WHAT MOVES YOUR WORLD
HIGH PERFORMANCE, TWO-STAGE DESIGN PROVIDING
FLOW CONTROL IN A SIMPLE, RUGGED, DEPENDABLE,
LONGLIFE DESIGN
Rev. P, March 2024
SERVO VALVES
PILOT OPERATED
FLOW CONTROL VALVE
WITH ANALOG INTERFACE
78 SERIES
2Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
Whenever the highest levels of motion control
performance and design flexibility are required, you’ll find
Moog expertise at work. Through collaboration, creativity
and world-class technological solutions, we help you
overcome your toughest engineering obstacles, enhance
your machine’s performance, and help take your thinking
further than you ever thought possible.
This catalog is for users with technical knowledge. To ensure all necessary characteristics for function and safety of the system, the user has to check the suitability of the products
described herein. The products described in this document are subject to change without notice. In case of doubt, please contact Moog.
Moog is a registered trademark of Moog Inc. and its subsidiaries. All trademarks as indicated herein are the property of Moog Inc. and its subsidiaries. For the full disclaimer refer to
www.moog.com/literature/disclaimers.
For the most current information, visit www.moog.com/industrial or contact your local Moog office.
INTRODUCTION
INTRODUCTION ..........................................................................2
Product Overview ..............................................................3
Features and Benefits......................................................4
Description of Operation...............................................5
TECHNICAL DATA .....................................................................6
78 Series - Standard Response Version.................6
78 Series - High Response Version..........................8
Installation Drawing..........................................................10
Mounting Requirements..................................................11
Electrical Connection.......................................................12
BACKGROUND ............................................................................13
Flow Calculation..................................................................13
Null Cut Options.................................................................13
Related Products................................................................14
About Moog...........................................................................15
ORDERING INFORMATION.....................................................17
Accessories and Spare Parts ....................................... 17
Ordering Code .....................................................................18
3Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
The 78 series is part of the Moog family of Mechanical
Feedback (MFB) Servo Valves. They are throttle valves
for 3 and 4 way applications. This series has a high
performance, two-stage design that covers a range of
rated flows from 75 to 150 l/min (20 to 40 gpm) at 35
bar (500 psi) valve drop per spool land. These valves are
intended for position, speed, pressure or force control
applications that require high dynamic response. The 78
series MFB offers high dynamics, high resolution and low
hysteresis due to its low friction double nozzle pilot stage.
The design is simple and rugged for dependable, long
life operation. The output stage is a closed center, 4
way sliding spool. The pilot stage is comprised of a
symmetrical, double nozzle dry torque motor. The 2
nd
stage spool position is controlled by a carbide tipped
feedback wire. The carbide ball on the end of the feedback
wire is a mandatory design requirement that ensures high
accuracy, reliable operation and long service life. All of
our servo valves are known for high accuracy and reliable
operation even in the harshest industrial applications.
This family of valves is considered a flow control servo
valve with an analog interface, but does not contain
integrated electronics. The options in this series include
standard and high response, special null (spool) cuts,
seal materials and connectors. Intrinsically safe and
flameproof designs for use in hazardous environments are
also available with specific models certified to FM, ATEX,
CSA and TIIS (Asian) standards.
All of our valves are backed by Moog Global Support, our
promise to provide world-class repair and maintenance
services delivered by our trained technicians. Each
valve possesses a long life design, controlled by proven
servo valve technology that has an outstanding history
of 60 years of meeting the motion control needs of our
customers. All of this makes Moog servo valves the best
choice for your hydraulic motion control requirements.
INTRODUCTION
PRODUCT OVERVIEW
Intrinsically safe and explosion proof valve versions are available for use in potentially hazardous environments. Specific
models are certified to FM, ATEX, CSA, TIIS and IECEx standards. Contact Moog for details.
TIIS
Standard response valves
with Ø 0.625 spool
High response valves
with Ø 0.406 spool
Valve design 2-stage, with spool and bushing and dry torque motor
Mounting pattern Unique to 78 Series
Maximum operating pressure to ports P, T, A, B 210 bar (3000 psi)
Maximum flow 208 l/min (54.9 gpm) 156 l/min (41.2 gpm)
Pilot stage Nozzle Flapper
Rated flow at Δp
N
35 bar/spool land
(500 psi/spool land)
75 l/min
(20 gpm)
115 l/min
(30 gpm)
150 l/min
(40 gpm)
75 l/min
(20 gpm)
115 l/min
(30 gpm)
Step response time for 0 to 100 % stroke 30 ms 40 ms 15 ms 20 ms
4Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
INTRODUCTION
FEATURES AND BENEFITS
Features Benefits
100% factory tested to ensure critical specification
performance
Ensures smooth and easy startup, reduces downtime and
insures long life in critical industrial applications
2 Stage Design Enables high machine performance, faster cycle times and
greater accuracy - all resulting in higher productivity
Dual Coil torque motor Redundancy for high reliability
Dual Precision Nozzles in Torque Motor Precision flow control and predictability
Dry torque motor design Eliminates potential contamination issues in the air gaps
of the torque motor that could cause machine downtime
Hardened 440C Bushing and Spool Provides for high life, wear resistance when used in the
harsh environments; provides for low sliding friction
during use
Emergency failsafe positioning Most valves are set up to return to a failsafe position
when the command signal is interrupted or eliminated
Field replaceable pilot stage filter Enables preventive maintenance in the field, saving
precious machine downtime and service costs
External null bias adjustment Enables technicians to manually adjust the null bias of
the valve to adapt to the conditions of the machine.
This feature provides a simple adjustment to machine
performance without the need to adjust a controller.
The 78 Series is proven technology that performs
reliably in machines where high performance, stability
and accuracy are required. Moog’s Mechanical Feedback
Valves are designed to provide high reliability and long
service life. The current technology reflects over 60 years
of experience of servo control in some of the world’s most
demanding environments.
PRODUCT OVERVIEW
Documents
Name Description Remark Number
Catalog 78 series
T
o download document
click here or scan below:
CDL6272
Manual 78 standard series CDS6569
78 intrinsically safe (K) series CDS6752
78 explosion proof (N) series CDS6857
Installation drawing 78 standard series CC44555
78 instrinsically safe (K) series
78 explosion proof (N) series CC42165
CC42165
78 standard series
78 explosion proof (N) series
CC44555
5Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
INTRODUCTION
DESCRIPTION OF OPERATION
P
B
T
A
Spool
Feedback Wire
Nozzles
Lower Polepiece
Upper Polepiece
Inlet
Orifice
Flexure Tube
Coil
Armature
Connector
Bushing
Electro-hydraulic Servo Valve Cut-away
The 78 Series Flow Control Servo Valve consists of a
polarized electrical torque motor and two stages of
hydraulic power amplification. The torque motor armature
extends into the air gaps of the magnetic flux circuit and
is supported in this position by a flexure tube. The flexure
tube acts as a seal between the electromagnetic and
hydraulic sections of the valve. The 2 torque motor coils
surround the armature, one on each side of the flexure
tube.
The flapper of the first stage hydraulic amplifier is rigidly
attached to the midpoint of the armature. The flapper
extends through the flexure tube and passes between 2
nozzles, creating two variable orifices between the nozzle
tips and the flapper. The pilot pressure is controlled
by the flapper/nozzle variable orifice and is in turn fed
to the end areas of the second stage spool. This action
creates a differential pressure from one end of the spool
to the other and results in spool displacement. The spool
displacement causes a force in the feedback wire which
opposes the original input signal torque. Spool movement
continues until the feedback wire force equals the input
signal force.
The second stage is a conventional four-way spool design
in which output flow from the valve, at a fixed valve
pressure drop, is proportional to spool displacement from
the null position. A cantilever feedback spring is fixed to
the flapper and engages a slot at the center of the spool.
Displacement of the spool deflects the feedback spring
which creates a force on the armature/flapper assembly.
Input signal induces a magnetic charge in the armature
and causes a deflection of the armature and flapper. This
assembly pivots about the flexure tube and increases the
size of one nozzle orifice and decreases the size of the
other.
6Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
TECHNICAL DATA
78 SERIES - STANDARD RESPONSE VERSION
Sample deviation of rated flow ±10 %
Step response time for 0 to 100 % stroke 30 ms 30 ms 40 ms
Threshold 0.5 %
Hysteresis < 3.0 %
Null shift at ΔT = 38 °C (100 °F) < 2.0 %
General Technical Data
Hydraulic Data
Static and Dynamic Data
Maximum operating pressure to ports P, T, A, B 210 bar (3,000 psi)
Rated flow at Δp
N
35 bar/spool land
(500 psi/spool land)
75 l/min (20 gpm) 115 l/min (30 gpm) 150 l/min (40 gpm)
Maximum flow 208 l/min (54.9 gpm)
Null adjust authority Greater than 10 % of rated flow
Hydraulic fluid Hydraulic oil as per DIN 51524 parts 1 to 3 and ISO 11158.
Other fluids on request.
Temperature range -40 to +60 °C (-40 to +140 °F)
Recommended viscosity range 10 to 85 mm
2
/s (cSt)
Maximum permissible viscosity range 5 to 1250 mm
2
/s (cSt)
Recommended cleanliness class as per ISO 4406
For functional safety 17/14/11
For longer service life 15/13/10
Recommended filter rating
For functional safety β
10
= 75 (10 µm absolute)
For longer life β
5
= 75 (5 µm absolute)
Valve design 2-stage, with spool and bushing and dry torque motor
Pilot stage Nozzle Flapper
Mounting pattern Unique to 78 Series
Installation position Any orientation, fixed or movable
Weight 2.86 kg (6.3 lb)
Storage temperature range -40 to +60 °C (-40 to +140 °F)
Ambient temperature range -40 to +135 °C (-40 to +275 °F)
Vibration resistance 30 g, 3 axis, 10 Hz to 2 kHz
Shock resistance 30 g, 3 axis
Seal material Fluorocarbon (FKM) 85 Shore D
Others upon request
7Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
TECHNICAL DATA
78 SERIES - STANDARD RESPONSE VERSION
1
2
4
3
80
40
120
-4
+2
-8
-16
-12
0
0510 10050
-20
Decibals
Frequency (Hz)
Phase Lag (Degrees)
1
2
0
20
40
60
80
100
20
40
50
30
10
0
Stroke (% of Rated Signal)
Time (ms)
1
2
3
40
80
0
0510 10050
-4
+2
-8
-16
-12
-20
4
120
Phase La
g
(De
g
rees)
Frequency (Hz)
0
Decibals
Note: Measured with 210 bar (3,000 psi), DTE
®
-24 fluid at +38 °C (+100 °F)
0
20
30
10
10
5
15
25
20
30
35
1
2
40
50
Time (ms)
Stroke (% of Rated Signal)
Reduced Amplitude Step Response
33 % step
Plot 1 = 75/115 l/min (20/30 gpm)
Plot 2 = 150 l/min (40 gpm)
Standard Frequency Response
75/115 l/min (20/30 gpm)
Plot 1 & 3 = ±40 % rated signal
Plot 2 & 4 = ±100 % rated signal
Full Amplitude Step Response
100 % step
Plot 1 = 75/115 l/min (20/30 gpm)
Plot 2 = 150 l/min (40 gpm)
Standard Frequency Response
154 l/min (40 gpm)
Plot 1 & 3 = ±40 % rated signal
Plot 2 & 4 = ±100 % rated signal
8Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
TECHNICAL DATA
78 SERIES - HIGH RESPONSE VERSION
General Technical Data
Hydraulic Data
Static and Dynamic Data
Maximum operating pressure to ports P, T, A, B 210 bar (3,000 psi)
Rated flow at Δp
N
35 bar/spool land
(500 psi/spool land)
75 l/min (20 gpm) 115 l/min (30 gpm)
Maximum flow 156 l/min (41.2 gpm)
Null adjust authority Greater than 10 % of rated flow
Hydraulic fluid Hydraulic oil as per DIN 51524 parts 1 to 3 and ISO 11158.
Other fluids on request.
Temperature range -40 to +60 °C (-40 to +140 °F)
Recommended viscosity range 10 to 85 mm
2
/s (cSt)
Maximum permissible viscosity range 5 to 1250 mm
2
/s (cSt)
Recommended cleanliness class as per ISO 4406
For functional safety 17/14/11
For longer service life 15/13/10
Recommended filter rating
For functional safety β
10
= 75 (10 µm absolute)
For longer life β
5
= 75 (5 µm absolute)
Valve design 2-stage, with spool and bushing and dry torque motor
Pilot stage Nozzle Flapper
Mounting pattern Unique to 78 Series
Installation position Any orientation, fixed or movable
Weight 2.86 kg (6.3 lb)
Storage temperature range -40 to +60 °C (-40 to +140 °F)
Ambient temperature range -40 to +135 °C (-40 to +275 °F)
Vibration resistance 30 g, 3 axis, 10 Hz to 2 kHz
Shock resistance 30 g, 3 axis
Seal material Fluorocarbon (FKM) 85 Shore D
Others upon request
Sample deviation of rated flow ±10 %
Step response time for 0 to 100 % stroke 15 ms 20 ms
Threshold 0.5 %
Hysteresis < 3.0 %
Null shift at ΔT = 38 °C (100 °F) < 2.0 %
9Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
TECHNICAL DATA
78 SERIES - HIGH RESPONSE VERSION
0510 10050
-4
+2
-8
-16
-20
-12
0
1
2
4
3
80
40
120
Decibals
Frequency (Hz)
Phase Lag (Degrees)
1
2
0
20
40
50
30
10
0
20
40
60
80
100
Stroke (% of Rated Signal)
Time (ms)
0510 10050
-4
+2
-8
-16
-20
-12
0
1
2
4
3
80
40
120
Decibals
Frequency (Hz)
Phase Lag (Degrees)
Note: Measured with 210 bar (3,000 psi), DTE
®
-24 fluid at +38 °C (+100 °F)
10
25
35
20
5
0
15 30
0
5
15
10
30
35
25
20
1
2
Time (ms)
Stroke (% of Rated Signal)
Reduced Amplitude Step Response
33 % step
Plot 1 = 75 l/min (20 gpm)
Plot 2 = 115 l/min (30 gpm)
High Frequency Response
75 l/min (20 gpm)
Plot 1 & 3 = ±40 % rated signal
Plot 2 & 4 = ±100 % rated signal
Full Amplitude Step Response
100 % step
Plot 1 = 75 l/min (20 gpm)
Plot 2 = 115 l/min (30 gpm)
High Frequency Response
115 l/min (30 gpm)
Plot 1 & 3 = ±40 % rated signal
Plot 2 & 4 = ±100 % rated signal
10Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
TECHNICAL DATA
INSTALLATION DRAWING
Pin D
Pin A
Pin B Pin C
46.02
(1.812)
78.89 (3.11)
2.92 ±0.64 (0.115 ±0.025)
145.54 (5.73)
86.87
(3.42)
69.85
(2.75)
38.11 (1.50)
Ø 3.18 (0.125)
51.31
(2.02)
104.52
(4.12 )
76.20 (3.00)
30.15
(1.187)
18.90 (0.74)
72.77
(2.86)
53.72
(2.12)
61.72
(2.43)
46.02
(1.812)
30.15
(1.187)
1
2
5
7
6
3
4
Ø13.51
(0.532)
Note: Dimensions in mm (in)
1 Locating pin
2 Filter and plug location
3 Mechanical null adjust
4 Optional magnetic null adjust
5 Electrical connector (as shown, mates with
MS3106F14S-2S)
6 Filter
7 Filter plug
11Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
TECHNICAL DATA
MOUNTING REQUIREMENTS
Surface
Surface to which the valve is mounted requires:
• Flatness of 0.01 mm (0.004 in) over 100 mm (3.94 in)
• Average finish R
a
better than 0.8 μm (0.000032 in)
Ports
For maximum flow the ports must be designed as follows:
• P, T, A, and B must be designed with diameters of 16 mm
(0.625 in)
Designation Ports Locating
Pin
Mounting Holes
P A B T G F1 F2 F3 F4
Size Ø mm
in
15.88
0.625
15.88
0.625
15.88
0.625
15.88
0.625
3.96
0.156
M8
5/16-18
M8
5/16-18
M8
5/16-18
M8
5/16-18
Position X mm
in
46.02
1.812
68.25
2.687
23.80
0.937
46.02
1.812
66.65
2.624
0
0
92.08
3.625
92.08
3.625
0
0
Position Y mm
in
52.37
2.062
30.15
1.187
30.15
1.187
7.92
0.312
50.77
1.999
0
0
0
0
60.33
2.375
60.33
2.375
F4
T
A
P
B
G
Y
X
F3
F2
F1
Recommended Mounting Seals
• Material dependent on application
• 1.78 mm (0.070 in) cross section x 18.77 mm (0.739 in)
inside diameter. 90 durometer
• Equivalent AS83248/2 size -018
Recommended Mounting Screws
• Material dependent on application
• SHCS 5/16 x 3.0 long. Grade 8 minimum
• SHCS M8 x 75 long. Grade 10.9 minimum
12Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
TECHNICAL DATA
ELECTRICAL CONNECTION
Ordering code Command signal [mA] Coil
resistance
[Ohms/coil
at 25 °C (77
°F)]
Power consumption [W] Coil inductance [H]
measured at 50 Hz
Single
coil
Series
coil
Parallel
coil
Single
coil
Series
coil
Parallel
coil
Single
coil
Series
coil
Parallel
coil
L ±40 ±20 ±40 80 0.128 0.064 0.22 0.66 0.18
M ±50 ±25 ±50 80 0.20 0.10 0.22 0.66 0.18
Z ±200 ±100 ±200 22 0.88 0.44 0.07 0.21 0.06
Single Series Parallel
A B C D
A B C D
A B C D
A (+), B (-) or C (+), D (-) A (+), D (-), B and C connected A and C (+), B and D (-)
Rated Current and Coil Resistance
A variety of coils are available for 78 Series Servo Valves,
which offer a wide choice of rated currents.
Coil Impedance
The resistance and inductance of standard coils are
given below. The 2 coils in each Servo Valve are wound
with equal turns giving a normal production tolerance
on coil resistance of ±12 %. Copper magnet wire is
used, so the coil resistance will vary significantly with
temperature. The effects of coil resistance changes can be
essentially eliminated through use of a current feedback
servoamplifier having high output impedance.
Inductance is determined under pressurized
operating conditions and is greatly influenced by back
electromagnetic forces of the torque motor. These effects
vary with most operating conditions, and vary greatly
with signal frequencies above 100 Hz. The apparent coil
inductance values given are determined at 50 Hz.
Coil Connections
A 4-pin electrical connector that mates with an
MS3106F14S-2S is standard. All 4 torque motor leads are
available at the connector so that external connections
can be made for series, parallel, or differential operation.
Connection for valve opening P → B, A → T
13Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
FLOW CALCULATION
BACKGROUND
The actual flow is dependent upon electrical command
signal and valve pressure drop.The flow for a given valve
pressure drop can be calculated using the square root
function for sharp edge orifices.
Q =
Q
N
.
p
p
N
Q [l/min (gpm)] actual flow
Q
N
[l/min (gpm)] rated flow
∆p [bar(psi)] actual pressure drop per spool land
∆p
N
[bar(psi)] rated pressure drop per spool land
NULL CUT OPTIONS
•
•
•
35
(500)
70
(1,000)
140
(2,000)
210
(3,000)
280
(4,000)
14
(200)
150 (40)
115 (30)
75 (20)
38 (10)
19 (5)
189 (50)
303 (80)
227 (60)
150 (40)
115 (30)
75 (20)
∆p [bar (psi)]
Q [l/min (gpm)]
Flow diagram
Standard Axis Cut Underlapped Overlapped
Input Current
Control Flow
Q
I
Control Flow
Input Current
Q
I
Underlap
Zone
Minimal change in gain through null
region. Best overall preformance for
most closed loop systems.
Null region flow gain is higher than
normal. Always allows some small
amount of flow past the spool.
Null region flow gain is lower than
normal. Spool types can range from
minimal overlap to completely
blocked flow.
Input Current
Control Flow
Q
I
Overlap
Zone
14Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
BACKGROUND
RELATED PRODUCTS
DIN Rail Modules - Analog Control Cards
Moog’s DIN rail mounted module analog control cards
are ideal for use in enclosures where space is limited.
Modules include servoamplifers, transducer conditioning
electronics, command and auxilliary function modules,
valve drive amplifiers, and power supplies. All of these
modules are CE marked and require a 24 V
DC
supply. The
modules mount to standard 35 mm DIN rail mount for easy
installation and removal.
DIN Rail Module
Portable Valve Testers - Evaluates Valves in the
Field
Valve testers are a cost effective method for evaluating
valves in the field. They provide a quick and easy means of
differentiating between hydraulic and electronic problems.
There are five models to choose from, each with different
levels of capability and flexibility to meet your specific
requirements. All valve testers have a compact, easily
portable design.
Valve Tester
Mounting Manifolds - Easier Installation and
Maintenance
Various mountings manifolds are available for standard
industrial valves, including base and adapter types for
mounting and flushing requirements. Other hardware such
as bolts and connectors are also available.
The specific accessories you may need for a particular
model are listed in the relevant product catalogs and can
be ordered through your local office.
Mounting Manifolds
Filtration - Oil Filtration Requirements for
Industrial Servo Systems
The most effective way to reduce life cycle costs of
an oil hydraulic system is through close attention to
contamination control.
For industrial servo systems the ideal system filter
arrangement is summarized as follows:
• Use a 15 micron (Beta 15 ≥ 75) high pressure filter
without by-pass just before the valve or critical parts
of the valve (e.g. pilot)
• Use a 3 micron (Beta 3 ≥ 75) low pressure filter in the
return or bypass line.
• Use a filter in the tank breather that is at least the
same filtration level as the finest filter in the system.
This recommendation is based on the fact that most servo
and proportional valves can accept the odd particle up to
25 microns so the pressure filter will protect the valve
from catastrophic failure. The real work is done by the
low pressure filter reducing small particle contamination
which is the prime contributor to component wear and
silting.
Assuming that the filters are properly dimensioned and
care is taken during initial installation and maintenance,
the aim should be to limit oil contamination to 16/13
(under the old ISO 4406) or 19/16/13 (under the new
ISO 4406).
For long life, the maximum levels per the old and new ISO
are 15/12 and 18/15/12, respectively. It is important to
note that these are maximum contamination levels and
with proper care and regular filter change, significantly
lower levels can and should be achieved. Attention must
also be paid to a number of other factors that contribute
to oil condition problems such as elevated temperatures,
high tank humidity, “dirty” new oil.
15Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
ABOUT MOOG
BACKGROUND
Moog Inc. is a worldwide designer, manufacturer and
integrator of precision control components and systems.
Moog’s Industrial Group designs and manufactures
high performance motion control solutions combining
electric, hydraulic, and hybrid technologies with
expert consultative support in a range of applications
including energy production and generation machinery,
industrial production machinery and simulation and test
equipment. We help performance-driven companies
design and develop their next-generation machines. Moog
Industrial Group, with fiscal year 2011 sales of USD
629 million and over 40 locations worldwide, is part of
Moog Inc. (NYSE:MOG.A and MOG.B) which has sales of
USD 2.3 billion.
Moog maintains facilities in 26 countries around the globe.
This vast scope ensures that our engineers remain close
to the needs of machine builders and provide flexible
design solutions and technical expertise tailored to our
customers’ toughest challenges.
Moog experts work in close collaboration with machine
builders and application engineers to design motion
control systems for greater productivity, higher reliability,
superior connectivity, less costly maintenance and more
effective operations. Our regional presence, industry
knowledge and design flexibility ensures Moog motion
control solutions are tailored to their environment—
from meeting operating regulations and performance
standards, to taking machine performance to a higher
level.
Products
At the heart of every Moog solution is an array of products
engineered for precision, high performance and reliability.
For more than six decades, Moog products have been
specified for critical machine applications.
Some are developed specifically for unique operating
environments. Others are standard equipment on
machines across many industries. All are continuously
improved to take advantage of the latest technology
breakthroughs and advancements.
Moog products include:
• Servo Valves and Proportional Valves
• Servo Motors and Servo Drives
• Servo Controllers and Software
• Radial Piston Pumps
• Actuators
• Integrated Hydraulic Manifold Systems and Cartridge
Valves
• Slip Rings
• Motion Bases
Servo Valves
Active Cartridge Valves
Radial Piston Pumps
Servo Drives
16Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
ABOUT MOOG
Solutions
Hydraulic solutions
Since Bill Moog invented the first commercially viable
servo valve in 1951, Moog has set the standard for world-
class hydraulic technology. Today, Moog products are
used in a variety of applications - providing high power,
enhanced productivity and ever better performance for
some of the worlds most demanding applications.
Electric solutions
Clean operation, low noise generation, less maintenance
and reduced power consumption make Moog electric
solutions ideal for applications worldwide. Moog is
the ideal partner for applications where transitioning
technologies requires special expertise.
Hybrid solutions
By incorporating the advantages of existing hydraulic
and electric technologies - including modular flexibility,
increased efficiency and cleanliness - into innovative
hybrid solutions, Moog offers new performance potential
in specialized applications.
Flight Simulation
Formula One Simulation Table
Moog Global Support
Moog Global Support is our promise to offer world-class
Repair and Maintenance Services delivered expertly by our
trained technicians. With the reliability only available from
a leading manufacturer with facilities around the world,
Moog offers you service and expertise you can count on to
keep your equipment operating as it should.
This promise offers many benefits to our customers
including:
• Reduce your downtime by keeping critical machines
running in peak performance
• Protect your investment by ensuring reliability,
versatility and long-life of products
• Better plan your maintenance activities and make
systematic upgrades
• Leverage our flexible programs to meet the unique
service requirements of your facility
Look to Moog for global support including:
• Repair services using OEM parts are performed by
trained technicians to the latest specifications
• Stock management of spare parts and products to
prevent unplanned downtime
• Flexible programs, tailored to your needs such as
upgrades, preventative maintenance and annual/multi-
year contracts
• On-site services bring the expertise to you, providing
quicker commissioning, set-up and diagnostics
• Access to reliable services that are guaranteed to
offer consistent quality anywhere in the world
For more information on Moog Global Support visit
www.moog.com/industrial/service.
BACKGROUND
17Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
ORDERING INFORMATION
Part designation Description Material Part number
Maintenance kit Base o-rings FKM per AMS7259
Note that o-ring material is
dependent on application.
B52555RK052K001
Additional o-rings required for filter
access
Filter tube
ACCESSORIES AND SPARE PARTS
18Rev. P, March 2024
Moog 78 Series Flow Control Servo Valves
All combinations may not be available.
Preferred Models
Model number Type designation Rated flow
l/min gpm
Rated current
mA
-078-120D S07FOGM4VBL 75 20 ± 40
-078-121D H07FOGM4VBL 75 20 ± 40
-078-130D S11FOGM4VBL 115 30 ± 40
-078-131D H11FOGM4VBL 115 30 ± 40
-078-140D S15FOGM4VBL 150 40 ± 40
S
07
09
95
12345678910
75
11
115
1
2
15
150
Valve version
Standard response
Rated flow
F
3
210
Maximum operating pressure in bar (psi)
(3,000)
For = 35 bar (500 psi) per spool land
p
Model number (assigned at the factory) Type designation
(25)
(20)
(30)
N
O
D
4
Bushing/spool design
4-way: 10 % overlap
4-way: axis cut, zero lap
4-way: 2 % underlap, no overlap
N
H
High response
8
V
Fluorocarbon (FKM)
7
4
6
M
5
9
B
G
10
L
M
Z
± 40 mA
± 50 mA
± 200 mA
Signals for 100 % spool stroke
(single or parallel coil value)
Seal material
4 pin MS threaded connector over B-side
Internal supply
Pilot connections
High dynamics
Pilot stage design
Spool position without electrical signal
Center position
Valve connector
A
4 pin MS threaded connector over A-side
2
4 lead pigtail connector over A-side
(40)
A
B
Port B open to return
Port A open to return
l/min (gpm)
Ascension number
Model revision
Standard
Intrinsically
Safe (I.S.)
Explosion
Proof (E.P.)
K
-
N
- 078
ORDERING CODE
ORDERING INFORMATION
Australia
+61 3 9561 6044
Service + 61 3 8545 2140
info.australia@moog.com
service.australia@moog.com
Brazil
+55 11 3572 0400
info.brazil@moog.com
service.brazil@moog.com
Canada
+1 716 652 2000
info.canada@moog.com
China
+86 21 2893 1600
Service +86 21 2893 1626
info.china@moog.com
service.china@moog.com
France
+33 1 4560 7000
Service +33 1 4560 7015
info.france@moog.com
service.france@moog.com
Germany
+49 7031 622 0
Service +49 7031 622 197
info.germany@moog.com
service.germany@moog.com
Hong Kong
+852 2 635 3200
info.hongkong@moog.com
India
+91 80 4057 6666
Service +91 80 4057 6604
info.india@moog.com
service.india@moog.com
Ireland
+353 21 451 9000
info.ireland@moog.com
Italy
+39 0332 421 111
Service 800 815 692
info.italy@moog.com
service.italy@moog.com
Japan
+81 46 355 3767
info.japan@moog.com
service.japan@moog.com
Korea
+82 31 764 6711
info.korea@moog.com
service.korea@moog.com
Luxembourg
+352 40 46 401
info.luxembourg@moog.com
The Netherlands
+31 252 462 000
info.thenetherlands@moog.com
service.netherlands@moog.com
Russia
+7 8 31 713 1811
Service +7 8 31 764 5540
info.russia@moog.com
service.russia@moog.com
Singapore
+65 677 36238
Service +65 651 37889
info.singapore@moog.com
service.singapore@moog.com
South Africa
+27 12 653 6768
info.southafrica@moog.com
Spain
+34 902 133 240
info.spain@moog.com
Sweden
+46 31 680 060
info.sweden@moog.com
Turkey
+90 216 663 6020
info.turkey@moog.com
United Kingdom
+44 (0) 1684 858000
Service +44 (0) 1684 278369
info.uk@moog.com
service.uk@moog.com
USA
+1 716 652 2000
info.usa@moog.com
service.usa@moog.com
For product information, visit www.moog.com/industrial
For service information, visit www.moogglobalsupport.com
Moog is a registered trademark of Moog Inc. and its subsidiaries.
All trademarks as indicated herein are the property of Moog Inc. and its subsidiaries.
©2021 Moog Inc. All rights reserved. All changes are reserved.
Catalog, Flow Control Servo Vales, 78 Series
STS/Rev. P, March 2024, CDL6272-en
WHAT MOVES YOUR WORLD
TAKE A CLOSER LOOK.
Moog designs a range of motion control products that complement the performance of those featured in this catalog.
Visit our website for more information and contact the Moog facility nearest you.
