Eaton VICKERS DG3V-10 Series User manual

5007.01/EN/1099/M
DG3V-10/DG5V-10 Solenoid Pilot Operated
Overhaul Manual VICKERS®
Directional Control Valves

2
Contents
Section I. Introduction 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Model Code Breakdown 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section II. Description 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section III. Valve Operation 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section IV. Pilot Valve Section 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section V. Internal Valve Functions 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section VI. Installation 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section VII. Service, Inspection & Maintenance 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section VIII. Overhaul 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DG5V-8-S/H-*(C)-10 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DG3V-8-*(D) (2/8 / 28)-10 26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DG4V-3(S)-*A(L)/B(L)-FJ/FW-60 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DG4S4-01*B/C-(U)-*-60 28
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Section IX. Start-Up and Test 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3
Section I. - Introduction
A. Purpose of Manual
This manual describes operational characteristics,
maintenance requirements, and overhaul information for
Vickers DG3V-10 and DG5V-10 series single stage and two
stage pilot operated and hydraulic operated directional
valves. The information contained herein pertains to the
latest design series as listed in Table 1.
B. Related Publications
Service parts and installation dimensions are not contained
in this manual. The parts and installation drawings listed in
Table 1 are available from any Vickers Distributor
C. Model Codes
Variations within each basic model series are covered in the
model code. See Table 2. Each unit has a model code
stamped into the main stage nameplate. Service inquiries
should always include the complete model number as noted
on the nameplate.
Model
Description Application Drawing Parts Drawing
DG3V-10*A
DG3V-10*C 5007.05/EN/0496/S
DG3V-10*D
DG5V-10*A
DG5V-10*B
5007 01/EN/0196/
A
DG5V-10*C
5007
.
01/EN/0196/
A
DG5V-10*D 5007.06/RN/0496/S
DG5V-10*DA
DG5V-10*DB
DG5V-10*N
Table 1. Related Publications

4
Model Code Breakdown
Model Code
23 76 81 9
Special Seals
(Omit if not required)
F3 - Seals for fire resistant fluids.
F6 - Seals for water glycol.
Directional Control Valve
DG3V - Subplate mounting; pilot
operated, remote operator. Pressure
rating 350 bar (5000 psi) for P, A & B
ports. (See pressure tabulation below.)
Valve Size
10 - Valve size CETOP 10, ISO 4401-10,
NFPA D10
Gauge Ports
Blank - .4375-20 UNF-2B Thread
B-1/4BSP Thread
Spool Types
0- Open to T all ports
1- Open P&A to T, closed B
2- Closed to T all ports
3- Closed P&B, open A to T
4 - Tandem P to T, closed crossover
6- Closed P only, open A&B to T
7- Open P to A&B, closed T
8- Tandem P to T, open crossover
9- Open to T all ports over tapers
11 - Open P&B to T, closed A
31 - Closed P&A, open B to T
133 - Closed P, open A&B to T over tapers
52 - Closed center, regen. by sol. ‘A’
521 -Closed center, regen. by sol. ‘B’
Spool/Spring Arrangement
Blank - No spring
A- Spring offset to cylinder ‘A’
C- Spring centered
D- Pressure centered 140-210 bar
(2000 - 3000 psi)
(See spool/spring combinations below)
Left Hand Build
L- ‘A’ Models only, omit if not
required.
Fast Response
X- Not available with CETOP 3 pilots or
pressure centered ‘D’ and ‘DB’ models.
Spool Control Modifications
(Omit if not required)
1- Stroke adjustment (both ends)
available on C & Blank
(no spring) models)
2- Pilot choke adjustment
(available on all models)
3- Pilot choke and stroke adjusters
(both ends) (available on C & Blank
(no spring) models)
2
3
4
6
7
9
7- Stroke adjusters on cylinder ‘A’ end
only (available on AL, C & Blank
(no spring) models)
8- Stroke adjusters on cylinder ‘B’ end
only (available on AL, C, & Blank
(no spring) models)
2-7 - If both are required (available on A,
C, & Blank (no spring) models)
2-8 If both are required (available on
AL left hand build, C & Blank (no
spring) models)
Check Valve in Pressure Port
Not available for ‘D’ models
Omit if not required.
K- 0,3 bar (5 psi) check
Q- 2,4 bar (35 psi) check
R- 3,4 bar (50 psi) check
S- 5,2 bar (75 psi) check
Design Number
Subject to change. Installation
dimensions remain as shown for design
numbers 10 through 19.
Special Modifications
(Omit if not required)
EN503- Reduced overall axial length for
close quarter applications.
8
10
5
410
11
11
5
12
12

5
Special Seals
(Omit if not required)
F3 - Seals for fire resistant fluids.
F6 - Seals for water glycol.
Directional Control Valve
DG5V - Subplate mounting; solenoid
controlled; pilot operated. Pressure
rating 350 bar (5000 psi) for P, A, & B
ports. Note
Note: 210 bar (3000 psi) for pressure
centered D models.
Valve Size
10 - Valve size CETOP 10, ISO 4401-10,
NFPA D10
Pilot Valve Type
H- CETOP 3 mounting pattern, High
performance
S- CETOP 3 mounting pattern, Std.
performance
A- CETOP 5 mounting pattern, Air gap
F- CETOP 5 mounting pattern, Wet
armature
V - CETOP 5 mounting pattern, Wet
armature
W-CETOP 5 mounting pattern, Wet
armature
(See page NO TAG for descriptions)
Reducer Module
(Omit if not required)
R- A (air gap) and W (wet armature)
piloted models when pilot pressure
exceeds 210 bar (3000 psi); F and V
(wet armature) when pilot pressure
exceeds 310 bar (4500 psi).
Gauge Ports
Blank - .4375-20 UNF-2B Thread
B-1/4BSP Thread
M-ISO 6149 port
Spool Types
0- Open to T all ports
1- Open P&A to T, closed B
2- Closed to T all ports
Fast Response
X- (Omit for standard internal pilot
pressure models)
Note
Not available for pilot pressures above
210 bar (3000 psi), pressure centered
models must have ‘DA’20-70 bar
(300-1000 psi) in model code. Not
available for H or S piloted models.
Spool Control Modifications
(Omit if not required)
1- Stroke adjustment (both ends)
(available on B, C, & N models)
2- Pilot choke adjustment (available
on all models)
3- Pilot choke and stroke adjustments
(both ends) (available on B, C, & N
models)
7- Stroke adjustment on cylinder ‘A’
end only (available on A, B, C, & N
models)
8- Stroke adjustment on cylinder ‘B’
end only (available on AL, B, C, N,
& D(*) models)
2-7 - If both are required (available on A,
B, C, & N models)
2-8 - If both are required (available on
AL, B, C, N, & D(*) models)
CAUTION
Stroke adjust pilot pressure
models are rated to a
maximum of 210 bar (3000
psi). Use reducer module if pilot
pressure exceeds 210 bar (3000 psi).
External Pilot Pressure
E-External pilot pressure. Omit for
internal pilot pressure models.
Internal Pilot Drain
T-Internal pilot drain to ‘T’port. Omit for
external pilot drain models.
Check Valve in Pressure Port
Not available for D(*) models.
Omit if not required.
K- 0,3 bar (5 psi) check
Q- 2,5 bar (35 psi) check
R- 3,5 bar (50 psi) check
S- 5, bar (75 psi) check
1
2
3
4
5
8
7
6
3- Closed P&B, open A to T
4 - Tandem P to T, closed crossover
6- Closed P only, open A&B to T
7- Open P to A&B, closed T
8- Tandem P to T, open crossover
9- Open to T all ports over tapers
11 - Open P&B to T, closed A
31 - Closed P&A, open B to T
33 - Closed P, open A&B to T over tapers
52 - Closed center, regen. by sol. ‘A’
56 - A&B to T, P blocked, regen.
by sol. ‘A’
521 -Closed center, regen. by sol. ‘B’
561 -A&B to T, P blocked, regen.
by sol. ‘B’
Spool/Spring Arrangement
A- Spring offset
B- Spring centered with solenoid ‘A’
removed
C- Spring centered
D- Pressure centered 210-350 bar
(2000-3000 psi)
DA - Pressure centered 20-70 bar
(300-1000 psi)
DB - Pressure centered 70-210 bar
(1000-2000 psi)
N- Detented
Left Hand Build
L- Single solenoid models only, omit
if not required.
Manual Override Options
CETOP 3 piloted models only, omit if not
required.
Blank - Plain override in solenoid ends
only.
H- Waterproof override in solenoid
ends only.
H2- Waterproof override in both ends of
single solenoid.
P2- Plain override in both ends of single
solenoid.
Y- Lockable manual override in
solenoid ends only.
Z- No override in either end.
9
10
11
12
13
14
2 3 4 75 81 10 11 12 13 14 15 16 17 18 199262021 22 23 24 25 27
628
15
Model
C
ode

6
Section II. - Description
A. General
Directional valves are devices used to change the flow
direction of fluid within a hydraulic circuit. A valve is
designed to control the direction of movement of a work
cylinder or the direction of rotation of a fluid motor.
B. Basic Four-Way Sliding Spool Directional Valve
Construction
Vickers valve bodies have a precision machined bore in
which a very close tolerance spool is suspended on a film of
hydraulic fluid. Spool lands and body cavities are designed
to divide the bore openings into separate chambers. Ports in
the body lead into these chambers so that spool position
determines which ports are open or closed. See Figure 1. Oil
flow is directed from one port to another within the body and
out of a port to the work
C. Two Stage Directional Valve Construction
Two stage directional valves are pilot pressure operated. A
two stage valve is constructed by combining a pilot valve
and a larger main stage valve into one assembly. The pilot
valve, usually a DG4S4 or DG4V-3 is mounted on top of the
main stage valve. The pilot valve controls spool movement
with the elecrical solenoids. When a solenoid is energized
(activated), the pilot spool moves and fluid is diverted to the
mainstage; thus controlling main stage spool movement.
Figure 2 illustrates the basic construction of a two stage,
pilot operated directional valve.
Figure 1. Spool Type Four-Way Valve
Figure 2. Typical ‘DG5’Type Solenoid Controlled, Pilot Operated Valve

7
Section III. - Valve Operation
A. General
Directional valve operation is determined by four factors:
spool type, spool positioning, method of control, and special
features. Proper selection of the above factors establish and
regulate desired flow paths through the internal ports of the
valve. The following information discusses those factors with
respect to valve operation.
B. Spool Types - Main Stage Section
Operation of spools are governed by their design as well as
the means of control. The most common designs are open
center, closed center and tandem. During the following
discussion, basic spool design is related to valve port
openings, with the spool in center position. Port openings
are stated as: P-Pressure Port, A&B-Actuator Ports, and
T-Tank or Reservoir Port.
1. Open Center Spools (0, 1, 9 and 11 types): Open center
valves are used in single operations where no other
operation is performed by the same source of power and
where cylinders do not have to be held by pressure. Open
center spools are also used to minimize shock in a system.
Shock develops when a valve spool is shifted from one
position to another across center position. The smoothest
possible minimum shock condition is obtained when fluid
under pressure is allowed to discharge to tank as the spool
passes center condition.
Open center with (A) or (B) ports blocked. A spool of this
type is generally used to operate a cylinder. When the spool
is centered, a cylinder port is blocked and the cylinder is held
in a definite position. In some circuits, flow from the tank port
is piped into the pressure port of another valve. This allows
the same source of power to operate two different cylinders.
This type of arrangement may be used in a system
containing a number of operations. However, each operation
must be performed in a certain sequence, with only one
operation taking place at any one time.
A. Type ‘0’spool is designed with ports (P), (B), (A) and
(T) interconnected when the spool is in center
position.These ports are momentarily interconnected
during spool crossover when the pilot valve solenoid is
activated. This permits smooth rapid cycle operation.
AB
PT
TAPB
Open Center
B. Type ‘1’spool is designed with ports (P), (A) and (T)
interconnected. Port (B) is blocked in center position.
AB
PT
‘‘B’’ Closed - Pressure Open
to Tank through ‘‘A’’
TAPB
C. Type ‘9’spool is similar to type ‘0’spool except all
ports are partially open in center position.
Open Center, Partial, All Ports
AB
PT
TAPB
D. Type ‘11’spool is a type ‘1’spool reversed in the
bore. The type ‘11’spool interconnects (P), (B) and (T) in
center position with (A) blocked.
AB
PT
‘‘A’’ Closed, Pressure Open to
Tank through ‘‘B’’
TAPB
2. Closed Center Spools (2, 3, 6, 31, 33, 52 and 521 types):
Closed center spools are used where two or more operations
are performed by a single pump or an accumulator. Closed
center valves prevent the loss of fluid from the pump or
accumulator when the spool crosses center.
A. Type ‘2’spool blocks ports (P), (A), (B) and (T) from
one another in the center position. The ports are
momentarily blocked during spool crossover.
AB
PT Closed Center - All Ports Closed
TAPB

8
B. Type ‘3’spool is designed with ports (A) and (T)
interconnected and ports (P) and (B) blocked in the
center position.
AB
PT Pressure and ‘‘B’’ Closed - ‘‘A’’ Open to Tank
TAPB
C. Type ‘6’spool is interconnected at ports (A), (B) and
(T). Port (P) is blocked in the center position.
Pressure Closed - ‘‘A’’ & ‘‘B’’ Open to Tank
AB
PT
TAPB
D. Type ‘31’spool is a type ‘3’spool reversed in the
bore. A type ‘31’spool is interconnected at ports (B) and
(T), but blocked at ports (P) and (A) in the center position.
AB
PT Pressure and ‘‘A’’ Closed - ‘‘B’’ Open to Tank
TAPB
E. Type ‘33’spool provides controlled leakage from port
(A) and (B) to port (T). Port (P) is blocked in the center
position.
AB
PT Closed Center - Bleed ‘‘A’’ & ‘‘B’’
TAPB
F. Type ‘52’spool
AB
PT
Closed Center, Regen. by Solenoid ‘A’
TAPB
G. Type ‘521’spool
AB
PT
Closed Center, Regen. by Solenoid ‘B’
TAPB
H. Type ‘56’spool
TAPB
AB
PT
I. Type ‘561’spool
TAPB
AB
PT
3. Tandem spools (4 and 8 types): Tandem spool valves are
used in hydraulic circuits where two or more hydraulic
cylinders or motors are controlled from a single source of
power. The valve’s spool is designed so that in center
position, all cylinder connections are blocked and full pump
delivery is connected to tank. The tank connection of one
valve may be connected to the pressure connection of
another valve and both valves operated simultaneously as
long a the combined pressures developed by the two loads
are within the capabilities of the power source.

9
A. Type ‘4’spool allows oil to circulate freely from port
(P) to port (T) in the center position. Ports (A) and (B) are
blocked to the workload.
TAPB
AB
PT Closed Crossover, Pressure to ‘‘T’’
with ‘‘A’’ & ‘‘B’’ Blocked
B. Type ‘8’spool is designed similar to type ‘4’spool.
Ports (P) and (T) are connected in the center position.
However, ports (A) and (B) are momentarily open during
spool crossover.
TAPB
AB
PT Tandem, Open Crossover, Pressure to ‘‘T’’
with ‘‘A’’ & ‘‘B’’ Blocked
C. Methods of Spool Control, Main Stage
1. Remote Pilot Source: Main stage valves are available
for use with a remote source. This means that the valve is
shifted from a remote pressure source by other valves in
the logic circuit.
2. Integral Pilot Valve: The integral pilot type two stage valve
is a very common valve used in the field today. Two stage
valves allow large volumes of fluid to be switched to and from
an actuator with minimum power required for control.
Reference figures 3 through 7 shown in the following section.
D. Main Stage Spool Position
Main stage spools are positioned within the valve by special
arrangements. The four basic main stage positioning
arrangements are: no spring-floating, spring centered, spring
offset and pressure centered.
The following paragraphs (1 through 4) describe these
arrangements. A fifth function can be obtained by the use of a
detent pilot valve. This function is described in paragraph five.
1. No Spring-Floating: When centering springs are omitted
from the main stage spool, the spool is said to be floating. If
control pressure is removed, a floating spool can move from
its last position under the influence of gravity or tank line
pressure. This must be considered during the design of the
system. Units with floating type spools have the model code
letter omitted. Figure 3 illustrates floating spool positioning in
a two-stage valve.
Fi
g
ure 3. No Sprin
g
s, Floatin
g
Model
Solenoid ‘‘A’’ is energized and shifts pilot spool to the
right. This opens pressure to pilot port ‘‘A’’ and the main
stage spool.
When solenoid ‘‘A’’ is energized, the main stage spool
will shift left. Flow from P³A and B³T is obtained.
Main stage spool will stay in this position until solenoid
‘‘B’’ is energized, but may float to other positions with
both solenoids de-energized.
1.
2.
3.
AB
TAPBT
P
BA
2. Spring Centered: A spring and washer arrangement is
used on both ends of the main stage spool in the spring
centered configuration. If control pressure is removed from a
spring centered spool, the valve will go to the center position
due to spring force. Two configurations of a two-stage spring
centered valve can be obtained, a type ‘B’and a type ‘C’. If
one solenoid is used on a spring centered pilot valve, the
model code is identified with the letter ‘B’. When two
solenoids are used, the model code is identified with the
letter ‘C’. Figure 4 illustrates spool positioning of a two-stage
spring centered ‘C’model.
Figure 4. Spring Centered ‘‘C’’ Model
Solenoids are de-energized. Pilot spool is in center
position due to spring force.
Main stage springs and washers keep main stage
spool at center position. Flow is A & B³T with ³P
blocked.
When solenoid ‘‘A’’ is energized, the pilot spool will
shift to the right, causing the main stage spool to
shift left. Flow would then be P³A and B³T.
1.
2.
Main
Stage
Spring
Main
Stage
Washer
TAPBT
AB
P
BA

10
3. Spring Offset: Single stage spring offset models use one
spring to return the spool to an offset position. In two-stage
models, the spring and washer is removed from the main
stage and offset action is obtained from the pilot valve.
Offset pilots have a solenoid removed from the spring end of
the valve. Spring offset pilots have a solenoid removed from
the spring end of the valve. Spring offset pilots control the
main stage when the solenoid is de-energized, through
spring action, so long as pilot pressure is available. Spring
offset valves have the letter ‘A’stamped into the nameplate.
Figure 5 illustrates an offset two-stage valve.
Figure 5. Spring Offset ‘‘A’’ Model
The spring returns pilot spool to ‘‘A’’ offset position
and shifts main stage spool. Main stage oil flow is
P³A and B³T.
Solenoid is
de-energized
Main
Stage
TAPBT
B
P
BA
WARNING
If pilot pressure is lost, mainstage spool is free to float.
4. Pressure Centered: Pressure centered valves provide more
positive centering arrangement than normal spring centered
valves. This is accomplished in the following manner:
Assume both pilot valve solenoids are de-energized and the
main stage spool is positioned to the left (see Figure 6). Pilot
pressure is applied to both ends of the main stage from the
number seven (7) pilot spool. The sleeve moves to the right
under the influence of the spring and pilot pressure until the
position shoulder is contacted. Since the sleeve and piston
areas are greater than the total spool area at the right hand
end of the valve, the sleeve continues to move to the right
carrying the piston with it until it contacts the valve body
(center position).
Assume the main stage spool was positioned to the right
with both pilot valve solenoids de-energized, pilot pressure is
applied to the sleeve and piston areas on the left side but the
sleeve is bottomed against the valve body at this time. Only
the piston area applies force to the left end of the spool.
Since the spool land area at the right side is greater than the
piston area, the spool will be forced to the left until the piston
shoulder butts against the sleeve (center position).
If pilot pressure falls below 20 bar (300 psi), the centering
springs will cause the spool to center within the valve body.
Figure 6. Pressure Centered ‘‘D’’ Model
1.
2.
3.
Shoulder
of piston
Piston
Sleeve ABPTT
AB
P
BA
Solenoids are de-energized. Pilot spool is in center
position. (P³A & B, T blocked) (shown).
Pilot pressure keeps main stage spool in center
position. Flow is blocked to all ports.
When solenoid ‘‘B’’ is energized, the pilot spool shifts
to the left. Oil under pressure enters piston area
causing the main stage spool to shift to the right. Main
stage flow from P³B and A³T is obtained.
Pressure centered valves are not available with integral
check valves. Pressure centered models have the letter ‘D’
stamped into the unit nameplate. Figure 6 illustrates
spool/spring arrangements on pressure centered models.
Note
A fifth condition of the main stage spool can be
obtained through the use of a detent pilot stage.
Refer to the following paragraph.
5. Detent Valve Operation: Detent valve operation can be
achieved by installing a detent into the pilot valve. A detent is
assembled on one or both ends of the pilot spool depending on
the type of pilot valve used. When a pilot valve solenoid is
de-energized, the detent holds the pilot spool in the last position
attained and the main stage spool remains in its last position.
WARNING
If pilot pressure fails or falls below the minimum
requirement of 5 bar (75 psi), the main stage spool
will shift to center position even though the pilot
valve remains in the last detent position. For this
reason, flow conditions in center or neutral position
must be selected with care.

11
Detent models are indicated by the letter ‘N’stamped into
the unit nameplate. Figure 7 illustrates the spool/spring
arrangement on detent models.
Fi
g
ure 7. Detented ‘‘N’’ Model
Solenoid ‘‘A’’ is energized and shifts pilot spool to the right.
Which causes main stage spool to shift left. Oil flow from
P³A and B³T is obtained.
Main stage spool remains in position attained due to pilot
valve detent until solenoid ‘‘B’’ is energized. (Note: If pilot
pressure fails, the main stage will shift to center position.
1.
2.
3.
Detent
Main
Stage
ABPTT
Pilot
Solenoid AB
P
BA
E. Optional Features (Main Stage)
Control of the mainstage spool travel can be modified with
certain optional features. The most common features are
discussed in the following paragraphs.
1. Stroke Limiter Adjustment (Fig. 8): Main stage spool
travel can be limited by using stroke adjust covers. Stroke
adjust covers may be used on one or both ends of the main
stage section. When the stroke is limited, maximum flow
through the valve is reduced (assuming same inlet pressure).
This slows the actuator movement.To limit the spool travel,
loosen the jam nut and turn adjusting screw clockwise.
Figure 8. Stroke Adjuster Feature
2
7
5
1
3
4
6
Main
Stage
Spool
Part No. Part Name
1
2
3
4
Cover
Spring
O-Ring
Back-up Ring
Part No. Part Name
5
6
7
Piston
Jamnut
Adjuster Screw
2. Pilot Choke Option (Fig. 9): A pilot choke increases the
amount of time it takes to shift the main stage spool from
one position to another. Increasing shift time lowers the
possibility of developing large flow transients in the circuit. A
pilot choke is designed to allow free flow to one end of the
main stage spool but restricts flow out of the opposite end.
The rate of spool travel, in either direction, can be slowed by
loosening a locknut and turning an adjusting screw
clockwise. To increase the rate of spool travel, turn the
adjusting screws counterclockwise. When a pilot choke is
used, pilot pressure should be taken from a constant
pressure source. The pilot choke is mounted between the
pilot valve and the main stage sections.
Figure 9. Pilot Choke
7
95
1
6
12
13
4
14
2
3
8
11
10
Part No. Part Name
1
2
3
4
5
6
7
Retaining Ring
Nut
Adjusting Screw
‘‘O’’ Ring
Back-up Ring
Needle Housing
‘‘O’’ Ring
Part No. Part Name
8
9
10
11
12
13
14
Back-up Ring
Needle
Spring
Sleeve
Body
Dowel Pin
‘‘O’’ Ring

12
3. Reducer Module (Fig 10): The reducer module is
required for Air Gap and Wet Armature piloted models when
pilot pressure exceeds 210 bar (3000 psi). These two-stage
spool valves maintain a reduced outlet pressure against
variations in inlet pressure. These valves are able to act as
relief valves (at 50% of the maximum flow) to prevent excess
pressure being developed when an actuator is subject to a
reactive load.
4. Fast Response Option: Some applications require the
main stage spool to shift at a faster than normal rate. For
such applications, the fast response option is used. This
option requires the removal of an orifice plug within the main
stage body. When the orifice plug is removed, larger volumes
of fluid will enter the pilot valve section. When the pilot valve
shifts, the main stage spool responds at a faster rate. However,
this also generates transients that increase system shock.
For this reason, the fast response option is not recommended
when pilot pressures exceed 210 bar (3000 psi). Fast
response models have the letter ‘‘X’’ stamped into the unit
nameplate (i.e. DG5V-10-062**X-51). Table 2 compares
standard shift times to the fast response option. Figures 21
through 26 show the location of the orifice plugs that must be
removed for the fast response option.
1
2
543
7
6
8
9
11
10
12
13
14
16 15
17
Part No. Part Name
1
2
3
4
5
6
7
8
9
Plug
Back-up Ring
‘‘O’’ Ring
‘‘O’’ Ring
Spool
Body
Ball (2)
Spring Rest
Spring
Part No. Part Name
10
11
12
13
14
15
16
17
Spring Rest
‘‘O’’ Ring
Spring Housing
‘‘O’’ Ring
Adjuster Housing
Adjuster
Nut
Dowel Pin
Figure 10. Reducer Module
Table 2. Shift Response Times w/CETOP 3 Pilot (Fast Response option not available)
Valve Type Condition Pilot Pressure
10 bar (150 psi) Pilot Pressure 100 bar (1500 psi) Pilot Pressure 210 bar (3000 psi)
Voltage Voltage Voltage
‘‘AC’’ ‘‘DC’’ ‘‘AC’’ ‘‘DC’’ ‘‘AC’’ ‘‘DC’’
3–Position Spring Centered Pilot Pressure Applied
Shift from Center to Offset 50 mS 80 mS 45 mS 60 mS 35 mS 55 mS
2–Position Spring Offset Pilot Pressure Applied
Shift from Offset to Offset 200 mS 210 mS 90 mS 130 mS 75 mS 100 mS
3–Position Spring Centered Pilot Pressure Removed
Shift from Offset to Center 50
mS 75
mS50 mS 75
mS
50
mS 75
mS
2–Position Spring Offset Pilot Pressure Removed
Shift from Offset to Offset 50
mS 80
mS
50
mS 80
mS
50
mS 80
mS
Table 2. Shift Response Times w/CETOP 5 Pilot (Fast Response option not available for pilot pressures over 140 bar (2000 psi)
Valve Type Condition Pilot Pressure
10 bar (150 psi) Pilot Pressure 100 bar (1500 psi) Pilot Pressure 210 bar (3000 psi)
Voltage Voltage Voltage
‘‘AC’’ ‘‘DC’’ ‘‘AC’’ ‘‘DC’’ ‘‘AC’’ ‘‘DC’’
3–Position
Spring Centered Pilot Pressure Applied - Shift from Center to Offset (Standard/Fast Response) 50/50 mS 80/80 mS 45/25 mS 75/60 mS 37/NA mS 70/NA mS
2–Position
Spring Offset Pilot Pressure Applied - Shift from Offset to Offset (Standard/Fast Response) 185/175 mS 240/190 mS 85/70 mS 130/125 mS 50/NA mS 115/NA mS
3–Position Spring
Centered Pilot Pressure Removed - Shift from Offset to Center (Standard/Fast Response) 50 mS 80 mS50 mS 80 mS50 mS 80 mS
2–Position Spring
Offset Pilot Pressure Removed - Shift from Offset to Offset (Standard/Fast Response) 75 mS 110 mS50 mS 110 mS30/NA mS 110/NA mS
‘‘DC’’ pilot runs without arc suppression devices. If diodes or other devices are used, de–energize times will be longer.

13
Figure 11. DG5V10 with DG4S4-01 Pilot
Section IV - Pilot Valve Section
A. Spool Type - Pilot Valve Section
To maintain proper control, closed center pilot spools are
normally used in two stage valves. In most cases, a number
‘‘6’’ type pilot spool is used.
When a type ‘‘4’’ or ‘‘8’’ main stage spool is used, the letter
‘‘V’’ is inserted into the pilot valve model code.
B. Spool Positioning - Pilot Valve Section
Pilot spools are positioned within the valve by special spool
arrangements. The three basic pilot valve spool arrangements
are spring centered, spring offset and detents. The following
paragraphs (1 through 3) describe pilot spool arrangements.
1. Spring Centered: A spring and washer are installed at
each end of the pilot valve spool. The spring moves the
spool until the washer contacts the end of the valve body. In
the deenergized condition of the pilot valve, the spool is held
in center position within the body by the springs and washers.
2. Spring Offset: Spring offset models use one spring and
washer to return the pilot valve spool to an offset position. In
this model, a solenoid is completely removed from the spring
end of the pilot valve. Solenoid operating power is reduced
by the sacrifice of the center spool position.
3. Detents: A detent mechanism is installed on one or both
ends of the pilot valve spool. Detent valve solenoids can be
momentarily energized to the correct position and then power
may be removed from the solenoid. This reduces the input
control power below that of an offset model.
The detent(s) hold the pilot spool in the last position attained
until the opposite solenoid is energized. As in the offset
valve, solenoid power is reduced by the sacrifice of the
center spool position.
C. Methods of Control - Pilot Valve
The following pilot control methods are available for pilot
spool position.
Control Model Codes
Electrical Solenoid DG4S4-01, DG4V-3, DG4V-3S
1. Remote Pilot: Pilot valves, such as a DG3V3, are
available for use with a remote pilot source. This means that
a valve can be shifted from a remote pressure source by
other valves in the logic circuit. Refer to service parts
drawings listed in Table 1.
2. Electrical Solenoid Pilot Operation: Electrical solenoids
are attached to the pilot valve body. Internal push pins
connect the solenoid to the pilot spool. When the magnetic
field of solenoid ‘‘B’’ is energized, the solenoid armature
moves the push pin and shifts the pilot spool towards
solenoid ‘‘A’’ (see Figure 12a). When solenoid ‘‘A’’ is
energized, the pilot spool shifts toward solenoid ‘‘B’’ (see
Figure 12b). When both solenoids are de-energized, the pilot
spool shifts to center position (see Figure 12c).

14
Figure 12a. Flow Conditions
Pressure to ‘‘B’’ - ‘‘A’’ to Tank
Figure 12b. Flow Conditions
Pressure to ‘‘A’’ - ‘‘B’’ to Tank
Figure 12c. Flow Conditions
Flow Blocked (Center Condition #2 Spool)
CAUTION
DO NOT energize both (AC) solenoids
simultaneously. Sustained operation with both
solenoids energized will cause excessive
current in the coil and accelerates burnout.
A. Electrical Solenoid Types Available: Three basic
types of electrical solenoids exist: Wet armature, air gap and
high performance. The unit nameplate identifies the type of
solenoid being used. See the model code in Table 2. If a 50
or 51 design two stage valve is equipped with a DG4V-3 pilot
valve, the letter ‘‘M’’ is stamped into the nameplate (i.e.
DG5V-062*-*M-51). The letter ‘‘M’’ indicates an adapter plate
is used to provide the necessary DG4V-3 pilot valve
interface requirements.
B. Wet Armature Type Solenoids: Wet armature
solenoids are standard on DG4V-3, DG4S4-01-60, and
DG4V4-01 pilot valves only. Wet armature solenoids have
many design advantages over other types of solenoids.
Some advantages include cooler operation, static sealing
arrangements, immunity to moisture and greater burn-out
resistance.DG4V-3 and DG4S4-01* wet armature solenoids
are not serviced with individual parts. Service is provided by
replacing the entire core tube subassembly. Parts can be
removed, cleaned and seals replaced on ‘‘W3’’ type
solenoids.
C. Air Gap Solenoids: DG4S4-01 pilot valves are usually
equipped with air gap solenoids. Air gap solenoids are isolated
from system fluid and can be removed and replaced without
disturbing the system. A push pin and sliding seal couple the
solenoid to the valve spool (see Figures 13a and 13b).
E. Electrical Solenoid Voltage Requirement: Electrical
solenoids are available in various AC and DC voltage
ranges. The standard voltage and frequency range is 115V
AC, 60 Hz. Refer to parts and service drawings for units with
non-standard voltage ranges. Fifty (-50) and fifty-one (-51)
design units have the voltage and frequency range stamped
into the nameplate if other than standard. Ten (-10), twenty
(-20) and fifty-three (-53) design units use an identification
letter for the coil voltage and frequency.
F. Electrical Solenoid Ground Connections and Wiring
Housing: An electrical wiring housing with a 1/2”NPTF
thread connection is available on DG4V-3 and DG4S4-01
pilot valves. the wiring housing can be rotated 180from the
position shown in Figure 13a. Wire grounding screws are
provided for convenience.
Figure 13a. Typical DG4V-3(S)-A/B-FW-60
Terminal Box
Flying Lead
Coil
Manual Override Plunger
Wet Armature (Standard)
Push Pin
Core Tube
Solenoid
Coil
Pilot Spool
Body
G. Manual Override: each solenoid (electrical or air type)
has a manual override plunger to shift the pilot spool. This
feature allows a technician to shift the pilot spool when
electricity or air pressure is not available. Refer to Figures
13a or 13b. To operate the manual override feature, obtain a
small rod and push in on the plunger.

15
5. Accessories for Electrical Type Solenoids: The model
code (Table 2) indicates the type of accessories used on
directional valves. Obtain a parts and service drawing for
your particular model (see Table 1). Most accessories
pertain to the pilot section. The most common types of
accessories are discussed in the following paragraphs (A
through F).
A. Hazardous Location Solenoids: This type of is used
at locations where added protection from electrical shortage
failure is mandatory, the solenoid housing is designed to
completely enclose all wiring connections to the valve.
Hazardous location valves are underwriters approved Class
1, Group D or Class 2, Group E-F-G, for 155 and 230 volts,
60 Hz service.
B. Monitor (Limit) Switch Feature: The monitor switch
feature can be incorporate into a basic spring offset
directional valve. The switch monitors pilot valve spool
position and an be wired into control circuits. This permits
electrical interlocking of various hydraulic controlled motions
without resorting to external mechanical arrangements. The
monitor switch is a single pole, double throw contact
arrangement with ‘‘A’’-normally closed and ‘‘B’’- normally
open. Switch ratings are noted on installation drawing (Table
1). The monitor switch housing does not provide a manual
plunger for operation of the switch or valve.
C. Insta-Plug Connectors: Pilot valves can be supplied
with electrical connectors called insta-plugs. These
connectors allow quick disconnect of electrical power from
the valve. The following data pertains to the insta-plug feature:
PA- A prefix of PA in the model code indicates the
male plug section of the insta-plug feature is included
on the valve.
PB- A prefix of PB in the model code indicates
both the male plug and female receptacle are
included with the valve. the insta-plug feature is
available on both the DG4V-3 and DG4S4-01 series
directional valves.
Wiring Note
Connect white wires to ‘‘A’’ solenoid and black wires to
the ‘‘B’’ solenoid. Refer to parts drawing (Table 1) for
additional data.
D. Brad Harrison Connectors: Brad Harrison connectors
thread into the 1/2”NPTF opening in the wiring housing of a
DG4V-3 or a DG4S4-01 directional valve.
PA3- A prefix of PA3 in the model code indicates
the three pin male connector is included with the
valve.
PA5- A prefix of PA5 in the model code indicates
the five pin male connector is included with the valve.
Female Brad Harrison connectors are not available from
Vickers and must be supplied by the customer.
E. Solenoid Indicator Lights: Solenoid indicator lights are
available for installation on both the DG4V-3 and DG4S4-01
series directional valves. Indicator lights are connected
across the solenoids and will light when voltage is present at
the solenoid. This gives an indication to the technician which
solenoid is energized and aids in troubleshooting a system.
Refer to the appropriate parts drawing for additional
information.
Fi
g
ure 13b. T
y
pical DG4V4-01-C-10
Pilot Spool
Body Terminal Box
Push Pin Spring
Core Tube Spool Stop
Plug-in
Coil
Manual override plunger
Section V - Internal Valve Functions
A. General
To insure the proper application of a two stage valve, pilot
pressure, pilot drain and integral check valve options must
be considered. The following paragraphs (B through D)
discuss these options.
B. Pilot Pressure
1. Internal Pilot Pressure (Standard): Internal pilot pressure
can be obtained in two ways and must be tailored for the
application. Models with closed center type spools
automatically provide internal pilot pressure. Models that use
open center spools require a check valve in the pressure (P)
port to maintain minimum pilot pressure. In most cases,
maximum internal pilot pressure is rated to 210 bar
maximum (3000 PSI). Minimum pilot pressure ratings are
noted in the installation drawings (see Table 1).
2. External Pilot Pressure: When pilot pressure from a
separate source is used, it must be connected to the ‘‘X’’ port
(external pilot pressure connection). Models that use
external pilot pressure do not require a check valve at the
pressure port. External pilot pressure models are identified
with the letter ‘‘E’’ stamped in the unit nameplate (i.e.
DG5V-10-S-2C-*-E-M-*-10). See installation drawings for
maximum external pilot pressure.

16
3. Pilot Pressure Conversions: If it is necessary to convert
your unit from external pilot pressure to internal pilot
pressure or vice versa, internal plug(s) must be removed or
added to the main stage body. See the figures noted in
installation plug tables for internal plug locations.
4. Pressure Centered ‘‘D’’ Models (H06 & -10 Series only):
A pre-set pilot pressure can be obtained in these models.
Refer to the model code in Table 2 for pressure settings.
Pilot pressure can be increased or decreased by simply
changing internal plugs in the main stage body. Refer to plug
table in parts drawing for part numbers and see the figures
noted in installation plug tables for internal plug locations.
C. Pilot Valve Drains
1. Internal Drain: Internal drain models are used when
pressure surges in the tank line are small and CAN NOT
overcome pilot pressure.
To shift a pilot spool, pilot pressure must always exceed tank
pressure by a minimum amount. Figure 14 is an example
showing pilot pressure vs. tank pressure. Refer to the unit
installation drawing for minimum pressure ratings. Internal
pilot drain models have the letter ‘‘T’’ stamped on the unit
nameplate (i.e. DG5V-10-S-2C-*-T-M-*-10).
Note
A 10 bar (150 PSIG) nP must always be maintained to
shift closed center spools. A 5 bar (75 PSIG) nP must
always be maintained to shift open center pilot spools.
Figure 14. Pilot Valve-Internal Drain
–1000
–900
–800
–700
–600
–500
–400
–300
–200
–100
–0
150
PSIG
nP
Pilot Pressure (1000 PSIG)
Tank Line Pressure Surge (850 PSIG)
Tank Line Pressure (750 PSIG)
Note
This tank line pressure subtracts
from the applied pilot pressure.
2. External Drain (Standard): External drain models are
recommended if pressure surges in the tank line CAN
overcome pilot pressure. Drain connection ‘‘Y’’ is used for
externally drained models. Pressure centered ‘‘D’’ models
use two drain connections ‘‘Y’’ and ‘‘W’’. All external drain
connections MUST be piped directly to tank through surge
free lines. Refer to the installation drawing (Table 1) for
further information.
3. Drain Conversions: If it is necessary to convert your unit
from external drain to internal drain or vice versa, an internal
‘‘T’’ plug must be added or removed to the main body
section.
D. Integral Check Valves
Check valves are located within the pressure port of the
main stage section. The purpose of the check valve is to
develop back pressure, at the pressure port, when open
center or tandem main stage spools are used. Back
pressure is necessary to maintain internal pilot pressure
when the main stage spool shifts to open center position.
Table 3 indicates when an integral check valve is required.
Pilot
Pressure Source Integral Check
Valve Required Main Stage Spool Type
Internal Yes 0, 1, 4, 8, 9, 11
No 2, 3, 6, 31, 33
External No All spools
Table 3. Integral Check Valve Circuit Requirements
Integral check valves are available at various cracking
pressure ranges. The unit nameplate identifies which check
valve is used (i.e. DG5V-10-S-2C-*-T-M-*-10). Refer to
installation drawing (Table 1) for additional check valve
information.
Note
As an alternate to the integral check valve, a 3.5/5 bar
(50/75 PSI) check valve can be installed in the tank line
of the valve to obtain pilot pressure.
Section VI - Installation
A. Service Drawings
The service drawings listed in Table 1 show installation
dimensions, port locations and operating parameters.
Manifold, subplate and bolt kit information is also included.
Note
Detent valves must be installed with the valve spool in
the horizontal position for good machine reliability. The
mounting position of spring offset and spring centered
models is unrestricted.

17
Note
Make sure the ‘‘Y’’ drain port is piped directly to the tank.
Back pressure cannot be tolerated at this valve port.
CAUTION
On solenoid operated directional valves, ensure
an electrical ground is connected to the valve.
This prevents the possibility of a shock hazard
if a coil develops a short circuit to the frame.
B. Fluids and Seals
Standard seals (Nitrile) can be used with petroleum,
water-glycols, and water-oil emulsion type fluids.
F1 seals (Butyl, EPR) must be used for alkyl
phosphate-ester base fluids and aircraft type fire-resistant
fluids. F1 seals cannot be used with petroleum or phosphate
ester-hydrocarbon blends.
F3 seals (Viton) can be used with all commonly used
industrial hydraulic fluids. Vitonis compatible with
petroleum, water-base and synthetic fire-resistant fluids.
Viton is a registered trademark of E.I. Dupont
F6 seals (Nitrile) can be used with petroleum, water-glycols,
and water-oil emulsion type fluids.
The following table summarizes the compatibilities of the
most common phosphate ester fluids.
Fluid Type F1 F3 F6
Skydrol Yes No No
Pydraul 10-E Yes No No
Pydraul 29-E-L-T, 50-E
65-E, 115-E Yes Yes Yes
Pydraul 230-C, 312-C,
540-C No Yes Yes
Fyrquel & Fyrlube Yes Yes Yes
Fyrtek No Yes Yes
Houghton Safe 1000 Series Yes Yes Yes
C. Piping and Tubing
1. All pipes and tubing must be thoroughly cleaned before
installation. Recommended cleaning methods are
sandblasting, wire brushing and pickling.
2. To minimize flow resistance and the possibility of external
leakage, use only the necessary fittings and connections
required for proper installation.
3. The number of bends in tubing should be kept to a
minimum to prevent excessive turbulence and friction of fluid
flow. Tubing must not be bent too sharply. The recommended
radius for tube ends is three times the inside diameter.
D. Hydraulic Fluid Recommendations
Hydraulic fluid within the systems performs the dual function
of lubrication and transmission of power. To insure proper
lubrication, system life, and component reliability, fluid
selection should be made carefully with the assistance of a
reputable supplier. Fluid selection should be acceptable for
use with all valves, motors and pumps within the system.
The fluid recommendations noted in the data sheet are
based on our experience in industry as a hydraulic
component supplier. Where special considerations indicate a
need to depart from these recommendations, see your
Vickers sales representative.
E. Cleanliness
To ensure your hydraulic system is clean, perform the
following steps:
Clean (flush) the entire system to remove paint, metal
chips, welding shot, etc.
Filter each oil change to prevent introduction of
contaminants.
Provide continuous oil filtration to remove sludge,
products of wear and corrosion generated during the life
of the system.
Provide protection to all areas that can introduce
airborne contaminants into the system.
Perform regular servicing procedures of filters, breathers,
and reservoirs.
F. Overload Protection
A relief valve must be installed in the system as close to the
pump as possible. the relief valve limits pressure in the
system to a prescribed maximum. The setting of the relief
valve depends on the work requirements of the system.

18
Section VII - Service, Inspection & Maintenance
A. Service Tools
No special tools are required to service this valve series.
B. Inspection
Periodic inspection of the fluid condition and tube or piping
connections can save time consuming breakdown and
unnecessary parts replacement. the following should be
checked regularly.
1. All hydraulic connections must be kept tight. A loose
connection in a pressure line will permit the fluid to leak
out. If the fluid level becomes so low as to uncover the
inlet pipe opening in the reservoir, extensive damage to
the system can result. Loose connections also permit air
to be drawn into the system resulting in a noisy and/or
erratic operation.
2. Clean fluid is the best insurance for long service life.
Therefore, check the reservoir periodically for dirt and
other contaminants. If the fluid becomes contaminated,
flush the entire system and add new fluid.
3. Filter elements should also be checked periodically. A
clogged filter element will cause higher pressure drops
within the system.
4. Air bubbles in the reservoir can ruin the valve and other
components. If bubbles are seen, locate the source of
the air and seal the leak.
C. Adding Fluid to the System
When hydraulic fluid is added to replenish the system, pour it
through a fine wire screen (200 mesh or finer). When
applicable, pump the fluid through a 10 micron filter. DO
NOT use a cloth to strain the fluid or lint may enter the
system.
D. Adjustments
No periodic adjustments are required other than normal
system maintenance,
E. Replacement Parts
Reliable operation throughout the specified operating range
is assured only if genuine Vickers parts are used.
Sophisticated design processes and material are used in the
manufacture of our parts. Substitutions may result in early
failure. Part numbers are shown in the parts and service
drawings listed in Table 1.
F. Product Life
The service life of this product is dependent upon
environment, duty cycle, operating parameters and system
cleanliness. Since these parameters vary from application to
application, the ultimate user must determine and establish
the periodic maintenance required to maximize life and
detect potential component failure.
G. Troubleshooting
Table 4 lists the common difficulties experienced with
directional valves and systems. It also indicates the probable
causes and remedies for each of the troubles listed.
Also remember that many apparent failures may actually be
the failure of other parts of the system. The cause of
improper operation is best diagnosed with adequate testing
equipment and a thorough understanding of the complete
hydraulic system.
TROUBLE PROBABLE CAUSE REMEDY
Valve spool fails to move Dirt in system Disassemble, clean and flush.
Solenoids inoperative Check electrical source and solenoids.
Improper assembly Check proper assembly. Refer to appropriate figure
and assembly procedure.
Improper installation connections Check installation drawings
Valve produces undesirable response Improper valve assembly
Improper installation connections Checks parts drawing and installation drawing for proper assembly and installation connections
Solenoid wiring reversed Reverse connections to the solenoids
Table 4. Troubleshooting Chart

19
Section VIII - Overhaul
WARNING
Before breaking a circuit connection, ensure
system power is off and system pressure has
been relieved. Lower all vertical cylinders,
discharge accumulators and block any load
whose movement could generate pressure. Plug all units
and cap all lines to prevent entry of dirt into the unit or
system.
A. Unit Removal
1. Thoroughly clean the exterior of the valve and the area
around the valve to prevent contamination of the system
during removal.
2. Remove the valve from its subplate or mounting pad as
follows:
A. If the valve is equipped with the insta-plug feature,
loosen the two slotted screws and unplug the electrical
wiring from the pilot section.
B. If the valve has an air operated section, turn off air
supply and disconnect the pressure lines from the
connection plate.
WARNING
In the following step make sure electrical
power is off, then disconnect the solenoid
wiring. Label each wire to provide assembly
information.
C. If the valve has standard electrically operated
solenoids, remove the four nameplate screws on top of
the pilot section. Move nameplate and gasket aside to
expose interior of the wire cavity. Disconnect solenoid
wiring.
D. Loosen the six mounting screws that hold the main
stage section to the mounting pad. Be ready to catch the
fluid retained inside the lines and valve.
E. Remove the valve from the mounting pad and set it
on a clean work bench. Use a chain lift when necessary.
B. Disassembly (General)
The manual describes the disassembly sequence of a typical
DG5V-10 two-stage directional valve. See Figures 15 and 17.
Slight variations may be noted on your model depending on
the type of accessories and unit design. Figure 15 may be
used for all models, except pressure centered ‘‘D’’ models
regardless of the design. Refer to Section E and Figure 17
for pressure centered ‘‘D’’ models. Figure 18 shows the
disassembly sequence of a DG4V-3(S)-*A(L)/B(L)-FJ/FW-60
standard performance pilot valve. If your pilot valve is a
DG4S4-01, refer to Figure 19.
C. Pilot Valve and Module Removal
(Refer to Figure 15)
1. Remove four screws (1) and pilot valve (2), pilot choke (3),
and reducer (4) from main stage body (5).
2. Remove ‘‘O’’ rings (6) from pilot choke and reducer.
3. Remove four screws (7) and adapter plate (8) from body.
Note
The following section pertains to main stage
disassembly. If your unit does not require main stage
disassembly, omit the following section.
D. General Main Stage Disassembly
(Refer to Figure 15)
WARNING
Spring in end cover is under tension. Slowly
remove end cover screws alternatively to
avoid damge to equipment and injury to
personnel
Note
Repeat steps 1 and 2 for opposite side cover disassembly.
1. Loosen four end cover screws (10) from end cover (11).
Be ready to catch any oil trapped inside the unit. Remove
end cover from body and discard ‘‘O’’ ring (12).
Note
Spring and washer do not exist on floating type models
or on opposite side of spring offset ‘‘A’’ models.
2. Remove spring (13) and washer (14) from main stage
spool (15).
3. Remove main stage spool from body.
4. Turn body on its side and remove plugs (23) and ‘‘O’’
rings (16, 22, 24, and 25) from body. Discard ‘‘O’’ rings.
Note
DO NOT remove the internal plugs of body unless
inspection reveals a problem.
Refer to figures 21 thru 26 for internal plug locations.
5. Remove plugs (21) and ‘‘O’’ rings (26) from body.
Discard ‘‘O’’ rings.
If necessary, remove rest pins (27) with vise grip pliers.

20
Note
The following step pertains to integral check valve models
only. DO NOT remove check valve parts unless inspection
or unit operation indicates a check valve problem. If
check valve removal is necessary, perform step 8.
8. Select the correct screw listed in Table 7. Obtain a piece
of pipe or tubing with an inside diameter that is slightly
larger than the outside diameter of the seat. Also obtain a
flat washer. Remove seat (17), Figure 16, per instructions
noted in Figure 16. Remove poppet (18), spring (19), and
sleeve (20) from body.
Screw Dia./ Thread Type Screw Length
1.125–7 UNC–2B 76.2mm (3 in.)
Table 7. Screw Tabulation for Seat Removal
Figure 16. Check Valve Seat Removal
Note
Thread seat (17), then place tubing and washer over
seat area as shown. Thread the screw into seat.
Tighten the screw to remove seat.
Screw
Tubing
Washer
Seat (17)
(Figure 15)
E. Pressure Centered Main Stage Disassembly
(Refer to Figure 17)
1. Remove four screws (1) and name plate (2) from
crossover plate (4).
2. Remove four screws (3) and crossover plate from main
stage body (6).
3. Remove and discard two ‘‘O’’ rings (5) from crossover
plate.
Note
The following section pertains to main stage disassembly. If
your unit does not require main stage disassembly, omit
the following section.
4. Loosen four end cover screws (7) from end cover (8). Be
ready to catch any oil trapped inside the unit. Remove
end cover, spring (10) and discard ‘‘O’’ ring (9).
5. Remove sleeve (11) and piston (12) from main stage
spool (13).
6. Remove main stage spool from body.
7. Remove plug (14) and ‘‘O’’ ring (15) from cover. Discard
‘‘O’’ ring.
Note
Perform step 8 for opposite side cover disassembly. Note
that centering springs are different.
8. Loosen four end cover screws (16) from end cover (17).
Be ready to catch any oil trapped inside the unit. Remove
end cover, spring (19) and centering washer (20).
9. Turn the body on its side and remove plugs (23) and ‘‘O’’
rings (21 and 22) from body. Discard ‘‘O’’ rings.
Note
DO NOT remove the internal plugs of body unless
inspection reveals a problem.
Refer to figures 21 thru 26 for internal plug locations.
10.Remove plugs (25) and ‘‘O’’ rings (24) from body.
Discard ‘‘O’’ rings.
11. If necessary, remove rest pins (28) with vise grip pliers.