Cat. G-Edit0E

G

LOGIC VALVES
Maximum
OperatingPressure 1MPa

GraphicSymbols

Valve Type

Rated Flow L/min
2 351020 30 50

100 200 300 500

10003000 6000

1650 63 80 100

Directional Control
Logic Valves
Directional and Flow
Control Logic Valves

Solenoid Operated
Directional Control
Logic Valves

XLDB

32 40

G-4

Ab

X

B

Y

A

Relief Logic Valves

25PageX

B

Y

31.5LDS25 32 40 50 63

LB

16253250

LBS

16253250

G-5

G-6Ab

Solenoid Controlled
Relief Logic Valves
XBYG-7A

Consult Yuken when detailed material such as dimensions figures is required.
G-1

Logic Valves
Yuken Logic Valves comprise cartridge typed elements and covers with pilot
passages. Various types may be combined for direction, flow rate and pressure
control. Yuken Logic Valves can be incorporated in manifold blocks to form
optimum integrated hydraulic circuits and compact hydraulic power units. Being
a poppet type, the elements permit high-pressure, high flow rates, high speed
and shockless shifting with low pressure drop. Typical applications include steel
mill equipment, injection moulding machines, machine tools and so on. Inaddition, YUKEN's logic valves meet the cavity specifications (elementinsertion holes and cover mounting dimensions) of the ISO standard (ISO7368
TWO-PORT SLIP-IN CARTRIDGE VALVES CAVITIES).

■ Features●Multifunction performance in terms of direction, flow and pressure can be obtainedby combining elements and covers.
●Poppet-type elements virtually eliminate internal leakage and hydraulic locking.
Because there are no overlaps, response times are very high, permitting high-speed
shifting.
●For high pressure, large capacity systems, optimum performance is achieved withlow pressure losses.
●Since the logic valves are directly incorporated in cavities provided in blocks, thesystem is free from problems related to piping such as oil leakage, vibration andnoise, and higher reliability is achieved.
●Multifunction logic valves permit compact integrated hydraulic systems which
reduce manifold dimensions and mass and achieve lower cost conventional types.

G-2

Logic ValvesLogic Valves■ Structure and Functions
As shown below, a logic valve consists of a cover, a sleeve, a poppet and a spring incorporated in ablock. Although it is a simple two-port valve designed to open and close the poppet in accordance withthe pressure signals from the pilot line, it serves as a multifunctional valve for controlling the direction,
flow and pressure by controlling the pressure signals. Standard covers have several pressure signal ports(pilot ports) and control valves for control purposes are available. The covers are spigot mounted. Thereis no risk of oil leakage.

Basic Structure

Directional Control
Logic Valve

Relief Logic Valve
（LB）

（LD）
X

CoverSpringSleeve

X

B

PoppetBBAA (100％)

Ratio of poppet
areaAYPoppet WithoutCushion

A

Poppet WithCushion

X

A（ 50%…………LD･LDS
4.2%…………LB･LBS ）A 150%…………LD･LDS（ 104.2%…………LB･LBS ）ABXSolenoid Operated Directional
Logic Valve (LDS)

Directional & Flow Control
Logic Valve

Solenoid Controlled Relief
Logic Valve (LBS)G
Logic Valves（LD−＊−＊−S−1 – 3）

X
B
X

X

Y

Y

B

B

A
A

A

● Functions, working area ratios and features
Functions

Graphic Symbols

Working area ratios (AA：AB)

Features●Poppet Shape
Without cushion ( LD
LDS −＊−＊) : High-speed shiftDirection

X

With cushion ( LD
LDS −＊−＊−S) : Shockless shift

BA

2：1

Direction and Flow

●Poppet Shape

1With cushion (LD−＊−＊−S− 2 ) : Flow control
3X●No leakage between port A to B.
●Flow A to B only is possible.
●Response time and shock can be adjusted by orifice selection.

BARelief●No leakage between port A and B.
●Flow A to B and B to A are possible.
●Response time and shock can be adjusted by orifice selection.

XBAY

24：1

●Remote and unloading control is possible with vent circuit.
(LB−＊−＊)●Two or three pressure controls are possible in combination of solenoid
operated directional valve and pilot relief valve. (LBS−＊−＊)

Logic Valves

G-3

Directional Control/Directional & Flow Control Logic Valves
These valves are 2-way directional valves designed to open and close thecircuits in accordance with pressure signals from the pilot lines. They are usedas multifunctional valves for controlling flow directions or flow directions andrates. Standard covers are available so that optimum valves can be selected forcontrol purposes.

LD-32■ Speciﬁcations■ List of Cover TypesMax.

Model Rated Flow OperatingPressureNo.
L/min
MPa

Cracking
Pressure
MPa

Ratio ofPoppet
Area

130

1.6

LD−25350

3.0

LD−32500

2：1

LD−40

850
1400

LD−632100

LD−80

3400

48

LD−1005500

86Annulararea
50％Standard(None)

5.3

LD−50

Refer toModel No.
Designation

16 25 32 40 50 63 80 100○ ○ ○ ○ ○ ○ ○ ○

X
B

9.1
14.8
29.8

Note: The rated flow is values with a pressure drop of 0.3 MPa,
fluid viscosity 35 mm²/s.

AWith
CheckValve(4)LD－32 －05 － S －1 － X 05 －12
Design number (LD-80,100.......11)
Designation of orifice
Location of orifice (see the table right)
None : no orifice
X : Pilot port X
Z1 : Pilot port Z1
S : Port leading to spring

Cover type (See the table right)
None, 1, 2, 3, 4, 5

Directional & Flow Control

Poppet shape★
None : Without cushion
S : With cushion

Cracking pressure (A→B)
None : No Spring
05 : 0.05 MPa
20 : 0.2 MPa

Valve Size : 16, 25, 32, 40, 50, 63, 80, 100

Directional control logic valves/Directional & flow control
logic valves★Poppet shapes
The type without a cushion and the type with a cushion are bothsuitable for high-speed shifting and shockless shifting respectively.
For directional and flow control logic valves, be sure to specify"poppet with cushions".

XS○ ○ ○ ○ ○ ○ － －Z1
BA■ Model Number Designation

G-4

Valve Size

GraphicSymbols

kg

LD−16

31.5

Cover Type
Designation

Mass

Directional Control(NOTE)

LD-80

WithShuttle
Valve
(5)

X

WithStroke
Adjuster
(1)

X

Z1 Z2

○ ○ ○ ○ ○ ○ － －B
A

With Check
Valve & Stroke
X
Adjuster(2)○ ○ ○ ○ ○ ○ ○ ○B
AS○ ○ ○ ○ ○ ○ － －Z1
BA

With Shuttle
Valve & Stroke
X
Adjuster(3)

Logic Valves

Z1
BA

Z2

○ ○ ○ ○ ○ ○ － －Logic Valves

Solenoid Operated Directional Control Logic Valves
These solenoid operated directional control logic valves are composed of
directional control valves and solenoid operated directional valves combined
together. The solenoid operated directional valves serve to switch pilot lines andthe directional control valves are used to control the direction of the main circuits.
Standard covers provided with various control valves are available to provide
optimum control.

■ Speciﬁcations
ModelNo.

Max.
(NOTE)
Rated Flow Operating
Pressure
L/min

LDS−25350

LDS−32500

LDS−40850

LDS−501400

LDS−63

2100

CrackingPressure

MPa

Ratio ofPoppet
Area

MPa

Masskg
4.2

Refer toModel No.
Designation

31.5

2：1

Annular
area
50％

6.5
10.3
18.6
33.6

Note: The rated flow is values with a pressure drop of 0.3 MPa, fluid viscosity 35 mm2/s.

■ List of Cover Types

Design No.
LDS-50, 63.........13

Cover Type
Designation

Type of electrical conduit connection
None：Terminal box (standard)
N：Plug-in connector (option)
Type of manual override
None：Manual override pin (standard)
C：Push button and lock nut (option)
Coil type
A＊：AC, R＊：AC→DC rectified
D＊：DC, RQ＊：AC→DC rectified(quick return)(LDS−50, 63)
Designation of orifice

Location of orifice
None：No orifice
P：Pilot port P, B：Pilot port B
A：Pilot port A, X：Pilot port X
Solenoid operated valve
None：With solenoid operated valve
O：Without solenoid operated valve
Cover type (See the table right) 1, 2, 3, 4, 5, 6
Poppet shape None：Without cushion
S：With cushion

Cracking pressure None：No spring（A→B）
05：0.05 MPa
20：0.2 MPa

Solenoid operated directional control logic valve

Normally
Open withShuttle Valve(6)Normally Closed(1)

SX

32405063○○○○○○○○○○○○○○○○○○○○○○○○○YBAb

Normally Open(2)XYGBA

NormallyClosed withShuttle Valve
(3)

b

X

Z1

YB
AbX

Z1

YB

b

X

25b

Normally Openwith Shuttle
Valve
(4)

Valve Size：25, 32, 40, 50, 63

Valve Size

Graphic Symbols

Logic Valves■ Model Number Designation
LDS-32-05-S-1-O-X 05-A100-C-N-14

A

Y

Z1

○○○○○B
A

Note: In case of LDS- ＊-＊-＊-＊-O (without solenoid operated valve),
the graphic symbol for the solenoid operated valve is excluded.

Normally
Closed withShuttle Valve(5)

Logic ValvesbX

YZ1BAG-5

Relief Logic Valves
These relief logic valves are used to protect pumps and control valves fromexcessive pressure and control the pressures of their hydraulic lines at constantlevels. With the help of vent lines (Z1 or Z2 port), they are also capable ofremote and unload control.

■ Speciﬁcations
Max.
OperatingPressureMPa

Pres. Adj.
Range
MPa

Max. FlowL/minMasskg

LB−16−＊−＊−10125

3.6

LB−25−＊−＊−10250

4.5

Model No.

31.5

LB−32−＊−＊−110.5 - 31.5

LB−50−＊−＊−11■ Model Number Designation
LB － 32 － V － Z1 － 11
Design number
LB16, 25…………10
LB32, 50…………11500

6.7

1200

16.1

■ List of Cover Types
Cover Type
Designation

Cover type (See the table right)
None, Z1, Z2

Standard(None)

Specify only for high-vent types★
Valve size：
16, 25, 32, 50

Graphic Symbols

YX

1625

3250

○○

○

○

○

○

○

○

○

○

○

○

BA

Relief logic valve★Use high-vent pressure types if the shifting time fromunloading to on-loading is reduced.

Valve Size

VentControlled
(Z1)

XY

Z1
BAVentControlled
(Z2)

BA

G-6

Logic Valves

YZ2X

Logic Valves

Solenoid Controlled Relief Logic Valves
These solenoid controlled relief logic valves are composite control valveshaving solenoid controlled directional and pilot relief valves andvent restrictors combined together. They are used to put pumps into unloading
operation, with the solenoid controlled directional valves serving to select pilotlines, or to place hydraulic system two or three pressure controls, with the pilot
relief valves in action.

■ Speciﬁcations
Model Numbers
LBS−16−＊−＊−＊−14
LBS−25−＊−＊−＊−14
LBS−32−＊−＊−＊−14Max.
OperatingPressure
MPa

Pres. Adj.
Range
MPa

31.5

0.5 - 31.5

LBS−50−＊−＊−＊−14Max. Flow
L/min

Masskg125

3.6 - 8.5250

4.5 - 9.4500

6.7 - 11.6

1200

16.1 - 21.0

■ Model Number Designation
Design number
Type of electrical conduit connection
None：Terminal box (standard)
Ｎ：Plug-in connector (option)
Type of manual override
None：Manual override pin (standard)
Ｃ：Push button and lock nut (option)
Coil type
Ａ＊：AC
Ｄ＊：DC
Ｒ＊：AC→DC rectified

GLogic Valves

LBS － 32 － V － 1 － A100 －C － N － 14

Cover type (See the following page)
0：No solenoid operated valve
1：Normally closed, for unloading(Solenoid operated valve spool type: 2B3A)
2：Normally open, for unloading(Solenoid operated valve spool type: 2B3B)
3：Normally closed, with vent restrictor (Solenoid operated valve spool type: 2B3A)
4：Normally open, with vent restrictor (Solenoid operated valve spool type: 2B3B)
5：Two-pressure control (Solenoid operated valve spool type: 2B2)
6：Three-pressure control (Solenoid operated valve spool type: 3C9)
7：Two-pressure control and unloading(Solenoid operated valve spool type: 3C3)
Specify only for high-vent types★
Valve size：16, 25, 32, 50
Solenoid controlled relief logic valve★Use high-vent pressure types if the shifting time from unloading to on-loading is reduced.

Logic Valves

G-7

■ List of Cover Type (LBS)
Cover Type
Designation

Valve Size

Graphic Symbols
16253250

Cover Type
DesignationaWithout
Solenoid Valve(0)XY○○○○BAThree Pressure
Control
(6)
X

○X

○○

○○○○

○

○

○

○

Y

○aB

Two Pressure
Control andUnloading(7)○X○○○○○○○○○○○○○○YB
Ab

X

YBAb

Two Pressure
Control
(5)
XX

YB
A

BX

b○Yb

Y
B
A

G-850YA

Normally Openwith Vent
Restrictor
(4)

32Ab

Normally
Closed withVent Restrictor
(3)

25

B

A

NormallyOpen for
Unloading
(2)

16bb

Normally
Closed for
Unloading(1)

Valve Size

Graphic Symbols

Logic Valves