D633 and D634 Series Direct Drive
Servo-Proportional Control Valves
with integrated 24 V Electronics
ISO 4401 Size 03 and 05
2 MOOG • D633/634 Series
GENERAL
D!""#D!"$
D633 AND D634 SERIES SERVO CONTROL VALVES
The D633 and D634 Series are Direct Drive Valves (DDV) with
electric closed loop spool position control.
These valves are throttle valves for 3-, 4-, and 2x2-way
applications. They are suitable for electrohydraulic position,
velocity, pressure or force control systems including those with
high dynamic response requirements.
The spool drive device is a permanent magnet linear force motor
which can actively stroke the spool from its spring centered
position in both directions. This is an advantage compared with
proportional solenoids with one force direction only. The closed
loop spool position electronics and pulse width modulated
(PWM) drive electronics are integrated into the valve.
The integrated electronics of the valves is a new development
featuring SMD technology with pulse width modulated (PWM)
current output stage and requires a 24 VDC power supply.
The valve series described in this catalog have successfully
passed EMC tests required by EC Directive. Please refer to the
respective references in the electronics section.
Valves available with explosion protection to EN 50018 and
55019, class II 2G EExde B+H
2
T4, DMT 00 ATEX E 037, CE 0470
for D633 series and II 2G EExde B+H
2
T3, DMT 00 ATEX E 037,
CE 0470 for D634 series.
Note: Installation dimensions and electrical connection altered.
Special data sheet on request.
MOOG SERVO- AND PROPORTIONAL CONTROL VALVES
For over 25 years Moog has manufactured proportional control
valves with integrated electronics. During this time more than
150,000 valves have been delivered. These servo control valves
have been proven to provide reliable control including injection
and blow molding equipment, die casting machines, presses,
heavy industry equipment, paper and lumber processing and
other applications.
SECTION PAGE
General 2
Benefits and Function 3
General technical data, Symbols 4
General technical data, Electronics 5
Technical Data 7
Ordering Information 13
This catalog is for users with technical knowledge. To ensure
that all necessary characteristics for function and safety of the
system are given, the user has to check the suitability of the
products described herein. In case of doubt, please contact
Moog.
NOTICE
➢ Before installation of the valve into the system, the complete
hydraulic system must be flushed.
➢ Please read the notes in section “Electronics”, page 6.
Our quality management system conforms to DIN EN ISO 9001.
MOOG • D633/634 Series 3
BENEFITS AND FUNCTION
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OPERATIONAL BENEFITS OF DIRECT DRIVE SERVO VALVES (DDV)
➢ Directly driven by a permanent magnet linear force motor
with high force level
➢ No pilot oil flow required
➢ Pressure independent dynamic performance
➢ Low hysteresis and low threshold
➢ Low current consumption at and near hydraulic null
➢ Standardized spool position monitoring signal with low
residual ripple
➢ Electric null adjust
➢ With loss of supply voltage or broken cable or emergency
stop, the spool returns to its spring centered position
without passing a load move position.
D633 Series single stage
Servo Control Valve
Hydraulic symbol:
Symbol shown with electric supply on and
zero command signal.
DIRECT DRIVE VALVE (DDV) OPERATION
The position control loop for the spool with position transducer
and linear force motor is closed by the integrated electronics.
An electric signal corresponding to the desired spool position
is applied to the integrated electronics and produces a pulse
width modulated (PWM) current to drive the linear force motor.
An oscillator excites the spool position transducer (LVDT)
producing an electric signal proportional to spool position.
The demodulated spool position signal is compared with the
command signal, and the resulting spool position error causes
current in the force motor coil until the spool has moved to its
commanded position and the spool position error is reduced to
zero. The resulting spool position is thus proportional to the
command signal.
The linear force motor is a permanent magnet differential
motor. The permanent magnets provide part of the required
magnetic force. For the linear force motor the current needed
is considerably lower than would be required for a comparable
proportional solenoid.The linear force motor has a neutral mid-
position from which it generates force and stroke in both
directions. Force and stroke are proportional to current.
High spring stiffness and resulting centering force plus external
forces (i.e. flow forces, friction forces due to contamination)
must be overcome during out-stroking. During backstroking to
center position, the spring force adds to the motor force and
provides additional spool driving force which makes the valve
much less contamination sensitive. The linear force motor needs
very low current in the spring centered position.
Proportional solenoid systems require two solenoids with more
cabling for the same function. Another solution uses a single
solenoid, working against a spring. In case of current loss in the
solenoid, the spring drives the spool to the end position by
passing through a fully open position. This can lead to
uncontrolled load movements.
PERMANENT MAGNET LINEAR FORCE MOTOR OPERATION
Null adjust cover plug
Valve connector
Spool
Integrated electronics
Position transducer
Linear force motor
Centering spring
Bushing
Cable hole
Permanent magnets
Centering springs
Bearing
Coil
Armature
Plug
4 MOOG • D633/634 Series
GENERAL TECHNICAL DATA,
SYMBOLS
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PERFORMANCE SPECIFICATIONS FOR STANDARD MODELS
Operating pressure range
Ports P, A and B up to 350 bar (5000 psi)
Port T see data for individual series
Temperature range
Ambient –20 °C to +60 °C (-4°F to +140°F)
Fluid –20 °C to +80 °C (-4°F to +170°F)
Seal material NBR, FPM,
others on request
Operating fluid mineral oil based hydraulic
fluid (DIN 51524, part 1 to 3),
others on request
Viscosity recommended 15 to 100 mm
2
/s
allowed 5 to 400 mm
2
/s
System filtration
High pressure filter (without bypass, but with dirt alarm)
mounted in the main flow and if possible directly upstream of
the valve.
Class of cleanliness
The cleanliness of the hydraulic fluid particularly effects the
performance (spool positioning, high resolution) and wear
(metering edges, pressure gain, leakage) of the servo valve.
Recommended cleanliness class
For normal operation ISO 4406 < 15 / 12
For longer life (wear) ISO 4406 < 14 / 11
Filter rating recommended
For normal operation ß
10
≥ 75 (10 µm absolute)
For longer life (wear) ß
6
≥ 75 ( 6 µm absolute)
Installation options any position,
fixed or movable
Vibration 30 g, 3 axes
Degree of protection EN60529: class IP 65 with
mating connector mounted
Shipping plate Delivered with an oil sealed
shipping plate
4-WAY FUNCTION
2X2-WAY FUNCTION
4-way version
spring centred
2x2-way version
(Y-Port required)
➢ Flow control (throttle valve) in port A
➢ Port Y required
➢ Connect externally port P with port B, and port A with
port T
➢ Flow control (throttle valve) in port A and port B
➢ Port Y required if pressure p
T
> 50 bar (715 psi) in port T
➢ for 3-way function close port A or port B of the manifold
➢ Spools with exact axis cut, 1,5 to 3 % or 10 % overlap
available
MOOG • D633/634 Series 5
GENERAL TECHNICAL DATA,
ELECTRONICS
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VALVE FLOW CALCULATIONS
The actual valve flow is dependent on the spool position and
the pressure drop across the spool lands.
At 100% command signal (i.e. +10 VDC = 100% valve opening),
the valve flow at rated pressure drop ∆p
N
= 35 bar per metering
land is the rated flow Q
N
. For other than rated pressure drop,
the valve flow changes at constant command signal according
to the square root function for sharp edged orifices.
Q [l/min] = calculated flow
Q
N
[l/min] = rated flow
∆p [bar] = actual valve pressure drop
∆p
N
[bar] = rated valve pressure drop
The real valve flow Q calculated in this way should result in an
average flow velocity in ports P, A, B or T of less than 30 m/s.
Valve pressure drop ∆p
[bar]
Flow rate Q [l/min]
∆p
max
= 350 bar (5000 psi)
➢ EMC: Meets the requirements of
emission: EN55011:1998+A1:1999 (limit class: B) and
immunity: EN61000-6-2:1999
➢ Minimum cross-section of all leads ≥ 0.75 mm
2
(0.001 in
2
).
Consider voltage losses between cabinet and valve.
➢ Note: When making electric connections to the valve (shield,
protective earth), appropriate measures must be taken to
ensure that locally different earth potentials do not result in
excessive ground currents. See also Moog Application Note
TN 353.
➢ Supply 24 VDC, min. 19 VDC, max. 32 VDC
Current consumption I
Amax
for D633 1.2 A
for D634 2.2 A
External fuse per valve for D633 1.6 A (slow)
for D634 2.5 A (slow)
➢ All signal lines, also those of external transducers, shielded.
➢ Shielding connected radially to ⊥ (0 V), power supply side,
and connected to the mating connector housing (EMC).
GENERAL REQUIREMENTS FOR VALVE ELECTRONICS
6 MOOG • D633/634 Series
ELECTRONICS
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WIRING FOR VALVES WITH 6+PE CONNECTOR
to EN 175201 Part 804
1
) and mating connector (type R and S, metal shell) with leading protective earth connection ().
See also Application Note AM 426 E.
VALVE ELECTRONICS WITH 24 VOLT SUPPLY VOLTAGE AND 6+PE POLE CONNECTOR
Command signal 0 to ±10 mA
floating, Valves with current command input
The spool stroke of the valve is proportional to I
D
= –I
E
.
100 % valve opening P ➧ A and B ➧ T is achieved at
I
D
= +10 mA. At 0 mA command the spool is in centered position.
The input pins D and E are inverting. Either pin D or E is used
according to the required operating direction. The other pin is
connected to signal ground at cabinet side.
Command signal 0 to ±10 V,
Valves with voltage command input
The spool stroke of the valve is proportional to (U
D
– U
E
).
100% valve opening P ➧ A and B ➧ T is achieved at
(U
D
– U
E
) = +10 V.
At 0 V command the spool is in centered position. The input
stage is a differential amplifier. If only one command signal is
available, pin D or E is connected to signal ground at cabinet
side according to the required operating direction.
Actual value 4 to 20 mA
The actual spool position value can be measured at pin F (see
diagram below). This signal can be used for monitoring and
fault detection purposes.
The spool stroke range corresponds to 4 to 20 mA.
The centered position is at 12 mA. 20 mA corresponds to 100%
valve opening P ➧ A and B ➧ T . The position signal output 4 to
20 mA allows detecting a cable break when I
F
= 0 mA.
Circuit diagram for measurement of actual value I
F
(position of spool) for valves with 6+PE pole connector
For failure detection purposes, it is advised to connect pin F
of the mating connector and route this signal to the control
cabinet.
Valve side
I
out
R
L
=500 Ω (0,25 W)
U
out
4-20 mA
Actual value
U
Out
: 2-10 V
Valve Connector
Mating
connector
Cabinet side
1
) formerly DIN 43563
Output actual value
spool position
Input rated command
(differential)
Not used
Supply / Signal Ground
⊥ (0 V)
CurrentCommandFunction Voltage Command
Supply
24 VDC (19 t0 32 VDC)
I
F-B
: = 4 to 20 mA. At 12 mA spool is in centered position.
R
L
=300 to 500Ω
Protective earth
(R
e
=200 Ω)
Input command I
D
=-
I
E
: 0 to ±10 mA
Input command (inv.) I
E
=-I
D
: 0 to ±10 mA
U
D-E
= 0 to ±10 V
R
e
= 10 kΩ
Input voltage for U
D-B
and U
E-B
for both signal types is limited to
min. -15 V and max. +24 V
MOOG • D633/634 Series 7
TECHNICAL DATA
D!""
Model . . . Type
Mounting pattern with or without leakage port Y
3
)
Port diameter
Valve version
2
)
Spool actuation
Pilot supply
Mass
Rated flow (±10%) at ∆p
N
= 35 bar [500 psi] per land
Max. valve flow
Operating pressure max.
Ports P,A,B
Port T without Y
Port T with Y
Port Y
Response time for 0 to 100% stroke, typical
Threshold
1
)
Hysteresis
1
)
Null shift
1
) with ∆T = 55 K
Null leakage flow
1
) max. (axis cut)
D633
ISO 4401-03-03-0-94
7.9 (0.31)
Single stage, spool in bushing
3-way, 4-way, 2x2-way
directly, with permanent magnet
linear force motor
none
2.5 (5.5)
5 / 10 / 20 / 40 (1.3 / 2.6 / 5.3 / 10.6)
75 (19.8)
350 (5000)
50 (715)
350 (5000)
directly to tank
≤ 12
< 0.1
< 0.2
< 1.5
0.15 / 0.3 / 0.6 / 1.2 (0.04 / 0.08 / 0.16 / 0.32)
mm (in)
kg (Ib)
l/min (gpm)
l/min (gpm)
bar (psi)
bar (psi)
bar (psi)
bar (psi)
ms
%
%
%
l/min (gpm)
1) At operating pressure p
p
= 140 bar (2000psi), fluid viscosity of 32 mm
2
/s (0.05 in
2
/s) and fluid temperature of 40 °C (104° F)
2) See symbols page 4
3) Leakage port Y must be used
➢ with 3- and 4-way function and p
T
> 50 bar (715psi)
➢ with 2x2-way function
PERFORMANCE SPECIFICATIONS FOR STANDARD MODELS
8 MOOG • D633/634 Series
TECHNICAL DATA
D!""
CHARACTERISTIC CURVES (TYPICAL)
Flow rate Q l/min [gpm]
100 [26.3]
200 [52.8]
150 [39.6]
80 [21.1]
60 [15.8]
40 [10.6]
30 [7.9]
15 [4.0]
10 [2.6]
8 [2.1]
6 [1.6]
4 [1.1]
3 [.79]
2 [.53]
6 [.26]
20 [5.3]
Valve pressure ∆p bar [psi]
10 20 30 50 70 100 150 200 350
[145] [290] [435] [725] [1015][1450][2175][2900][5076]
MOOG • D633/634 Series 9
TECHNICAL DATA
D!""
INSTALLATION DRAWING
–
–
–
–
Mounting pattern
ISO 4401-03-03-0-94, without X port
1
) Port X must not be drilled, not sealed at valve base.
Mounting surface needs flat within 0,01 mm (0.0004 in) over a distance of 100 mm (3.94 in). Average surface finish value, Ra = 0.8 µm.
mm
inch
PABTX
1)
F
1
F
2
GF
3
F
4
Y
21,5x 12,7 30,2 21,5 0 40,5 3340,5 040,5
25,9y 15,5 15,5 5,1 0 -0,75 31,7531,75 319
Ø7,5 Ø7,5 Ø7,5 Ø7,5 M5 M5 4M5 M5Ø3,3
PABTX
1)
F
1
F
2
GF
3
F
4
Y
0.85x 0.50 1.19 0.85 0 1.60 1.301.60 01.60
1.02y 0.61 0.61 0.20 0 -0.03 1.251.25 1.220.35
Ø0.30 Ø0.30 Ø0.30Ø0.30 M5 M5 0.16M5 M5Ø0.13
Spare parts and Accessories
10 MOOG • D633/634 Series
TECHNICAL DATA
D!"$
1) At operating pressure p
p
= 140 bar (2000 psi), fluid viscosity of 32 mm
2
/s (0.05 in
2
/s) and fluid temperature of 40 °C (104° F)
2) See symbols page 4
3) Leakage port Y must be used
➢ with 3- and 4-way function and p
T
> 50 bar (715 psi)
➢ with 2x2-way function
Model . . . Type
Mounting pattern with or without leakage port Y
3
)
Port diameter
Valve version
2
)
Spool actuation
Pilot supply
Mass
Rated flow (±10%) at ∆p
N
= 35 [500 psi] bar per land
Max. valve flow
Operating pressure max.
Ports P,A,B
Port T without Y
Port T with Y
Port Y
Response time for 0 to 100% stroke, typical
Threshold
1
)
Hysteresis
1
)
Null shift
1
) with ∆T = 55 K
Null leakage flow
1
) max. (axis cut)
D634
ISO 4401-05-05-0-94
11.5 (0.45)
Single stage, spool in bushing
3-way, 4-way, 2x2-way
directly, with permanent magnet
linear force motor
none
6.3 (13.9)
60 / 100 (15.8 / 26.3)
185 (48.8)
350 (5000)
50 (715)
350 (5000)
directly to tank
≤ 20
< 0.1
< 0.2
< 1.5
1.2 / 2.0 (0.26 / 0.43)
mm (in)
kg (Ib)
l/min (gpm)
l/min (gpm)
bar (psi)
bar (psi)
bar (psi)
bar (psi)
ms
%
%
%
l/min (gpm)
PERFORMANCE SPECIFICATIONS FOR STANDARD MODELS
MOOG • D633/634 Series 11
TECHNICAL DATA
D!"$
CHARACTERISTIC CURVES (TYPICAL)
Flow rate Q l/min [gpm]
100 [26.3]
200 [52.8]
150 [39.6]
80 [21.1]
60 [15.8]
40 [10.6]
30 [7.9]
15 [4.0]
10 [2.6]
8 [2.1]
6 [1.6]
4 [1.1]
3 [.79]
2 [.53]
6 [.26]
20 [5.3]
Valve pressure ∆p bar [psi]
10 20 30 50 70 100 150 200 350
[145] [290] [435] [725] [1015][1450][2175][2900][5076]
Mounting pattern
ISO 4401-05-05-0-94, without X port
1
) Port X must not be drilled, not sealed at valve base.
Mounting surface needs flat within 0,01 mm (0.0004 in) over a distance of 100 mm (3.94 in). Average surface finish value, Ra = 0.8 µm.
12 MOOG • D633/634 Series
TECHNICAL DATA
D!"$
INSTALLATION DRAWING
mm
inch
PABTT
2
YF
1
F
4
F
2
F
3
X
1)
27x 16,7 37,3 3,2 50,8 62 0 054 54
6,3y 21,4 21,4 32,5 32,5 11 0 46046
Ø11,2 Ø11,2 Ø11,2 Ø11,2 Ø11,2 Ø 6,3 M6 M6M6 M6
PABTT
2
YF
1
F
4
F
2
F
3
X
1)
1.06x 0.66 1.47 0.13 2.00 2.44 0 02.13 2.13
0.25y 0.84 0.84 1.28 1.28 0.43 0 1.810 1.81
Ø0.44 Ø0.44 Ø0.44 Ø0.44 Ø0.44 Ø 0.25 M6 M6M6 M6
–
–
–
–
–
–
–
–
–
–
Spare parts and Accessories
MOOG • D633/634 Series 13
ORDERING INFORMATION
D!""#D!"$
D 63... . .. .. ..........
Size 03
Series
3
24 VDC (19 to 32 VDC)
Supply voltage
2
6+PE pole EN 175201 Part 804
Valve connector
S
NBR (Buna)
Seal material
N
mid position
Spool position without electric supply
M
Standard D633
SeriesLinear motor
1
4-way: axis cut, linear characteristic
Bushing / Spool type
0
4-way: 1,5 to 3% overlap, linear characteristicA
4-way: 10% overlap, linear characteristicD
Standard D6342
P ➧ B, A ➧ T connected (10% open)F
2x2-way: P ➧ A, B ➧ T, with Y-port onlyZ
Special spool on requestX
P ➧ A, B ➧ T connected (10% open)
other openings on request
D
closed with plug p
Tmax
= 50 bar (715 psi)
Y- port
0
open, with filter insert p > 50 bar (715 psi)3
FPM (Viton)
others on request
V
Command Output
Signals for 100% spool stroke*
±10 VDC +4 to +20 mA
±10 mA, floating +4 to +20 mA
deadband compensation on request
M
X
Specification-Status
Model designation
Factory identification
Valve version
Preseries specificationE
Series specification-
explosion proof version
upon request
K
Special specification
assigned at the factory
Z
with integrated electronics
Rated flow
02
Q
N
[l/min] at ∆p
N
= 35 bar ∆p
N
= 5 bar per land
(Q
N
[gpm] at ∆p
N
= 500 psi)
5 2 D633
04 10 4 D633
08 20 8 D633
16 40 16 D633
24 60 24 D634
40 100
(1.3)
(2.6)
(5.3)
(10.6)
(15.8)
(26.3) 40 D634
Series
R
Maximum operating pressure
350 bar (5000 psi)K
Size 054
Model-Number Type designation
*(input voltage limited, see page 6)
ORDERING INFORMATION
Options may increase price and delivery.
All combinations may not be available.
Preferred configurations are highlighted.
Technical changes are reserved.
14 MOOG • D633/634 Series
NOTES
D!""#D!"$
MOOG • D633/634 Series 15
NOTES
D!""#D!"$
Argentina
Australia
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Finland
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Germany
India
Moog Inc., East Aurora, NY 14052-0018
Telephone: 716/655-3000
Fax: 716/655-1803
Toll Free: 1-800-272-MOOG
www.moog.com
CDL6581 Rev F 500-189 103
Industrial Controls Division
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