltage 24 V DC
Specify the pressure relief setting in bar
3.4.5 Connector socket
AMP Junior Timer
J
Deutsch plug DT04-2P-EP04
T
100-P-0000047-E-12/10.2024
L.8S directional valves
17/79
3.4.6 Dimensions
3.4.6.1 LU8SSCE-…G
27
19
29
60
15
43
M22x1,5
24,5
M22x1,5
M8
44
99,5
134,5
232
10
2,5
29
13
10
84
Screw-in depth for
calculating the total
tie-rod length
P
T
3.4.6.2 LU8SSCK / SCS / SCL
38
43
M22x1,5
M14x1,5
M22x1,5
24,5
2,5
13
84
10
M8
102
10
4
134,5
175
27
15
19
29
50
57
P1
Minimum length for
calculating the total tie
rod length for special
feature, eg. /04
Screw-in depth for
calculating the total
tie-rod length
(Special feature / 04
is straight-through tie-rod)
only for LU8SSCK/SCL
only for LU8SSCS/SCL
3.4.6.3 LU8SSCU / SCW / SCX
only for
LU8SSCU
200
27
15
19
29
60
M22x1,5
47,5
38
43
24,5
M22x1,5
M14x1,5
M22x1,5
84
10
13
M8
44
99,5
134,5
10
2,5
29
P1
P
Screw-in depth for
calculating the total
tie-rod length
only for LU8SSCX
100-P-0000047-E-12/10.2024
L.8S directional valves
18/79
4 Intermediate sections
4.1 Intermediate sections with
no control function
4.1.1 Description
These intermediate sections are used as spacer section
(e.g. with large port fittings) or, in the case of the
LU8SBTP-0; for hydraulic partitioning of the P and LS lines
within the valve block; T is continuous.
4.1.2 Overview of sections
Symbol Description Part number
TP LS
TP LS
LU8SBDP-0*00 100020651
block spacer section
P, T and LS continuous
TP LS
TP LS
LU8SBTP-0*00 100020652
block partition section
P and LS blocked, T continuous
TP LS
LS
TP LS
LU8SBTL-0M14*00 100024522
block partition section
P blocked, T continuous, LS in front half of block to T,
in rear half to separate LS port.
port threads to DIN 3852 - M14 x 1,5
4.1.3 Dimensions
4.1.3.1 LU8SBDP / BTP
80
110
7,5
4.1.3.2 LU8SBTL
10
6.5
72.5
110
80
35
15
M14x1,5
100-P-0000047-E-12/10.2024
L.8S directional valves
19/79
4.2 Intermediate sections with
2-way pressure compensator
4.2.1 Description
These are intermediate sections with an integral 2-way
compensator, optionally with flow cut-off from a pre-set
pressure. Typical applications: valve block sections that, in
general, experience lower pressures are combined with this
compensator to ensure load-independent operation. Ports
P and LS are provided.
4.2.2 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Nominal flow rate l/min see performance graphs 4.2.3
Pressure relief valve bar adjustable
4.2.3 Performance graphs
4.2.3.1 Variation of the actuator flow rate with inlet
pressure when using an LU8SSKC / SKD
intermediate section
50
40
30
20
10
0
0 50 100 150 200 250
Inlet pressure P [bar]
70
60
300
10
16
25
40
63
Actuator flow
Q [l/min]
Spool size
4.2.3.2 Flow cut-off function with an LU8SSKD
intermediate section
50
40
30
20
10
0
0 50 100 150 200 250
70
60
300
Dp
P
!
T
[bar]
Actuator flow
Q [l/min]
4.2.4 Overview of sections
Symbol Description Part number
LS
LS
LS
PT
PT
P
LU8SSKC-0M22*00 100021341
nominal flow rate100 l/min
port threads to DIN 3852 - M22 x 1,5
LS
LS
LS
PT
PT
P
LU8SSKD-0M22*00/P= see order details chapter 1.1
nominal flow rate100 l/min
with adjustable pressure relief valve for flow cut-off
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar. (50 … 300 bar)
4.2.5 Dimensions
13,5
51,5
33,5
74
M22x1,5
M14x1,5
3586
42
31
6,5
119
149,5
21,5
Only with LU8SSKD..
100-P-0000047-E-12/10.2024
L.8S directional valves
20/79
4.3 Intermediate sections with
3-way pressure compensator
4.3.1 Description
These 3-way compensators are intermediate sections with
the additional functions shown below. In essence, they can
be applied in conjunction with a fixed-displacement pump
for control of unloading, and flow control that is independent
of the load. Ports P, and D and LS as appropriate, are
provided.
4.3.2 Function
LU8SSBU
Provides a 3-way compensator function with 2-stage
pressure relief, and a reduction in the unloaded pressure
from the standard 12 bar to approx. 6 bar.
LU8SSBK
Includes a 3-way compensator function with the facility to
change over to LS or constant-pressure systems. This is
typical with towed harvesters.
LU8SSBW
Provides a 3-way compensator function and the surplus
flow is available at port D or internally for other
applications. Both flows are protected by a two-stage
pressure relief valve. On reaching the maximum pressure
in the priority side, which can then be loaded up to the
maximum pressure setting.
4.3.3 Technical data
General characteristics Unit Description, value
Inlet pressure
1)
bar max. 300
Nominal flow rate l/min 120
Unloaded pressure P -> T(LU8SSBU/SBT/SBL/SBK) bar see performance graphs chapter 4.3.4
Pressure relief bar adjustable, 50 … 300 bar
Nominal voltage
2)
V DC 12 or 24
Plug type AMP Junior Timer, DT04-2P-EP04
Power consumption
2)
Watt 27
Duty cycle
2)
% 100
Protection class
2)
AMP: IP65 DT: IP67 (DIN EN 60529)
1) Inlet pressure for LU8SSBU-....G.. and LU8SSBW....G.. max. 250 bar. 2) Only with electrical unloading.
4.3.4 Performance graphs
4.3.4.1 Unloaded pressure in neutral position,
LU8SSBW
8
6
4
2
0
02040
Inlet flow [l/min]
60 80 100 120
10
12
with pD = pT
with p D-T > 20 bar
P -> D [bar]
4.3.4.2 Maximum flow rate at directional valve
(without individual pressure compensator)
when using an LU8SSBU / LU8SSBW
40
20
0
02040
Inlet flow Q
In
[l/min]
60
60
80
100 120
63
40
25
16
10
80
75
100
Spool size
Actuator flow rate Q [l/min]
4.3.4.3 Pressure relief characteristic, LU8SSB
200
160
120
80
40
0
02040
Q
T
[l/min]
280
240
60 80 100
P -> T [bar]
4.3.4.4 Unloaded pressure in neutral position,
LU8SSBU / LU8SSBK
SBK
SBU
20
16
12
8
4
0
02040
Inlet flow [l/min]
60 80 100
120
P -> T [bar]
100-P-0000047-E-12/10.2024
L.8S directional valves
21/79
4.3.5 Overview of sections
Symbol Description Part number
LS
TP
T
P
LU8SSBU-0M22*00/P= see order details chapter 1.1
with two-stage pressure relief / control Δp = 12 bar
reduction in the unloaded pressure to approx. 6 bar
port threads to DIN 3852 - M22 x 1,5
Specify the pressure relief setting in bar
LSTP
TD
P
D
LU8SSBW-0M22*00/P= see order details chapter 1.1
with two-stage pressure relief / with surplus flow port
control Δp = 12 bar
port threads to DIN 3852 - M22 x 1.5
Specify the pressure relief setting in bar
LSTP
TD
P
D
LU8SSBW-0M22T24*00/P= see order details chapter 1.1
with two-stage pressure relief / with surplus flow port
control Δp = 12 bar / emergency stop function
port threads to DIN 3852 - M22 x 1.5
plug type to DIN 43650 (others on enquiry) / nominal voltage 24 V DC
Specify the pressure relief setting in bar
LS
LS
T
TP
P
LU8SSBK-0M22*00 100020654
compensator can be disabled for LS systems
control Δp = 12 bar with active pressure compensator
without pressure relief
port threads to DIN 3852 - M22 x 1.5
4.3.6 Connector socket
AMP Junior Timer
J
Deutsch plug DT04-2P-EP04
T
4.3.7 Dimensions
13,5
M22x1,5
51,5
33,5
74
M22x1,5
M14x1,5
35
86
42
31
6,5
32
119
156
222
Only with
LU8SSBU-…. G, T, J
Only with
LU8SSBK
Not with LU8SSBV/SBK
100-P-0000047-E-12/10.2024
L.8S directional valves
22/79
4.4 Intermediate sections with priority
function
4.4.1 Description
The LU8SSB.-0... priority sections contain a priority function
for the directional valves fitted on the appropriate side or for
an external control system and a surplus flow side.
In a under-supply scenario (pump flow < total flow needed
by the valve block), the surplus flow side will receive only a
portion of what it needs, or possibly (pump flow < priority-
flow setting) no flow what ever. Preferred applications are in
LS-systems. The priority side can also be equipped with a
pressure relief valve that ensures a priority-flow cut-off
when the pressure setting is reached.
For oscillation-prone applications, a damping element (e.g.
an accumulator) can be connected to a port specially
(M14x1,5) provided for this purpose.
4.4.2 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Nominal flow rate l/min 120
Unloaded pressure P -> T bar see performance graphs 4.4.3
Pressure for flow cut-off (P
Priority
) bar adjustable, 50 … 300 bar
4.4.3 Performance graphs
4.4.3.1 Flow cut-off on the priority side
140
120
100
80
60
40
0
50 100
150
200 250 300
Q [l/min]
Dp
P
!
T
[bar]
20
4.4.3.2 Pressure drop characteristic
25
20
15
10
5
0
20 40 60 80 100 120 140 160
Q [l/min]
Dp [bar]
0
A
B, C
A = P
pump
port
to P
Surp
(Q
Priority
=zero) at P
Surp
= P
LS
B = P
pump
port
to P
Surp
at p P
Surp
to LS > 20 bar
C = P
pump
port
to P
Priority
(control spool in neutral position)
4.4.4 Overview of sections
Symbol Description Part number
P
Priorität
P
Surp
T
P
LS
P
LS
T
LU8SSBP-0M26*00/P= see order details chapter 1.1
with flow cut-off / port threads to DIN 3852 - M26 x 1,5
Specify the pressure relief setting in bar, (50 … 300 bar)
LU8SSBP-0B10*00/P= see order details chapter 1.1
with flow cut-off / port threads to BSP 1“ / G 1“
Specify the pressure relief setting in bar (50 … 300 bar)
4.4.5 Dimensions
240
76.5
30.5
42.5
160
32
44
82
86
33
30
M
x1.514
M26 x 1,5
P
100-P-0000047-E-12/10.2024
L.8S directional valves
23/79
4.5 Intermediate sections with
multi-way pressure compensator
4.5.1 Description
The multi-way pressure compensators contain a priority
function for the directional valves fitted on the appropriate
side. For the surplus-flow side, a 3-way pressure com
pensator is available for unloading control and load-inde
pendent flow control when using a fixed displacement
pump.
In the under-supply range (pump flow < total flow needed by
the valve block), the surplus flow side will receive only a por
tion of what it needs, or possibly (pump flow < priority flow
setting) no flow whatsoever.
Application preferably in conjunction with a fixed displace
ment pump, but with the ability to change over to LS or con
stant-pressure systems.
Ports P, T, and LS are provided.
4.5.2 Functions
LU8SSMD
Priority-flow control as 2- and 3-way compensator, with
surplus-flow control as 3-way compensator. The priority-
flow side is provided with a flow cut-off function, the
surplus-flow side with two-stage pressure relief.
LU8SSMF
Priority-flow control as 2- and 3-way compensator, with
surplus-flow control as 3-way compensator. The priority-
flow side is provided with a flow cut-off function. The
surplus-flow control can be de-activated, which allows an
LS- or constant-pressure system to be connected. This is
typical with towed harvesters.
4.5.3 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Nominal flow rate l/min 120
Unloaded pressure bar see performance graphs section 4.5.4
Pressure for flow cut-off (P
Priority
) bar adjustable, 50 … 300 bar
Pressure for pressure relief (P
Surp
) bar adjustable, 50 … 300 bar
4.5.4 Performance graphs
4.5.4.1 Maximum flow rate at directional valve
when using an LU8SSM. (priority- and sur
plus side).
40
20
0
02040
Inlet flow Q
In
[l/min]
60
60 80 100 120
63
40
25
16
10
80 75
100
Actuator flow Q [l/min]
Spool size
4.5.4.2 Flow cut-off on the priority side
140
120
100
80
60
40
0
50 100
150
200 250 300
Q [l/min]
Dp
P
!
T
(bar)
20
100-P-0000047-E-12/10.2024
L.8S directional valves
24/79
4.5.4.3 Pressure relief characteristic (priority and
surplus flow) LU8SSM.
240
160
80
0
02040
Q
R/T
[l/min]
60 80 100
P -> R/T [bar]
300
120
4.5.4.4 Unloaded pressure in neutral position
LU8SSM.
20
12
28
4
02040
Inlet flow Q
In
[
l/min
]
60 80 100 120
P -> T [bar]
24
16
8
4.5.5 Overview of sections
Symbol Description Part number
LS
T
T
T
P
LS
P
Surp
P
Priorität
LU8SSMD-0M22*00/P1=P2= see order details chapter 1.1
P
Prior
with two-stage pressure relief
P
Surp
with two-stage pressure relief
control Δp = 12 bar for P
Prior
and P
Surp
port threads to DIN 3852 - M22 x 1,5
Specify the pressure relief setting in bar
T
T
P
T
LS
LS
P
Surp
P
Priorität
LS
LU8SSMF-0M22*00/P= see order details chapter 1.1
P
Prior
with pressure relief
compensator can be disabled on surplus-flow side for LS systems
control Δp = 12 bar for P
Prior
control Δp = 12 bar for P
Surp
with active pressure compensator
port threads to DIN 3852 - M22 x 1,5
Specify the pressure relief setting in bar
4.5.6 Dimensions
LS
P
T
2727
192
177
155
102
2,5 M8
90
34,5
3,5
13
32,5
86
1,5
27,5
44,5
87
M14x1,5
M22x1,5
30
31
47
63
80
94
P1 P2
only with LU8SSMF
only with LU8SSMF
and LU8SSMD
only with LU8SSMD
Screw-in depths for
calculating the total tie-rod
lengths
Pressure setting
for priority side
Pressure setting
for priority side
100-P-0000047-E-12/10.2024
L.8S directional valves
25/79
4.6 Intermediate section with proportional
pressure reducing valve
4.6.1 Description
The 3-way pressure reducing valve holds the pressure at
the actuator port at a constant level, as set by the solenoid
current. Via the LS-feedback, this function can work with all
pressure compensators and pump systems.
The relevant additional functions are described below.
4.6.2 Functions
LU8SPDRZ*-06AS.-..
3-way pressure reducing valve, minimum actuator
pressure 8 … 20 bar.
LU8SPDRZ*-06BS.-..
3-way pressure reducing valve, minimum actuator
pressure 8 … 20 bar, has a seat valve for leak-free shut-
off of the load.
4.6.3 Technical data
General characteristics Unit Description, value
Primary pressure P
max
bar max. 300
Secondary pressure P
Red
(as per pressure range) bar 40, 100, 160, 250
Nominal flow rate Q
max
l/min 40 for LU8SPDRZ*-06BS.-.. / 25 for LU8SPDRZ*-06CS
Port thread DIN 3852 - M18 x 1,5 / M22 x 1,5
Power consumption: pressure reducing valve
solenoid x
Watt
20
27
Nominal voltage pressure reducing valve V DC 12 (24 on enquiry)
Plug type DIN 43650
Solenoid current I
min
I
max
A
0,25 or 0,13 10%
1,90 or 0,95 10%
Enclosure protection AMP: IP65 DT: IP67 (DIN EN 60529)
Connector socket DIN 43650
4.6.4 Performance graphs
4.6.4.1 Control characteristic P
reduced
= f ( I
solenoid
)
100
0
Red. Pressure as % of the
adjustment ranges
1,90 10% =12V
Solenoid current I (A)
1,0
0
75
50
25
10
0,5 1,5
Linearity deviation 10%
4.6.4.2 Adjustment ranges 3-way pressure control
valve
250
30
0
0
160
100
Solenoid current I [A]
15-160 bar
12-100 bar
1,90 +10% =12V
0,5 1,0 1,5
100
200
150
50
P [bar]
Pressure range 6
Pressure range 4
4.6.4.3 Control characteristic as a function of the
flow rate
250
200
150
50
0
30 10 10 30
red. pressure [bar]
40 20 0 20 40
Q [l/min]
100
50 50
P-P
R
P
R
-
T
300
100-P-0000047-E-12/10.2024
L.8S directional valves
26/79
4.6.5 Overview of sections
Symbol Description Part number
PTLS
PTLS
A
LU8SPDRZ*-06AS4-1M22J12*01 100040972
solenoid operated
pressure range 12 … 100 bar
port threads to DIN 3852 M22 x 1,5
PTLS
PTLS
A
LU8SPDRZ*-06AS6-1M22J12*01 100042074
solenoid operated
pressure range 15 … 160 bar
port threads to DIN 3852 M22 x 1,5
4.6.6 Connector socket
AMP Junior Timer
J
DT04-2P-EP04
T
4.6.7 Dimension
70
101
208
36.5
153
118
85
60
23
M22x1.5
Nur bei LU8SPDRZ*-06BS
100-P-0000047-E-12/10.2024
L.8S directional valves
27/79
5 Directional valves
5.1 LA8S-/ LF8S- Directional valves
5.1.1 Description
These directional valve sections, operated by hand lever or
remote cable, are distinguished by their adaptability.
Auxiliary functions can be bolted on above the valve. To
enable this, the appropriated interfaces must be chosen
(see the following illustrations).
5.1.1.1 Integral auxiliary functions
Individual pressure compensator
The integral 2-way pressure compensator maintains a
constant pressure differential over the metering orifice in
the directional valve spool. This means that the corres
ponding actuator flow remains constant and load-inde
pendent even if another actuator that needs a higher
pressure is operated at the same time.
Flow cut-off
Thanks to the adjustable maximum pressure, the actuat
or flow rate is reduced to zero when the level is exceeded.
The corresponding function therefore stops until the actu
ator pressure has fallen to the permissible pressure
range.
5.1.2 Function
5.1.2.1 LA8S
Operatet by hand lever
5.1.2.2 LA8S
Operated by remote cable
5.1.3 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Actuator pressure duty cycle = 10 s/min bar max. 315
Spool size l/min 10, 16, 25, 40, 60
1)
Operating force on the spool N 170 … 210
1) Higher flow rates on enquiry.
5.1.4 Overview of sections
Symbol Description Part number
LSTP
LSTP
A
B
L.8SE……-.*O-…. see ordering code
port thread for actuator A and B
LSTP
LSTP
A
B
Zusatzventil
L.8SE……-.MO-…. see ordering code
for bolt-on auxiliary valves on flange face O
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L.8S directional valves
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LSTP
LSTP
A
B
L.8SM……-.*I-…. see ordering code
with port thread for actuator A and B
integrated pressure compensator
LSTP
LSTP
A
B
Zusatzventil
L.8SM……-.MI-…. see ordering code
for bolt-on auxiliary valves on flange face O
integrated pressure compensator
A
B
a
b
L.8SM……-F*L-…. see ordering code
with port thread for actuator A and B
spring return, flow cut-off
integrated pressure compensator
A
B
a
b
Zusatzventil
L.8SM……-FML-…. see ordering code
for bolt-on auxiliary valves on flange face O
spring return, flow cut-off
integrated pressure compensator
5.1.5 Performance graphs
5.1.5.1 Maximum flow rate at directional valve
(without compensator), LS-function
40
20
0
8 10 121416 18
Δp P -> LS [bar]
100
60
20 22 24 26 28
30
60
40
25
16
10
80
Ver
[]
Spool size
120
140
Actuator flow rate Q [l/min]
5.1.5.2 Flow characteristic with individual pressure
compensator at flange face U
Spool stroke S [mm]
Actuator flow rate Q [l/min]
Spool size
70
50
40
30
20
10
0
60
60
1234560
80
90
25
40
10
16
5.1.5.3 Pressure drop A/B " T
20
16
12
8
4
0
02040
Inlet flow Q
In
[l/min]
60 80 100 120
A/B -> T [bar]
LA8S/LF8S
A/D spool in
switched position
24
5.1.5.4 Pressure drop P -> A/B (L.8S-directional
valve), without pressure compensator,
spool at maximum stroke
Inlet flow Q
In
[l/min]
P -> A/B [bar]
10 2516
20
16
12
8
4
0
0 102030 4050 607080
24
40
60
Spool size
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L.8S directional valves
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5.1.6 Overview spool position control
The purpose of the spool position controls and their variants
is to optimise the spool-operation logic, and they should be
employed to make the user's task simpler. The various
types are described below.
Spool position control
type
Spring return from
switch position
Detent function in switch position
Friction detent in
switch position
1 2 1 2 3 1 2
2 0 1
A
2 0 1
B
2 0 1
C
2 0 1
D
0 1
E
2 0 1
F
0 1
G
0 1
J
3 2 0 1
L
3 2 0 1
M
2 0 1
R
3 2 0 1
T
3 2 0 1
U
Spring return: The spool returns to position 0 automatically.
Detent function: The spool is held at position 0; at maximum stroke it is also held in the respective position.
Friction detent: A detent hold can be felt at position 0; at any other position a friction device restrains the spool.
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L.8S directional valves
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5.1.7 Option menu for ordering code (ordering code see section 5.1.8)
A
PT
0
1
A
PT
0
1
Attachment to flange face O
port threads for line connections = *
flange face for auxiliary valve = M
PT
AB
012
PT
AB
4K
0123
PT
AB
012
4A
Operation
load-independent individual operation = E
load-independent parallel operation = M
4D
3I
3J
Control type
hand lever = LA8S
remote cable = LF8S
10 l/min
16 l/min
25 l/min
40 l/min
60 l/min
10 l/min
16 l/min
25 l/min
40 l/min
60 l/min
Spool type (way function, spool function, spool size in l/min)
Compensator function:
without pressure compensator = O
with integrated pressure compensator = I
with pressure compensator and flow cut-off = L
with flow limiter (SDR) = D
Type of connection at face O
Flange face to factory standard = ***
Line connection at ports A and B:
Ex. DIN 3852 - M18 x 1.5 = M18
M22 x1,5 = M22
G½“ = B12
5.1.8 Dimensions
5.1.8.1 Switch positions LF8S
3
2
0
1
10
6
6
5.1.8.2 LF8S-directional valve
9,7
84,2
48
28,7
20,1
M x105
81,781,7
with flange face for auxiliary valve
with port threads for line connections
25
11,5
H88
15
19
M x1,518 M x1,518
117
30
78
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L.8S directional valves
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5.1.8.3 LF8S-directional valve with integrated pressure compensator
2511,5
48
H88
15
20,1
28,7
M x105
19
M x1,518 M x1,518
117
30
78
104,5
107
with flange face for auxiliary valve
with port threads for line connections
5.1.8.4 LA8S-directional valve
9,7
48
28,7
20,1
M x105
81,781,7
44
11,5
M x1,518 M x1,518
117
30
78
ca. 250
31
1
0
2
3
84,2
with flange face for auxiliary valve
with port threads for line connections
5.1.8.5 LA8S-directional valve with integrated pressure compensator
M x1,518 M x1,518
107
117
30
78
195,1
44
11,5
32,5
ca. 250
48
31
1
0
2
3
221,5
104,5
with flange face for auxiliary valve
with port threads
for line connections
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L.8S directional valves
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5.1.8.6 LA8S-directional valve with integrated pressure compensator and flow cut-off
M x1,518 M x1,518
107
117
30
78
195,1
44
11,5
32,5
ca. 250
48
31
1
0
2
3
221,5
104,5
with flange face for auxiliary valve
with port threads
for line connections
5.1.9 Ordering code LA8S… / LF8S…
Hand lever = LA8S
Remote operation = LF8S
1)
Load-independent individual operation = E
Load-independent parallel operation = M
3-way function = 3
4-way function = 4
Spool function = A, D, I, J, K
Port A spool code: 10, 16, 25, 40, 60
2
) = e.g. 10
Port B spool code: with 3-way function = **
with 4-way function 10,16,25,40,60
2)
= e.g. 10
1)
Spool position control (overview see section 5.1.5) = e.g. A
Attachment to flange face O port threads for line connection = *
flange face for auxiliary valves = M
Compensator function: without pressure compensator = O
with integrated pressure compensator = I
with pressure compensator and flow cut-off = L
with flow limiter (SDR) = D
Design stage (to be inserted by Bucher Hydraulics)
Type of connection at face O: flange face to factory standard = ***
line connection to port A and B: DIN 3852 - M18 x 1,5 = M18
DIN 3852 - M22 x 1,5 = M22
DIN 3852 - G½” = B12
Option (to be inserted by Bucher Hydraulics)
E
White fields = data specified by Bucher Hydraulics
Grey fields = fill out the fields according the option menu 5.1.6 and the spool position overview 5.1.7
*
-LA8S 4 A 1010 F *
O
- 1 M18
1) When fitting the cable actuator 200.9609.0003.0, the special version LF8S...*17 must be selected.
2) For higher flow rates, please enquire.
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L.8S directional valves
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5.2 LD8S-/ LC8S- Directional valves
5.2.1 Description
These directional valve sections with direct-acting ON/OFF
solenoid or proportional solenoid are distinguished by their
adaptability. Auxiliary functions can be bolted on above or
below the valve. To enable this, the appropriate interfaces
must be chosen (see following illustrations).
It is possible to set either the opening point of the control
spool, or any predetermined point on the characteristic.
In the version with an additional manual operator, the flow
rate can be increased.
The setting of the additional manual operator has no effect
on the electrical operation. During electrical operation, the
additional manual operator is not carried along with the sole
noid mechanism. The lever remains in its neutral position,
and thus has no influence on the spool characteristic.
5.2.1.1 Integral auxiliary functions
Individual pressure compensator
The integral 2-way pressure compensator maintains a
constant pressure differential over the metering orifice in
the directional valve spool. This means that the corres
ponding actuator flow remains constant and load-inde
pendent even if another actuator that needs a higher
pressure is operated at the same time.
Flow cut-off
Thanks to the adjustable maximum pressure, the actuat
or flow rate is reduced to zero when the level is exceeded.
The corresponding function therefore stops until the actu
ator pressure has fallen to the permissible pressure
range.
The pressure adjustment is manual, or optionally electro
proportional.
3-way pressure control
Both a 3-way pressure control (P constant) and a flow
control (Q constant) are incorporated in this valve section.
The integral pressure control function can be switched to
actuator port A or B, depending on the switching position
of the valve section.
Below the pressure setting, the pressure-control as
sembly works as an individual pressure compensator and
maintains a constant pressure differential over the meter
ing orifice in the directional valve spool.
This means that the actuator flow rate is load-independ
ent. For optimum 3-way pressure control, the correspond
ing directional function must be activated to its maximum
extent.
Typical applications are actuating functions that are spe
cifically speed-controlled, with the possibility of a holding
or press function. This function can be controlled to any
required pressure and can act optionally on either actuat
or A or B.
5.2.2 Function
5.2.2.1 LD8S
with direct-acting ON/OFF solenoid
5.2.2.2 LD8S
with direct-acting ON/OFF solenoid,
optional manual override for the valve
spool
The flow rates to the A and B actuator ports are graded by
spool size as per sections 5.2.4. Using the stop-screw on
the non-active solenoid, each flow rate can be reduced from
its maximum by a maximum of 50%.
5.2.2.3 LC8S
with direct-acting proportional solenoid
5.2.2.4 LC8S
with direct-acting proportional solenoid,
optional manual override for the valve
spool
The flow rates to the A and B actuator ports are graded by
spool size as per sections 5.2.4.
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L.8S directional valves
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5.2.3 Technical data
General characteristics Unit Description, value
LD8S LC8S
Type of operation ON/OFF Proportional
Inlet pressure bar 250
Actuator pressure (duty cycle 10 sec/min) bar max. 280
Spool size l/min 02, 05, 10, 16, 25, 40, 60
Solenoid design ON/OFF solenoid with
mechanical manual override
Proportional solenoid with
mechanical manual override
Nominal voltage V DC 12 (10,8 …14)
24 (21,6 …28)
12 or 24
Power consumption at R
20
Watt 22 (U
N
12 V)
22 (U
N
24 V)
max. 24 at 2,5 A (U
N
12 V)
max. 24 at 1,3 A (U
N
24 V)
Duty cycle % 100 100 at Imax 2,5 A (U
N
12 V)
1,3 A (U
N
24 V)
Plug type AMP Junior Timer with protective diode P6KE33CA,
DT04-2P-EP04
Enclosure protection AMP: IP65 DT: IP67 (DIN EN 60529)
Switch frequency Hz > 2 (please contact the factory)
Accessories For electronic controls see overview brochure 100-P-700069
IMPORTANT: Maximum reduction is to 50% of the respective nominal spool size.
5.2.4 Performance graphs
5.2.4.1 Typical flow characteristic curve without
compensator function (spool type 4D/4A to
loop line A->B / B->A)
(Inlet section with 3-way press. compensator for p 12 bar)
I [A]
2,10,7
10
20
0
0,5 0,9 1,1 1,3 1,5 1,7 1,9 2,3 2,5
30
40
50
10
60
16
25
40
60
02
05
70
1,050,25
0,45
0,65
0,85 1,25
12 Volt
24 Volt
Actuator flow rate Q [l/min]
Spool size
5.2.4.2 Typical flow characteristic curve with com
pensator function (spool type 4D/4A to
loop line A->B / B->A)
02
10
20
0
30
40
50
10
60
16
40
60
05
25
2,1
0,7
0,5
0,9
1,1
1,3
1,5
1,7 1,9
2,3
2,5
1,050,25 0,45
0,65
0,85 1,25
12 Volt
24 Volt
I [A]
70
Actuator flow rate Q [l/min]
Spool size
5.2.4.3 LD / LC
Maximum flow rate at the directional valve
without compensator function,
LS-function
05
02
10 15 20 25
Dp [bar] P-LS
Actuator flow rate Q [l/min]
30 355
20
40
60
80
Spool size
0
0
40
25
16
10
60
5.2.4.4 LC
Pressure drop A/B -> T in the LC8SM4A
directional stage
20 30 40 50
Dp (bar) A/B-T
Q (l/min)
60 70 8010
10
20
30
40
0
0
40
16
10
25
502
100
60
Spool size
100-P-0000047-E-12/10.2024
L.8S directional valves
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5.2.4.5 Typical flow characteristic curve with flow
cut-off function, pressure relief adjustable
(manual)
30
10
40
20
50
10050 200 250150
0
0
60
Actuator flow rate Q [l/min]
P -> T [bar]
5.2.4.6 Typical flow characteristic curve with flow
cut-off function, pressure relief adjustable
(electroproportional)
30
10
40
20
50
10050 200 250150
0
0
60
P -> T [bar]
Actuator flow rate Q [l/min]
5.2.4.7 LC flow cut-off function
pressure setting p - I (electr. prop.)
150
50
200
100
250
200 1000600 800400
p [bar]
0
0 1200 1400
Solenoid current I [mA]
5.2.4.8 Typical pressure profile
3-way pressure control
Electroproportional
120
40
160
80
200
0,40,2 0,8 1,00,6 I (A)
p A/B [bar]
0
0
240
280
Pressure range [bar]
1,2 1,4
250
160
100
Inverse function possible – please enquire.
5.2.4.9 Typical pressure profile
3-way pressure control
Overall function
120
40
160
80
200
-30-40 -10 20-20 QA/B [l/min]
p A/B [bar]
0
-50
240
280
30 50
100
40
5.2.5 Overview of sections
5.2.5.1 LD8S / LC8S-directional valves with port threads
Symbol Description Part number
LSTP
LSTP
A
B
L.8SE……-.*O-…. see ordering code
port threads for actuator A and B
LSTP
LSTP
A
B
L.8SM……-.*I-…. see ordering code
port threads for actuator A and B
pressure compensator
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L.8S directional valves
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LST
P
LSTP
A
B
L.8SM……-.*L-…. see ordering code
port threads for actuator A and B
flow cut-off
A
B
LS
T
P
LST
P
L.8SM……-.*P-…. see ordering code
port threads for actuator A and B
pressure compensator
flow cut-off electroproportional
A
B
a
b
TP
TP
LS
LS
L.8SM……-..4-…. see ordering code
port threads for actuator A and B
pressure compensator
3-way pressure control
5.2.5.2 LD8S / LC8S-directional valves for bolt-on auxiliary valves
Symbol Description Part number
LSTP
LSTP
A
B
Aux. valve
L.8SE……-.MO-…. see ordering code
for bolt-on auxiliary valves on flange face O
LSTP
LSTP
A
B
Aux. valve
L.8SM……-.MI-…. see ordering code
for bolt-on auxiliary valves on flange face O
flow cut-off
LST
P
LSTP
A
B
Aux. valve
L.8SM……-.ML-…. see ordering code
for bolt-on auxiliary valves on flange face O
pressure compensator
flow cut-off
A
B
LS
T
P
LST
P
Aux. valve
L.8SM……-.MP-…. see ordering code
for bolt-on auxiliary valves on flange face O
integrated individual pressure compensator
flow cut-off, electroproportional
A
B
a
b
Aux. valve
TP
TP
LS
LS
L.8SM……-.M4-…. see ordering code
for bolt-on auxiliary valves on flange face O
pressure compensator
3-way pressure control
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L.8S directional valves
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5.2.6 Option menu for ordering code (ordering code see section. 5.2.9)
Nominal voltage
12 V DC = 12
24 V DC = 24
Attachment to flange face O
port threads for line connections = *
flange face for auxiliary valve = M
Operation
load-independent individual operation = E
load-independent parallel operation = M
without pressure compensator = O
Compensator function: with flow limiter (SDR) = D
with pressure compensator = I
with pressure compensator and flow cut-off = L
with pressure compensator, electroproportional flow cut-off = P
with pressure compensator, electrically-ON/OFF flow cut-off = M
with pressure compensator and 3-way pressure control = 1
1 = up to 40 bar / 2 = up to 100 bar / 3 = up to 160 bar /
4 = up to 250 bar
4A
012
PT
AB
4D
012
PT
AB
Additional operator
spool stroke limiter (only LD8S) = S
manual override = N
additional manual operator = W
Control type
ON/OFF solenoid = LD8S
proportional solenoid = LC8S
Type of connection at face O
flange face to factory standard = ***
line connection to port A and B: DIN 3852 - M18x1,5 = M18
M22x1,5 = M22
G½” = B12
Connector socket
AMP Junior Timer = J
Deutsch plug DT04-2P-EP04 = T
02 l/min
05 l/min
10 l/min
16 l/min
25 l/min
40 l/min
60 l/min
Spool type (way function, spool function, spool size in l/min)
A
PT
3A
012
10 l/min
16 l/min
25 l/min
40 l/min
60 l/min
A
PT
3I
01
05 l/min
10 l/min
16 l/min
25 l/min
40 l/min
60 l/min
3J
01
A
PT
4F
012
PT
AB
4E
012
PT
AB
16 l/min
25 l/min
40 l/min
60 l/min
10 l/min
16 l/min
25 l/min
40 l/min
60 l/min
5.2.7 Connector socket
AMP Junior Timer with protective diode P6KE33CA
J
DT04-2P-EP04
T
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L.8S directional valves
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5.2.8 Dimensions
5.2.8.1 LD8S / LC8S core tube
LD8S
91.4
89.7
LC8S
5.2.8.2 LD8S / LC8S-directional valve
48
81,7
with port threads
with flange face for
auxiliary valve
14.5
9.7
84.2
33
81
121.6
solenoid b
solenoid a
M18x1,5
M18x1,5
LD8S= 304,8 / LC8S= 301,4
LD8S= 91,4 / LC8S = 89,7
5.2.8.3 LD8SM / LC8SM-directional valve with integrated pressure compensator
M x1.518
M
x1.5
18
48
121,7
33
81
107
32,4
14,5
solenoid a
104,5
LD8SM= 91,4 / LC8SM= 89,7
LD8SM= 304,8 / LC8SM= 301,4
solenoid b
with port threads with flange face for
auxiliary valve
5.2.8.4 LD8S / LC8S-directional valve with integrated pressure compensator and flow cut-off
48
solenoid b
solenoid a
104,5
14,5
32,4
107
33
81
121,6
M x1.518
M
x1.5
18
LD8S= 304,8 / LC8S= 301,4
LD8S= 91,4 / LC8S = 89,7
with port threads
with flange face for
auxiliary valve
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L.8S directional valves
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5.2.8.5 LD8S / LC8S-directional valve with manual override
LD8S = 381,2 / LC8S = 377,8
LD8S = 171,2 / LC8S = 169,5
118.1
29.5
77.5
84.2
131.4
48
51.8
M18x1,5
M18x1,5
solenoid b
solenoid a
81,7
14,5
9.7
Switched position
2
0
1
with port threads
with flange face for
auxiliary valve
5.2.8.6 LD8S / LC8S-directional valve with manual override, pressure compensator and flow cut-off
154,2
118,1
48
51,8
29,5
77,5
M18x1,5
M18x1,5
solenoid b solenoid a
104,5
107
14,5
32,4
LD8S = 381,2 / LC8S = 377,8
LD8S = 171,2 / LC8S = 169,5
LD8S with flange face for
auxiliary valve
flow cut-off only for L.8SM…-..L-…
with port threads
with flange face for
auxiliary valve
5.2.8.7 LD8S / LC8S-directional valve with pressure compensator, electrically-proportionally flow cut-off
14,5
32,4
107
33
81
121,6 LD8S/LC8S = 146,1
LD8S = 359,6 / LC8S = 357,9
104,5
48
M18x1,5
M18x1,5
with port threads
with flange face for
auxiliary valve
solenoid b
solenoid a
5.2.8.8 LD8S / LC8S-directionalvalve with pressure compensator and 3-way pressure control
48
with port threads
With flange face for
auxiliary valve
104,5
LD8S = / LC8S = 325
326.7
121.6
33
81
14.5
107
32.4
M x1,5
18
M x1,518
113.2
solenoid
solenoid
a
b
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L.8S directional valves
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5.2.9 Ordering code
ON/OFF solenoid = LD8S
Proportional solenoid = LC8S
Load-independent individual operation = E
Load-independent parallel operation = M
3-way function = 3
4-way function = 4
Spool function = A, D, E, F, I, J,
Port A spool code
02, 05, 10, 16, 25, 40. 60 = e.g. 10
Port B spool code: for 3-way function = **
for 4-way function 02, 05, 10,16,25,40,60 = e.g.10
Additional operator: without add. manual override (only for LC8S) = *
with spool stroke limiter (only for LD8S) = S
with additional manual override = N
with manual override = W
Attachment to flange face O: port threads for line connection = *
flange face for auxiliary valve = M
without preassure compensator = O
Compensator function: with flow limiter (SDR) = D
with integrated pressure compensator = I
with pressure compensator and flow cut-off = L
with pressure compensator, electrically-proportionally flow cut-off = P
with pressure compensator, electrically-ON/OFF flow cut-off = M
with pressure compensator, 3-way press. control (only up to 40 l/min) = e.g. 2
Information for pressure setting: 1=up to 40 bar / 2=up to 100 bar / 3=up to 160 bar / 4=up to 250 bar
Design stage (will be inserted by Bucher Hydraulics)
Type of connection at face O: flange face to factory standard = ***
line connection to port A and B: DIN 3852: M18 x 1,5 = M18
M22x1,5 = M22
G½” = B12
Connector socket: AMP Junior Timer =J
Deutsch plug DT04-2P-EP04 =T
Nominal voltage: 12 V DC =12
24 V DC =24
Coating without corrosion protection = *
Zn/Ni coating = Z
Option: HPCO/Pressure Beyond for compatibility with 2/2 double-seat valve SVH04 (see chapter 10) = 02
E
White fields = data specified by Bucher Hydraulics
Grey fields = fill out the fields according the option menu 5.2.6
-L
D8S
3 A 10 ** S *
O
-
1 M
18
J 12
*
5.2.10 Connector socket
J = AMP Junior Timer with protective diode P6KE33CA T = Deutsch plug DT04-2P-EP04
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L.8S directional valves
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5.3 LM8S-/ LP8S- Directional valves
5.3.1 Description
These directional valve sections, with two-stage solenoid/
hydraulic control, ON/OFF or proportional, are distin
guished by their slim design and their adaptability. Auxiliary
functions can be bolted on above or below the valve. To en
able this, the appropriate interfaces must be chosen (see
the following illustrations).
Manual overrides are available that act on the pilot stage, or
directly on the main stage (non-following type). End-stops
for the spool (special feature L.8S…/16) make it possible to
limit the maximum actuator flow to any desired value.
5.3.2 Function
5.3.2.1 LM8S with ON/OFF solenoid, two-stage 5.3.2.2 LM8S with ON/OFF solenoid, two-stage
optional manual override for the valve
spool
5.3.2.3 LP8S with proportional solenoid, two-stage 5.3.2.4 LP8S with proportional solenoid, two-stage
optional manual override for the valve
spool
5.3.3 Technical data
General characteristics Unit Description, value
LM8S LP8S
Type of operation ON/OFF Proportional
Inlet pressure bar 300
Actuator pressure (10 sec/min) bar max. 315
Spool size l/min 10, 16, 25, 40, 63, 75
1)
Solenoid design ON/OFF solenoid with
mechanical manual override
Proportional solenoid with
mechanical manual override
Nominal voltage V DC 12 V (10,8 …14)
24 V (21,6 …28)
12 or 24
Power consumption Watt 24 12 or 24
Plug type AMP Junior Timer, Deutsch plug DT04-2P-EP04
Switch frequency Hz > 2 (please contact the factory)
Duty cycle % 100 100 with Imax 1,6 A (U
N
12 V)
0,8 A (U
N
24 V)
Enclosure protection AMP: IP65 DT04-2P: IP67 (DIN EN 60529)
Accessories Joystick brochure 100-P-700071
1) 75 l/min only available for spool types 4D and 3J. Higher flow rates on enquiry.
IMPORTANT! If the maximum nominal voltage is exceeded, the solenoid can be damaged.
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L.8S directional valves
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5.3.4 Performance graphs
5.3.4.1 Maximum flow rate at directional valve
(without compensator), LS-function
40
20
0
81012141618
Δp
P
->
LS
[bar]
100
60
20 22 24 26 28 30
63
40
25
16
10
80
120
75
Actuator flow rate Q
Act
[l/min]
Spool size
140
5.3.4.2 Pressure drop A/B -> T
(L.8S-directional valve)
20
16
12
8
4
0
02040
Inlet flow Q
In
[l/min]
60 80 100 120
A/B -> T [bar]
24
A-D spool in
switched position
D spool in neutral position
5.3.4.3 Pressure drop P " A/B (L.8S-directional
valve), spool at max. switched position
20
16
12
8
4
0
0 102030 4050
Inlet flow Q
In
[l/min]
60 70 80
90
P -> A/B [bar]
24
10
75
63402516
5.3.4.4 Control characteristic (LP8SM..)
loop line (A->B / B->A)
63
40
25
16
10
60
40
20
0
0,7 0,8 0,9 1 1,1 1,2 1,3 1,4 1,5 1,6 1,7
Solenoid current l [A]
12V
0,4 0,5 0,6 0,7 0,8 24V
80
75
Q [l/min]
100
Spool size
5.3.5 Overview of sections
5.3.5.1 LM8S / LP8S-directional valve with port threads
Symbol Description Part number
LSTP
LSTP
A
B
L.8SE……-.**-…. see ordering code
port threads for actuator A and B
5.3.5.2 LM8S / LP8S-directional valve for bolt-on auxiliary valve
Symbol Description Part number
LSTP
LSTP
A
B
Aux. valve
L.8SE……-.M*-…. see ordering code
for bolt-on auxiliary valves on flange face O
LSTP
LSTP
A
B
Aux. valve
L.8SM……-.*K-…. see ordering code
for bolt-on auxiliary valves on flange face U
LSTP
LSTP
A
B
Aux. valve
Aux. valve
L.8SM……-.MK-…. see ordering code
for bolt-on auxiliary valves on flange faces O and U
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L.8S directional valves
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5.3.6 Option menu for ordering code (ordering code see section 5.3.9)
Attachment to flange face O
port threads for line connection = *
flange face for auxiliary valve = M
Operation
Load-independent individual operation = E
load-independent parallel operation = M
Additional operator
without additional operator = *
manual override (with lever) = N
manual override (with rotary knob)
(only operative in switch position 1) = S
Control types
ON/OFF solenoid = LM8S
proportional solenoid = LP8S
Attachment to flange face U
without (valve type E) = *
with (valve type M) = K
Connector socket
AMP Junior Timer = J
Deutsch plug DT04-2P-EP04 = T
Type of connection at face O
flange face to factory standard = ***
line connection to port A and B:
DIN 3852-M18 x 1.5 = M18
DIN 3852-M22 x 1.5 = M22
Nominal voltage
12 V DC = 12
24 V DC = 24
10 l/min
16 l/min
25 l/min
40 l/min
63 l/min
75 l/min
05 05 l/min
10 10 l/min
16 16 l/min
25 25 l/min
40 40 l/min
63 63 l/min
10 l/min
16 l/min
25 l/min
40 l/min
63 l/min
Spool type (way function, spool function, spool size in l/min)
05 05 l/min
10 10 l/min
16 16 l/min
25 25 l/min
40 40 l/min
63 63 l/min
75 75 l/min
10 10 l/min
40 40 l/min
63 63 l/min
16 16 l/min
40 40 l/min
63 63 l/min
A
PT
3A
012
A
PT
3I
01
4D
012
PT
AB
4F
012
PT
AB
4E
012
PT
AB
3J
01
A
PT
4A
012
PT
ABA
PT
3A
5.3.7 Connector socket
AMP Junior Timer
J
Deutsch plug DT04-2P-EP04
T
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L.8S directional valves
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5.3.8 Dimensions
5.3.8.1 LM8S-/ LP8S-directional valve with port threads
37,5
48
18,5
M18x1,5 M18x1,5
37
72,5
307,5
31
41
102
Air-bleed point
Solenoid energised
gives switch position 2
Air-bleed point
Solenoid energised
gives switch position 1
solenoid b solenoid a
5.3.8.2 LM8S-/ LP8S-directional valve with facility for bolt-on auxiliary valves
70
28
37,5
solenoid b
solenoid a
Flange face O
Flange face U
5.3.8.3 LM8S-/ LP8S-directional valve (spool types 3I and 3J)
37.5
252.5
Magnet a
5.3.8.4 Manual override with rotary knob (L.8S......-S..)
Manual spool operation with
flow setting via rotary knob for
actuator port A
Only operative in switch position 1.
1) types 3I and 3J
2) types 3A, 4A, 4D, 4E and 4F
31
37
65
82
1)
2)
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L.8S directional valves
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5.3.8.5 Manual override with lever (L.8S......-N..)
2
0
1
17
167
37
54
31
111
Air-bleed point
Switch position
5.3.8.6 Spool stroke limiter (L.8S.../16)
211,5
69
End-stop for
End-stop for
switch position 1
switch position 2
5.3.8.7 Manual override with lever and spool stroke limiter (L.8S......-N.../16)
17
2
0
1
167
37
54
111
Switch position
End-stop for
switch position 2
End-stop for
switch position 1
Air-bleed point
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L.8S directional valves
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5.3.9 Ordering code
ON/OFF solenoid = LM8S
Proportional solenoid = LP8S
Load-independent individual operation = E
Load-independent parallel operation = M
3-way function = 3
4-way function = 4
Spool function
A, D, E, F, I, J = z. B. D
Port A spool code
10, 16, 25, 40, 63, 75
1)
= e.g. 10
Port B spool code
for 3-way valves = **
for 4-way valves:
10, 16, 25, 40, 63, 75
1)
= e.g. 10
Additional operator:
without (only for LC8S) = *
manual override (with lever) = N
manual override (with rotary knob) = S
Attachment to flange face O
port thread for line connection = *
flange face for auxiliary valve = M
Attachment to flange face U
without (for load-independent individual operation) = *
with (for load-independent parallel operation) = K
Design stage (to be inserted by Bucher Hydraulics)
Type of connection at face O
flange face to factory standard = ***
line connection to port A and B: DIN 3852 - M18 x 1,5 = M18
DIN 3852 - M22 x 1,5 = M22
2)
Connector socket
Deutsch plug DT04-2P-EP04 = T
AMP Junior Timer = J
Nominal voltage
DC 12 V = 12
DC 24 V = 24
Option
spool stroke limiter for A and B = 16
no non-return valve in P (>
63 l/min) = 22
2)
M
White fields = data specified by Bucher Hydraulics
Grey fields = fill out the fields according the option menu 5.3.6
*
-LM8S 4 D 1010 N M
K
- 1 *** J12
1) 75 l/min only for spool function 4D and 3J. Higher flow rates on enquiry.
2) P reduced to 250 bar.
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L.8S directional valves
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5.4 LH8S-Directional valves
5.4.1 Description
These directional valve sections, operated by a hydraulic pi
lot stage, are distinguished by their slim design and their
adaptability.
Auxiliary functions can be bolted on above or below the
valve. To enable this, the appropriate interfaces must be
chosen (see the following illustrations).
Various manual overrides and end-stops for the spool make
it possible to limit the maximum actuator flow to any desired
value.
5.4.2 Function
5.4.2.1 LH8S hydraulic operation 5.4.2.2 LH8S optional manual override for the
valve spool
5.4.3 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Actuator pressure (duty cycle 10 sec/min) bar max. 315
Spool size l/min 10, 16, 25, 40, 63, 75
1)
Pilot pressure bar max. 50
Pilot pressure over tank pressure bar 4 … 16 (other pilot pressures on enquiry)
1) 75 l/min only available for 4D and 3J spool types. Higher flow rates on enquiry.
5.4.4 Performance graphs
5.4.4.1 Maximum flow rate at directional valve
(without compensator), LS-function
40
20
0
8 101214 1618
Δp
P
->
LS [bar]
100
60
20 22 24 26 28 30
63
40
25
16
10
80
120
75
Actuator flow rate Q [l/min]
Spool size
140
5.4.4.2 Pressure drop A/B -> T
(L.8S-directional valve)
20
16
12
8
4
0
02040
Inlet flow Q
In
[l/min]
60 80 100 120
A/B -> T [bar]
A/D-spool in
switched position
D-spool in
neutral position
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L.8S directional valves
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5.4.4.3 Pressure drop P " A/B (L.8S-directional
valve) spool at max. switched position
20
16
12
8
4
0
0 10203040 50
Inlet flow Q
In
[l/min]
60 70 80
90
P -> A/B [bar]
24
63
25
75
40
16
10
5.4.4.4 Control characteristic
63
40
25
16
10
70
60
50
40
30
20
10
0
246 81012
14 16
Pilot pressure [bar]
80
75
Actuator flow rate Q [l/min]
90
5.4.5 Overview of sections
5.4.5.1 LH8SE-directional valve with port threads
Symbol Description Part number
LSTP
LSTP
A
B
LH8SE……-.**-…. see ordering code
port threads for actuator A and B
5.4.5.2 LH8SM-directional valves for bolt-on auxiliary valve
Symbol Description Part number
LSTP
LSTP
A
B
Aux. valve
LH8SM……-.*K-…. see ordering code
for bolt-on auxiliary valves on flange face U
LSTP
LSTP
A
B
Aux. valve
LH8SE……-.M*-…. see ordering code
for bolt-on auxiliary valves on flange face O
LSTP
LSTP
A
B
Aux. valve
Aux. valve
LH8SM……-.MK-…. see ordering code
for bolt-on auxiliary valves on flange faces O and U
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L.8S directional valves
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5.4.6 Option menu for ordering code (ordering code see section 5.4.8)
Attachment to flange face O
port threads for line connections = *
flange face for auxiliary valve = M
Operation
load-independent individual operation = E
load-independent parallel operation = M
Additional operation
without = *
manual override (with lever) = N
Attachment to flange face U
without (valve type E) = *
with (valve type M) = K
Type of connection at face O
flange face to factory standard = ***
line connection to port A and B: DIN 3852-M18 x 1.5 = M18
DIN 3852-M22 x 1.5 = M22
Spool type (way function, spool function, spool size in l/min)
10 l/min
16 l/min
25 l/min
40 l/min
63 l/min
75 l/min
05 05 l/min
10 10 l/min
16 16 l/min
25 25 l/min
40 40 l/min
63 63 l/min
10 l/min
16 l/min
25 l/min
40 l/min
63 l/min
05 05 l/min
10 10 l/min
16 16 l/min
25 25 l/min
40 40 l/min
63 63 l/min
75 75 l/min
10 10 l/min
40 40 l/min
63 63 l/min
16 16 l/min
40 40 l/min
63 63 l/min
A
PT
3A
012
A
PT
3I
01
4D
012
PT
AB
4F
012
PT
AB
4E
012
PT
AB
3J
01
A
PT
4A
012
PT
AB
5.4.7 Dimensions
5.4.7.1 LH8S-directional valves (with port thread for actuator A and B)
37,5
48
18,5
M18x1,5
M18x1,5
37
164,5
39
G1/4”
41
31
39
102
G1/4”
Air-bleed point
Air-bleed point
Pilot control port for
switch position 2
Pilot control port for
switch position 1
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L.8S directional valves
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5.4.7.2 LH8S-directional valves (with flange face to bolt-on auxiliary valves)
70
28
37,5
Flange face O
Flange face U
5.4.7.3 Manual override for LH8S-directional valves (LH8S......-N..)
Air-bleed point
Switch position
2
0
1
17
167
31
37 54
111
5.4.7.4 Manual override for LH8S-directional valves and spool stroke limiter (LH8S......-N../16)
End-stop for
switch position 1
End-stop for
switch position 2
17
Air-bleed point
Switch position
2
0
1
167
37
54
111
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5.4.8 Ordering code
Hydraulic operation = LH8S
Load-independent individual operation = E
Load-independent parallel operation = M
3-way function = 3
4-way function = 4
Spool function
A, D, E, F, I, J = e.g. D
Port A spool code
10, 16, 25, 40, 63, 75
1)
= e.g. 25
Port B spool code
for 3-way function = **
for 4-way function 10, 16, 25, 40, 63, 75
1)
= e.g. 25
Additional operator
without = *
manual override (with lever) = N
Attachment to flange face O
port threads for line connection = *
flange face for auxiliary valve = M
Attachment to flange face U
without flange face U (for load-independent individual operation) = *
with flange face U (for load-independent parallel operation) = K
Design stage (to be inserted by Bucher Hydraulics)
Type of connection at face O
flange face to factory standard = ***
line connection to ports A and B: DIN 3852 - M18 x 1,5 = M18
DIN 3852 - M22 x 1,5 = M22
2)
Option Spool stroke limiting at A and B = 16
No check valve in P (from 63 l/min) = 22
2)
M
White fields = data specified by Bucher Hydraulics
Grey fields = fill out the fields according the option menu 5.4.6
*
-LH8S 4 D 2525 * *
K
- 1 M18
1) 75 l/min only for spool function 4D and 3J). Higher flow rates on enquiry.
2) P reduces to 250 bar.
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6 Auxiliary valves that bolt-on to the top flange face O
6.1 Anti-shock / make-up valves (secondary pressure relief)
6.1.1 Description
These bolt-on anti-shock/make-up valves are mounted on
flange face O. They protect the actuator from unacceptably-
high pressure peaks.
The excess pressure is discharged to tank. The integral
make-up function protects against cavitation. The following
combinations are available in the pressure ranges listed.
6.1.2 Technical data
General characteristics Unit Description, value
Pressure settings available
(measured at 4 l/min test flow)
bar 80, 100, 125, 140, 160, 175, 190, 210, 230, 250, 280,
300
Pressure drop through make-up valve bar 4 at 30 l/min
Port threads to DIN 3852 M18 x 1,5
6.1.3 Overview of sections
Symbol Description Part number
Directional
valve
A
B
LU8SPET-NVONVO-1M18*00 100015777
actuator port A and B: without pressure relief, with make-up valve
Directional
valve
A
B
LU8SPET-080080-0M18*00 100015727
actuator port A and B: with pressure relief p = 80 bar
with make-up valve
Directional
valve
A
B
LU8SPET-100100-0M18*00 100015655
actuator port A and: with pressure relief p = 100 bar
with make-up valve
Directional
valve
A
B
LU8SPET-125125-0M18*00 100015664
actuator port A and B: with pressure relief p = 125 bar
with make-up valve
Directional
valve
A
B
LU8SPET-140140-0M18*00 100015280
actuator port A and B: with pressure relief p = 140 bar
with make-up valve
Directional
valve
A
B
LU8SPET-160160-0M18*00 100015656
actuator port A and B: with pressure relief p = 160 bar
with make-up valve
Directional
valve
A
B
LU8SPET-175175-0M18*00 100018657
actuator port A and B: with pressure relief p = 175 bar
with make-up valve
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L.8S directional valves
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Directional
valve
A
B
LU8SPET-190190-0M18*00 100015665
actuator port A and B: with pressure relief p = 190 bar
with make-up valve
Directional
valve
A
B
LU8SPET-210210-0M18*00 100015615
actuator port A and B: with pressure relief p = 210 bar
with make-up valve
Directional
valve
A
B
LU8SPET-230230-0M18*00 100015666
actuator port A and B: with pressure relief p = 230 bar
with make-up valve
Directional
valve
A
B
LU8SPET-250250-0M18*00 100015657
actuator port A and B: with pressure relief p = 250 bar
with make-up valve
Directional
valve
A
B
LU8SPET-280280-0M18*00 100015658
actuator port A and B: with pressure relief p = 280 bar
with make-up valve
Directional
valve
A
B
LU8SPET-300300-0M18*00 100021038
actuator port A and B: with pressure relief p = 300 bar
with make-up valve
Others on enquiry.
6.1.4 Dimensions
50
25
M18x1,5
M18x1,5
107
39
36
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6.2 Check valves (pilot operated non return valves)
6.2.1 Description
These bolt-on load check valves with hydraulic or solenoid
operation shut off the actuator lines with zero leakage.
The valves must be mounted on flange face O of the direc
tional valve. The following variants are available.
6.2.2 Technical data
General characteristics Unit Description, value
LU8SPRH… LU8SPR1-… LU8SPR2-…
Function Hydraulic operated Solenoid operated Electrohydraulic
operated
Nominal flow rate l/min 63 30 70
Operating pressure bar max. 250 max. 210 max. 280
Actuator pressure bar max. 280 max. 250 max. 300
Port thread DIN 3852 - M18 x 1,5
Ratio of opening pressure to opposing
pressure for double-acting cylinders
1 : 6,25
1)
Pressure drop bar 7 at 63 l/min 10 at 30 l/min 10 at 63 l/min
Nominal voltage V DC 12 or 24
Power consumption Watt 27 22
Duty cycle % 100
Enclosure protection AMP Junior Timer: IP65
Deutsch plug DT04: IP67
(DIN EN 60529)
Connector socket Deutsch plug DT04-2P-EP04,
AMP Junior Timer
1) Others on enquiry.
6.2.3 Overview of sections
6.2.3.1 LU8SPRH-… (hydraulic operated, Q
max
= 63 l/min)
Symbol Description Part number
Directional
valve
A
B
LU8SPRH-DVADVB-0M18*00 100015612
actuator port A and B: with check valve
Directional
valve
A
B
LU8SPRH-DVA***-0M18*00 100015613
actuator port A: with check valve
actuator port B: without valve
Directional
valve
A
B
LU8SPRH-***DVB-0M18*00 100015614
actuator port A: without valve
actuator port B: with check valve
Others on enquiry.
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6.2.3.2 LU8SPR1-… (solenoid operation, Q
max
30 l/min)
Symbol Description Part number
Direction
al valve
A
B
LU8SPR1-DVADVB-0M18T12*00 100035157
actuator port A and B: with check valve
connector socket DT04-2P-EP04
nominal voltage 12 V DC
Directional
valve
A
B
LU8SPR1-DVADVB-0M18T24*00 100024626
actuator port A and B: with check valve
connector socket DT04-2P-EP04
nominal voltage 24 V DC
Others on enquiry.
6.2.3.3 LU8SPR2-… (solenoid operation, Q
max
70 l/min)
Symbol Description Part number
Direction
al valve
A
B
LU8SPR2-DVADVB-2M18T24*00 100040171
actuator port A and B: with check valve
connector socket DT04-2P-EP04
nominal voltage 24 V DC
Directional
valve A
B
LU8SPR2-DVA***-2M18T24*00 100040168
actuator port A: with check valve
actuator port B: without valve
connector socket DT04-2P-EP04
nominal voltage 24 V DC
Others on enquiry.
6.2.4 Connector socket
AMP Junior Timer
J
Deutsch plug DT04-2P-EP04
T
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L.8S directional valves
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6.2.5 Dimensions
6.2.5.1 LU8SPRH-…
48
M18x1,5
M18x1,5
143
30
65
36
BA
6.2.5.2 LU8SPR1-…
136
62
130
16
36
M x1,518
M x1,518
A
B
6.2.5.3 LU8SPR2-…
22
68
136
132
36
M x1,518
M x1,518
A
B
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L.8S directional valves
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6.3 Load check valves with anti-shock / make-up valves
(pilot operated non-return valve with pressure relief on the actuator side)
6.3.1 Description
These bolt-on load check valves with service line anti-
shock/make-up valves shut off the actuator lines with zero
leakage and protect the actuator from unacceptably-high
pressure peaks.
The valves must be mounted on flange face O of the direc
tional valve. The relevant pressure settings are detailed be
low.
Not usable for LA8S.. valves and LM8S../ LP8S.. valves
with emergency override.
6.3.2 Technical data
General characteristics Unit Description, value
Nominal flow rate l/min 70
Operating pressure bar max. 280
Actuator pressure bar max. 300
Pressure drop bar 10 at 63 l/min
Pressure settings available for the pressure relief
function (measured at 10l/min test flow)
bar 80, 100, 125, 140, 160, 175, 190, 210, 230, 250, 280,
300
Port threads M18 x 1,5 to DIN 3852
Nominal voltage V DC 12 or 24
Connector socket DT04-2P-EP04, AMP Junior Timer
Power consumption Watt 22
Duty cycle % 100
Enclosure protection % AMP: IP65 DT: IP67 (DIN EN 60529)
6.3.3 Overview of sections
6.3.3.1 LU8SPEC-…
Symbol Description Part number
A
B
LU8SPEC-300300-2M18J24*00 100040154
actuator port A and B: check valve p = 300 bar
flow cut-off
connector socket: AMP Junior Timer / nominal voltage 24 V DC
A
B
LU8SPEC-250250-2M18J24*15 100040156
actuator port A and B: check valve p = 250 bar
flow cut-off
Qmax = 30 l/min
connector socket: AMP Junior Timer / nominal voltage 24 V DC
A
B
LU8SPEC-250250-2M18G12*00 100041480
actuator port A and B: check valve p = 250 bar
flow cut-off
connector socket: GDM plug / nominal voltage 12 V DC
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L.8S directional valves
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A
B
LU8SPEC-280280-2M18J24*15 100040325
actuator port A and B: check valve p = 280 bar
flow cut-off
Qmax = 30 l/min
connector socket: AMP Junior Timer / nominal voltage 24 V DC
A
B
LU8SPEC-250250-2M18J12*15 100040913
actuator port A and B: check valve p = 250 bar
flow cut-off
Qmax = 30 l/min
connector socket: AMP Junior Timer / nominal voltage 12 V DC
Others on request.
6.3.4 Connector socket
AMP Junior Timer
J
DT04-2P-EP04
T
6.3.5 Dimensions
194
M x1,518
M
x1,5
18
143
25.5
319
78
36
A
B
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6.4 Load control valves
6.4.1 Description
These bolt-on load control valves with integral anti-shock
function ensure load-independent lowering motion at
speeds determined by the inlet flow. The load-control
valves close without leakage when the directional valve is
in its neutral position. The anti-shock valve setting should
preferably be 120% of the highest load pressure. Turning
the adjusting screw in the clockwise direction reduces the
setting, and this can also be used for emergency lowering
of the load.
The valves must be mounted on flange face O.
The following variants are available.
6.4.2 Function
6.4.2.1 LU8SPBH-***S. . .-...
Load-holding valve at port B, orifice damping facility in the
control line. Directional valve spool type 4F preferred.
6.4.2.2 LU8SPBH-S. . S. .-...
Load-holding valves at port A and B. Directional valve spool
type 4D preferred.
6.4.3 Technical data
General characteristics Unit Description, value
Port threads to DIN3852 M18 x 1,5
Pressure drop bar 25 at 63 l/min
Anti-shock valve adjustable bar 70 … 280
Standard pilot ratios bar 1,5:1 / 2,3:1 / 3:1
1)
1) For other pilot ratios, please enquire.
6.4.4 Overview of sections
Symbol Description Part number
Directional
valve
A
B
LU8SPBH-S15S15-0M18*00/PA=PB= see order details chapter 1.1
actuator port A and B: with load control, pilot ratio 1,5:1
Specify the pressure relief setting in bar
A
B
Directional
valve
T
LU8SPBH-***S15-0M18*00/PB= see order details chapter 1.1
actuator port A: without load-control
actuator port B: with load-control, pilot-ratio 1,5 : 1
Specify the pressure relief setting in bar
Directional
valve
A
B
LU8SPBH-E30E30-0M18*00/PA=PB= see order details chapter 1.1
actuator port A and B: with load-control, pilot-ratio 3:1
Specify the pressure relief setting in bar
A
B
Directional
valve
T
LU8SPBH-***E30-0M18*00/PB= see order details chapter 1.1
actuator port A: without load-control
actuator port B: with load-control, pilot-ratio 3:1
Specify the pressure relief setting in bar
Others on enquiry.
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6.4.5 Dimensions
6.4.5.1 LU8SSPBH-***S.. / LU8SSPBH-...S..
28
108
126
36
78
M18x1.5
M18x1.5
B
A
Only with
LU8SSPBH-...S..
6.4.5.2 LU8SSPBH-S..S..
Cannot be combined with manual override on LC8S / LD8S / LM8S / LP8S / LH8S; LA8S only when the lever pointing down.
108
160
36
78
16
16
M18x1.5
M18x1.5
B
A
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7 Auxiliary valves that bolt-on to the bottom flange face U
7.1 Individual pressure compensator
without / with flow cut-off
(torque-limiting)
7.1.1 Description
The individual pressure compensators (2-way compen
sators), which bolt-on to the bottom of the directional valve,
keep the p over the spool opening at a constant level, even
with high inlet pressures. This means that the actuator flow
remains constant and load- independent even if another ac
tuator that needs a higher pressure is operated at the same
time. There is an optional flow cut-off function at an ad
justable pressure, above which level the actuator flow goes
to zero. The valves must be mounted on flange face U of the
directional valve.
7.1.2 Technical data
General characteristics Unit Description, value
Operating pressure bar max. 300
Pressure for flow cut-off bar adjustable, 50 … 300
Nominal flow rate SKL / SKM
SKJ / SKH
l/min
max. 63
max. 75
7.1.3 Performance graphs
7.1.3.1 Maximum flow rate at directional valve
when using the LU8SSKL / SKM compen
sator in conjunction with an LU8SSCS inlet
section
40
20
0
02040
Inlet flow [l/min]
80
60
60
10
16
25
40
63
80 100 120
Actuator flow Q [l/min]
Spool size
751
1 Maximum flow rate at directional valve when
using the LU8SSKH / SKJ compensator in
conjunction with an LU8SSCS inlet section
7.1.3.2 Flow cut-off function of an LU8SSKM / SKJ
bottom-mounting plate
50
40
30
20
10
0
0 50 100
150
200 250
60
300
Dp
P
!
T
[bar]
Actuator flow Q [l/min]
70
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7.1.4 Overview of sections
Symbol Description Part number
Directional
valve
P
LS
P`
LU8SSKL-0*00 100015779
without flow cut-off
with no-drop function
nominal flow rate maximum. 63 l/min
Directional
valve
P
LS
P`
LU8SSKL-0*01 100013943
without flow cut-off
with no-drop function
damped model
nominal flow rate maximum 63 l/min
Directional
valve
P
LS
P`
T
LU8SSKM-0*00/P= see order details chapter 1.1
with flow cut-off
with no-drop function
nominal flow rate maximum 63 l/min
specify the pressure relief setting in bar
Directional
valve
P
LS
P`
LU8SSKH-0*00 100025901
without flow cut-off
without no-drop function
nominal flow rate maximum 75 l/min
Directional
valve
P
LS
P`
LU8SSKH-0*01 100027017
without flow cut-off
without no-drop function
damped model
nominal flow rate maximum 75 l/min
Directional
valve
P
LS
P`
T
<
LU8SSKJ-0*00/P= see order details chapter 1.1
with flow cut-off
without no-drop function
nominal flow rate maximum 75 l/min
specify the pressure relief setting in bar
Others on enquiry.
7.1.5 Dimensions
7.1.5.1 LU8SSKL / LU8SSKM
36
145
177
37
42
LU8SSKL
LU8SSKM
7.1.5.2 LU8SSKH / LU8SSKJ
36
182
45
LU8SSKJ
150 LU8SSKH
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7.2 Flow limiter without / with individual
pressure compensators
7.2.1 Description
This flow limiters, which bolt-on to the bottom of the direc
tional valve, are another metering orifice in addition to the
one in the spool in the directional valve. This means that the
usual flow rate, which is determined by the size of the spool,
can be reduced or limited to any desired level by means of
a small hand wheel.
Optionally, this function can be combined with an individual
pressure compensator for independent parallel operation,
and also with a flow cut-off function. The valves must be
mounted on flange face U of the directional valve.
This section can not be combined with the manual override
design on the LP8S / LM8S valves.
7.2.2 Technical data
General characteristics Unit Description, value
Operating pressure bar max. 300
Pressure for flow cut-off bar adjustable, 50 … 300
Nominal flow rate l/min max. 63
7.2.3 Performance graphs
7.2.3.1 Flow rate calibration LU8SSDR
50
40
30
20
10
0
012 45
Turns
60
6
10
16
25
40
63
78
Flow rate Q [l/min]
Spool size
80
3
7.2.3.2 Flow rate calibration LU8SSKR
50
40
30
20
10
0
01 234 5
Turns
60
6
10
16
25
40
63
78
Spool size
Flow rate Q (l/min)
80
7.2.3.3 Flow cut-off function in conjunction with an
LU8SSKS bottom-mounting section
50
40
30
20
10
0
0 50 100
150
200 250
60
300
Dp
P
!
T
[bar]
Flow rate Q [l/min]
80
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L.8S directional valves
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7.2.4 Overview of sections
Symbol Description Part number
Directional
valve
P
P'
LU8SSDR-0*00/Q= see order details chapter 1.1
with flow limiter
Directional
valve
P
P'
LS
LU8SSKR-0*00 100017752
with flow limiter
with 2-way compensator
Directional
valve
P
P`
LS
T
LU8SSKS-0*00/P= see order details chapter 1.1
with flow limiter
with 2-way compensator
with flow cut-off
7.2.5 Dimensions
7.2.5.1 LU8SSDR
36
182
18
42
7.2.5.2 LU8SSKR / SKS
only with LU8SSKS
36
203
18
70
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L.8S directional valves
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7.3 Pressure reducing compensators
7.3.1 Description
These pressure reducing compensators, which bolt-on to
the bottom of the directional valve, can be switched be
tween the individual compensator and 3-way pressure re
ducing functions. By energising solenoid Y, the valve is
switched into individual-compensator mode. In pressure-
reducing mode, preselection of the appropriate actuator line
allows a preset pressure to act at port A or B. The pressure
setting can be altered by hand or by electro-proportional so
lenoid (solenoid X).
The valves must be mounted on flange face U of the direc
tional valve.
7.3.2 Technical data
General characteristics Unit Description, value
Pressure range 1-4
electro-proportional
Pressure range 6-8
manual setting
Pressure range 1
2
3
4
6
7
8
bar 63
100
160
230
100
160
250
Operating pressure bar max. 250
Minimum pressure always bar 15 above tank pressure
Nominal flow rate l/min max. 25
Solenoid voltage V DC 12 or 24
Connector socket DT04-2P-EP04, AMP Junior Timer
Power consumption solenoid X
solenoid Y
Watt
max. 19
27
Duty cycle solenoid X
solenoid Y
% 100 at I
max
1,4 A (U
N
12 V) / 0,7 A (U
N
24 V)
100
Enclosure protection AMP: IP65 DT: IP67 (DIN EN 60529)
7.3.3 Performance graphs
7.3.3.1 Pressure control characteristic with propor
tional control of solenoid X
200
160
120
80
40
0,2 0,4 0,6 0,8 1 1,2 1,4
p [bar]
Pressure range [bar]
Solenoid current I
12V
0,1 0,2 0,3 0,4 0,5 0,6 0,7
24V
240
0
63
100
160
230
7.3.3.2 Typical pressure profile
3-way pressure control
Electroproportional
120
40
160
80
200
-30-40 -10 20-20
QA/B [l/min]
p A/B [bar]
0
-50
240
280
30 50
100
40
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L.8S directional valves
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7.3.4 Overview of sections
7.3.4.1 LU8SSDK.-… - Pressure reducing compensator switchable to 2-way compensator
Symbol Description Part number
X
Y
M
P
P`
LS
T
LU8SSDK2-1J12*00 100039398
switchable to 2-way compensator
pressure setting : electro-proportional p= 100 bar
connector socket: AMP Junior Timer
nominal voltage 12 V DC
X
Y
M
P
P`
LS
T
LU8SSDK3-1J24*00 defined by order
switchable to 2-way compensator
pressure setting : electro-proportional p= 160 bar
connector socket: AMP Junior Timer
nominal voltage 24 V DC
X
Y
M
P
P`
LS
T
LU8SSDK4-1T12*00 defined by order
switchable to 2-way compensator
pressure setting : electro-proportional p= 230 bar
connector socket: DT04-2P-EP04
nominal voltage 12 V DC
Y
M
P
P`
LS
T
LU8SSDK6-1T12*00/P= see order details chapter 1.1
switchable to 2-way compensator
pressure setting : manual p= 100 bar
connector socket: DT04-2P-EP04
nominal voltage 24 V DC
7.3.4.2 LU8SSDO.-… - Pressure reducing compensator not switchable
Symbol Description Part number
X
M
P
P`
LS
T
LU8SSDO1-1T24*00 100034455
not switchable to 2-way compensator
pressure setting : electro-proportional p= 63 bar
connector socket: DT04-2P-EP04
nominal voltage 24 V DC
X
M
P
P`
LS
T
LU8SSDO2-2T12*00 defined by order
not switchable to 2-way compensator
pressure setting : electro-proportional p= 100 bar
connector socket: DT04-2P-EP04
nominal voltage 12 V DC
X
M
P
P`
LS
T
LU8SSDO3-1T24*00 defined by order
not switchable to 2-way compensator
pressure setting : electro-proportional p= 160 bar
connector socket: DT04-2P-EP04
nominal voltage 24 V DC
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L.8S directional valves
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X
M
P
P`
LS
T
LU8SSDO4-1J12*00 100036098
switchable to 2-way compensator
pressure setting : electro-proportional p= 230 bar
connector socket: AMP Junior Timer
nominal voltage 12 V DC
X
M
P
P`
LS
T
LU8SSDO4-1T12*00 100035166
not switchable to 2-way compensator
pressure setting : electro-proportional p= 230 bar
connector socket: Deutsch plug DT04-2P-EP04
nominal voltage 12 V DC
Others on enquiry.
7.3.5 Connector socket
AMP Junior Timer
J
Deutsch plug DT04-2P-EP04
T
7.3.6 Dimensions
7.3.6.1 Pressure range 1 - 4
68
310
70,5 135
only with LU8SSDK
Test point
M10x1
7.3.6.2 Pressure range 6 - 8
135
68
70.5
265.5
Test point
M10x1
only with LU8SSDK
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L.8S directional valves
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8 End sections
8.1 End sections with no control function
8.1.1 Description
End sections with no control function are intended for the
end of a valve block when no other control functions are
needed. The LS signal is unloaded to tank.
The ports needed for the particular model are provided, as
are tapped holes for securing the valve block.
8.1.2 Overview of sections
Symbol Description Part number
LST
LU8SPUB-1*00 100040275
end section without port
LS to T
L
S
TP
TP
LU8SPUT-1M22*00 100038056
tank port T and pressure port P = M22 x 1,5
LS to T
LS
TP
TP
LU8SPUT-1M26*00 100039952
tank port T = M26 x 1,5
pressure port P = M22 x 1,5
LS to T
LSP
LSP
LU8SPWS-0M22*00 100041051
pressure port P = M22 x 1,5
LS port = M14 x 1,5
LS carry-over (if unloading, remember the LS signal)
8.1.3 Dimensions
8.1.3.1 LU8SPUB
28.5
8.5
14
33.560
121
13
M
8
13
87.5
18.5
Minimum length for calculating the total tie-rod length
8.1.3.2 LU8SPUT
20.5
33.5
30.5
35.5
M x1,522
M x1,522
102
2.5
M
8
16.5
53
9
46
15
124
13
88
14.5
T
P
Minimum length for calculating the total tie-rod length
8.1.3.3 LU8SPWS
121
77
14
87.5
13
38.5
20.5
37
48.5
M x1.522
M x1.514
2.5
102
53
44.5
9
15
M8
LS
P
Minimum length for calculating the total tie-rod length
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L.8S directional valves
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8.2 Priority section
8.2.1 Description
Intended for the end of a valve block, the LU8SPUO/PUP…
priority section includes a priority function for the external
control system supplied by the ports P
P
and LS, and the sur
plus flow side.
In the under-supply range (pump flow < total flow needed by
the valve block), the surplus flow side will receive only a por
tion of what it needs, or possibly (pump flow < priority flow
setting) no flow whatsoever.
The priority side can also be equipped with a pressure relief
valve that ensures a priority flow cut-off when the pressure
setting is reached. For oscillation-prone applications, a
damping element (e.g. An accumulator) can be connected
to a port specially provided for this purpose. Preferred appli
cations are in LS systems.
8.2.2 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Nominal flow rate l/min max. 120
Control Δp for the compensator bar 12
Pressure for flow cut-off om the priority side bar adjustable
8.2.3 Performance graphs
8.2.3.1 Pressure drop characteristic
25
20
15
10
5
0
20 40 60 80 100 120 140 160
Q [l/min]
A
B, C
0
Δp [bar]
A
P
Pump
port
to P
Surp
(Q
Priority
= zero)
at P
Surp
= P
LS
B P
Pump
port
to P
Surp
at Δp P
Surp
to LS > 20 bar
C
P
Pump
port
to P
priority
(control spool in neutral
position)
8.2.3.2 Flow cut-off on the priority side
160
120
80
40
0
50 100 150 200 250 300
Actuator flow Q [l/min]
Dp
P
!
T [bar]
0
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L.8S directional valves
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8.2.4 Overview of sections
Symbol Description Part number
P
M
LS
T
P
Surp
P
Priorität
LU8SPUP-0B10*01/P= see order details chapter 1.1
flow cut-up
port threads G1“ / BSP 1“
8.2.5 Dimensions
M22 x 1,5
160
236.5
202.5
51
87
44
30.5
32.5
62
92.5
13
14
44
49
M14x1.5
(30.5)
M14 x 1,5
15
14.5
M8
114
M14 x 1,5
18
51
41
46
86
G1“
58
14
Connection point for
damping element
Screw-in depths for
calculating the total
tie-rod length
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L.8S directional valves
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8.3 With direct-acting pressure relief
8.3.1 Description
For terminating the block with integral direct-acting pressure
relief (e.g. secondary pressure relief in LS systems).
The application limits must not be exceeded. A test point for
P, and tapped holes for securing the valve block are pro
vided.
8.3.2 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 300
Nominal flow rate l/min see characteristic curve
Pressure range bar
35 - 95
95 - 210
210 - 300
8.3.3 Characteristic curve
8.3.3.1 Pressure relief characteristic
250
200
150
100
02040
Q
T
[l/min]
300
60 80 100
350
Application
limit
Dp P ! T [bar]
8.3.4 Overview of sections
Symbol Description Part number
M
LS
LU8SPUD3-0M14*00/P= see order details chapter 1.1
end section
pressure range 210 … 300 bar (others on enquiry)
port thread to DIN 3852 - M14 x 1,5 (test point)
specify the pressure relief setting in bar
8.3.5 Dimensions
Minimum length for
calculating the total tie
bolt length
165
120
52
13
11,5
15
M8
2,5
102
68,5
13
84
46
26
56
M14x1,5
Test port
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L.8S directional valves
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8.4 With pressure reducing function e.g. for hydraulic joystick
8.4.1 Description
This end section includes a 3-way pressure reducing valve
and the ports PX and TX. The reduced pressure available
at port PX can be varied by the adjusting screw to any re
quired level from 10 to 100 bar. A typical application is pro
viding the supply for hydraulic joysticks. No tank unload fa
cility at the upper tie bolt gallery. The upper tank gallery is
not connected to the tank port.
8.4.2 Technical data
General characteristics Unit Description, value
Operating pressure bar max. 250
Flow rate at port PX l/min max. 15
Reduced pressure at PX preset bar 50
Reduced pressure at PX adjustable bar max. 100
8.4.3 Overview of sections
Symbol Description Part number
PX
TX
LU8SPUH-0B14*00/PX= see order details chapter 1.1
end section
port threads BSP¼“ / G¼“
8.4.4 Dimensions
G1/4”
BSP1/4”
27.5
10
2.5
13
29.5
117
19
38.5
83
20.5
13
M8
102
14
PX
PX
48,5
Minimum length for
calculating the
total tie-rod length
Adjusting
screw
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L.8S directional valves
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8.5 Load control valve with float position
8.5.1 Description
For terminating the block, this has an integral load-holding
valve with anti-shock function for port A. The two seat valves
in A and B to create the float position. When the directional
valve is in the neutral position, actuator line A is shut-off with
zero leakage and protected from unacceptably-high pres
sure peaks by an anti-shock function.
The mating directional valve is the last directional section in
the block and must be a special version e.g. /02 (LC8S) or
/24 (LP8S, LH8S) with spool type 4E. A typical application
is the arm function in wheel loaders and front loaders.
8.5.2 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 210
Actuator pressure bar max. 250
Port threads to DIN 3852 M18 x 1,5
Pilot ratio S15
S30
1,5 : 1
3 : 1
Anti-shock valve adjustable bar 100 … 250
Pressure drop across load-control function bar 30 at 63 l/min
Nominal voltage V DC 12 or 24
Power consumption Watt 50
Duty cycle % 100
Connector socket DIN 43650
Enclosure protection AMP Junior Timer: IP65
Deutsch plug DT04-2P-EP04: IP67 (DIN EN 60529)
8.5.3 Overview of sections
Symbol Description Part number
TAB
T
A
B
LU8SPUE-S15***-0M18J12*00/PA= see order details chapter 1.1
end section
actuator port A: load control function pilot ratio 1,5 : 1
nominal voltage 12 V DC
connector socket: AMP Junior Timer
specify the pressure relief setting in bar
T
A
B
T
AB
LU8SPUE-S30***-0M18T12*00/ PA= see order details chapter 1.1
end section
actuator port A: load control function pilot ratio 3 : 1
nominal voltage 12 V DC
connector socket: DIN 43650
specify the pressure relief setting in bar
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T
A
B
T
AB
LU8SPUE-S30***-0M18T24*00/P= see order details chapter 1.1
end section
actuator port A: load control function pilot ratio 3 : 1
nominal voltage 24 V DC
connector socket: DIN 43650
specify the pressure relief setting in bar
8.5.4 Connector socket
AMP Junior Timer
J
Deutsch plug DT04-2P-EP04
T
8.5.5 Dimension
123
2.5
102
49.5
5.5
87.5
15.5
13
53
6
67
257
90
M8
13
57
M18x1.5
M22x1.5
67
Minimum length for
calculating the
total tie-rod length
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8.6 Safety valve for electro-hydraulic
steering systems
8.6.1 Description
Block end section as safety valve for electro−hydraulic
steering systems. When the electro−hydraulic steering is
activated by energising the attached proportional valve
(e.g. LC8S), the two 3/2 directional valves are also ener
gised at the same time. As a result, the steering Orbitrol is
disconnected. In automatic mode, if manual (i.e. emer
gency) steering corrections have to be made without first
switching off automatic mode, a pressure develops in R or
L, depending on the direction the Orbitrol is turned.
This pressure passes through the shuttle valve to a pres
sure switch. The signal from the pressure switch cancels the
automatic function and all solenoids are de−energised.
Thus, the Orbitrol is directly connected to the steering cylin
der and the normal manual steering function is active.
8.6.2 Technical data
General characteristics Unit Description, value
Inlet pressure bar max. 210
Nominal flow rate l/min 25
Nominal voltage V DC 12
Power consumption Watt 27
Duty cycle % 100
Connector socket DIN 43650
Enclosure protection AMP: IP65 DT: IP67 (DIN EN 60529)
8.6.3 Overview of sections
Symbol Description Part number
RMLLS
A
B
0.5
LU8SPUL-0B14J24*00 100039804
end section
connector socket: AMP Junior Timer
nominal voltage 24 V DC
8.6.4 Connector socket
AMP Junior Timer
J
Deutsch plug DT04-2P-EP04
T
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8.6.5 Dimensions
G1/4"
59,5
30
50
59,5
90
102
13
2,5
135
22,5 19,5
69
273
2,5
22,5
62,5
84,5
20
44
64
M8
64
G1/4"
G1/4"
G1/4"
G1/4"
G1/4"
70
13
Minimum length for
calculating the
total tie bolt length
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9 Accessories
9.1 Seat valves series SVH04
9.1.1 Single and multi-monoblocks for attaching to L.8S valves
9.1.1.1 Symbols
SVH04M228S.-..
AB
A
B
1
2
SVH04M448S.-..
A
B
AB
A
B
1
3
2
4
SVH04M668S.-..
A
B
A
B
AB
A
B
1
3
5
2
4
6
SVH04M888S.-..
A
B
A
B
A
B
AB
A
B
1
3
5
2
4
6
7 8
SVH04M008S.-..
A
B
A
B
A
B
AB
A
B
1
3
5
2
4
6
7 8
A
B
9 0
Detailed information see data sheet 100-P-00043.
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9.2 Analogue systems
9.2.1 Overview of components
Description Ordering code Data sheet
Electrical joysticks (see data sheet) 100-P-700071
Plug Junior Timer 2-pole 100152575
Plug Junior Timer complete 100152579
Deutsch DT04-2P-EP04 100608468
Solenoid connection cable 100153209
9.3 Proportional amplifier
Description Ordering code Data sheet
Master Module Series EBM 100-P-700071
9.4 Assembly kit
9.4.1 Description
To assemble the individual control block with assured func
tional reliability, 3 tie-rods and 3 resp. 6 hex. nuts are always
necessary. Maximum tightening torque = 30 Nm. Tighten in
3 steps of 6, 16 and 30 Nm.
9.4.2 Ordering code
3 pcs. tie-rods M8 x ...... (required length in mm)
3 or 6 pcs. (depending on block configuration)
Seal-Lock sealing nut M8,
Part No: 100280470
Calculating the tie-rod length:
Inlet section + 48 mm (LP,LM,LH =37,5 mm) x no.
of directional valve sections + width of the end sec
tion
Example:
29+(48x2)+37,5+33,5 = 194 mm
For ordering purposes, always round up to the cal
culated tie-rod length to the next 10 mm.
In our example, we therefore need to order 3 pcs.
Tie-rods á M8 x 200 mm.
48 48 37.5 33,5
29
IMPORTANT: Maximum 10 directional sections in 1 valve block.
10 Liability
In the design and operation of hydraulic systems, all as
pects of the potential failure modes and all planned opera
tional conditions and uses of the equipment must be taken
into consideration.
Concerning risk assessment, please refer to the relevant
Standards. The use of components that are not Original
Bucher Replacement Parts and Accessories nullifies all
warranty.
11 Note
This catalogue is intended for users with specialist knowl
edge. To ensure that all of the conditions necessary for the
function and safety of the system are fulfilled, users must
satisfy themselves as to the suitability of the units described
here in. If there are any areas of doubt, please consult
Bucher Hydraulics.
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2024 by Bucher Hydraulics GmbH, D-79771 Klettgau
www.bucherhydraulics.cominfo.kl@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: 430.300.330.