72 Series

Servovalves

72 Series
Servovalves
72 SERIES
TWO STAGE SERVOVALVES

72 SERIES SERVOVALVES cantilever spring.The valve deflection of armature/flapper assembly. Once the restoring
design is simple and rugged for assembly within the flexure torque becomes equal to the
The 72 Series flow control dependable, long life operation. tube. Deflection of the flapper torque from the magnetic
servovalves are throttle valves restricts fluid flow through one forces, the armature/flapper
for 3 and preferably 4-way These valves are suitable for nozzle which is carried through assembly moves back to the
applications.They are a high electrohydraulic position, to one spool end, displacing neutral position, and the spool
performance, two-stage design speed, pressure or force con- the spool. is held open in a state of equi-
that covers the range of rated trol systems with high dynamic librium until the command sig-
flows from 25 to 60 gpm at response requirements. Movement of the spool opens nal changes to a new level.
1000 psi valve drop.The output the supply pressure port (P) to
stage is a closed center, four- Principle of operation one control port, while simul- In summary, the spool position
way sliding spool.The pilot An electrical command signal taneously opening the tank is proportional to the input
stage is a symmetrical double- (flow rate set point) is applied port (T) to the other control current and with constant
nozzel and flapper, driven by to the torque motor coils, and port.The spool motion also pressure drop across the valve,
a double air gap, dry torque creates a magnetic force which applies a force to the cantilever flow to the load is proportional
motor. Mechanical feedback of acts on the ends of the pilot spring, creating a restoring to the spool position.
spool position is provided by a stage armature.This causes a torque on the armature/flapper

VALVE FEATURES
➣ 2-stage design with dry torque motor ➣ Rugged, long-life design

➣ Low friction double nozzle pilot stage ➣ High resolution, low hysteresis

➣ High spool control forces ➣ Completely set-up at the factory

➣ High dynamics ➣ Optional fifth port for separate pilot supply

➣ Field replaceable pilot stage filter

The actual flow is dependent ∆p

upon electrical command signal Q = QN
∆pN
and valve pressure drop.The
flow for a given valve pressure
drop can be calculated using Q [gpm] = calculated flow
the square root function for QN [gpm] = rated flow
sharp edge orifices: ∆p [psi] = actual valve
pressure drop
∆pN [psi] = rated valve
pressure drop

This catalog is for users with technical to check the suitability of the
knowledge.To ensure that all necessary products described here. In case
characteristics for function and safety of doubt, please contact Moog Inc.
of the system are given, the user has

2
72 SERIES
GENERAL TECHNICAL DATA

Operating Pressure
ports P, X,A and B up to 3,000 psi* 1000
port T up to 3,000 psi
Temperature Range
Fluid -40°F to 275°F
Ambient -40°F to 275°F
Seal Material Viton **
Operating Fluid Compatible with common
hydraulic fluids, other fluids
on request.
100
Recommended viscosity 60-450 SUS @ 100°F 60
System Filtration: High pressure filter (without bypass,
but with dirt alarm) mounted in the main flow and if possible, 40
directly upstream of the valve. 25
Class of Cleanliness: The cleanliness of the hydraulic fluid
greatly effects the performance (spool positioning, high resolution)
and wear (metering edges, pressure gain, leakage) of the servovalve.
Recommended Cleanliness Class
10
For normal operation ISO 4406 < 14/11
For longer life ISO 4406 < 13/10
Filter Rating recommended
For normal operation ß10 ≥ 75 (10 µm absolute)
For longer life ß5 ≥ 75 (5 µm absolute)
Installation Operations Any position, fixed or moveable.
Vibration 30 g, 3 axes
Weight 7.75 lb. (3.52 kg)
1
Shipping Plate Delivered with an oil sealed 100 1000 10000
shipping plate.

* Maximum special order is 5,000 psi Valve Flow Diagram

** Other seal material upon request Valve flow for maximum valve opening (100% command
signal) as a function of the valve pressure drop.

P B T A

3
72 SERIES
TECHNICAL DATA

Model . . .Type 72 . . . . .
Mounting Pattern ISO 10372 - 06 - 05 - 0 -92
Valve Body Version 4-way
2-stage with spool-bushing assembly
Pilot Stage Nozzle/Flapper, High flow
Pilot Connection Optional Internal or External
Rated Flow (± 10%) at ∆pN = 1,000 psi [gpm] 25 40 60
Response Time* [ms] 16 26 40
Threshold* [%] < 1.5%
Hysteresis* [%] < 4.0%
Null Shift at ∆T = 100°F [%] < 4.0%
Null Leakage Flow* max. [gpm] 0.55 to 1.30
* Measured at 1,000 psi pilot or operating pressure

Step Response
100

4 6
2
80 Ps = 1000 PSI (70 bar)
1 1= 72-101
5 3
2 = 72-102
60
Stroke (% of max)

3 = 72-103
Ps = 3000 PSI (210bar)
40 4 = 72-101
5 = 72-102
6 = 72-103
20

0 10 20 30 40

Time (ms)

Typical characteristic
curves with ±40% and ±100%
input signal, measured at 3,000
pilot or operating pressure.

Standard Valves +2 +2 +2
Amplitude Ratio (dB)

Amplitude Ratio (dB)

Amplitude Ratio (dB)

0 0 0

-2 -2 -2

-4 -4 -4
3000 psi DTE-24
-6 -6 -6 at 100˚F (38˚C)
3000 psi DTE-24 3000 psi DTE-24 Rated Current:
-8
at 100˚F (38˚C)
-8
at 100˚F (38˚C)
-8 ±40%
100 100 100
Rated Current: Rated Current: ±100%
±40% ±40%
Phase Lag (degrees)

Phase Lag (degrees)

Phase Lag (degrees)

-10 ±100% 80 -10 ±100% 80 -10 80

60 60 60

40 40 40

20 20 20

0 0 0
7 10 15 20 30 50 70 100 150 200 7 10 15 20 30 50 70 100 150 200 7 10 15 20 30 50 70 100 150 200

Frequency (Hz) Frequency (Hz) Frequency (Hz)

Frequency Response Frequency Response Frequency Response
of 25 gpm Servovalves of 40 gpm Servovalves of 60 gpm Servovalves

4
72 SERIES
INSTALLATION DRAWINGS

3.62 MAX
[92.0]
1.81
[46.0] 2.875
[73.03]
4 MOUNTING HOLES 1.437
.406 [10.31] THRU [36.50]

1.687 2.03
[42.85] [51.6] 4.06
[103.1]
3.375
[85.73]
3.05
[77.5]

FIELD REPLACEABLE
FIRST STAGE FILTER .86 2.26
[22.0] 1.73 [57.4]
[43.9]

PIN D PIN A
5.15
OPTIONAL [130.8]
PIN C PIN B MAGNETIC 2.24
NULL ADJUST [56.9]
MECHANICAL
NULL ADJUST

1.37 3.28
2.75 [83.3] 4.48 2.38 [60.5]
[69.9] [34.8]
[113.8] 3.69 DIA TYP
1.50 MAX [93.7]
[38.1]
P

LOCATING PIN .28 6.70

.25 [6.4] [7.1] [170.2]

TYPICAL SUBPLATE MANIFOLD Null Adjust: Flow out of Control

Port B will increase with clockwise
rotation of null adjust screw
4X .375-16 UNC-2B THD
4.250 (3/32 hex key).
2.125 RETURN PORT T
.013 M
4X .406 THRU
.609 .60 2.000
.014 M 1.000
The mounting manifold
CONTROL PORT A
must conform to
ISO 10372-06-05-0-92.
2.125
1.687 Surface to which valve is
mounted requires a √ [∆∆]
32
(42.9)
5.00 1.000
3.375
2.000 .750
(85.7) finish, flat within 0.002[0.05] TIR.
4.250 1.500
1.500
2.50
Standard electrical connector
.39 .30 mates with MS3106F14S-2S
2

.014 M

CONTROL PORT B .750

or equivalent.
1.437 VALVE MOUNTS
1.60 4X .688 ON THIS MANIFOLD
(36.5)
.014 M SURFACE
2.875
.250 AUXILIARY PILOT (73) PRESSURE PORT P
PORT PER SAE J1926
.4375-20 UNF-2B PRESSURE PORT X
DASH 4 STR THD O-RING .014 M 2.50 32
BOSS (.25 TUBE OD REF) .002

4X PORT PER SAE J1926 1.25

1.625-12 UN-2B 4 PL
DASH 20 STR THD O-RING
2.50
BOSS (1.25 TUBE OD REF)
P

5.00

5
72 SERIES
ELECTRICAL CONNECTIONS

Rated current and Coil connections connections can be made for Servoamplifier
coil resistance A four-pin electrical series, parallel or differential The servovalve responds
A variety of coils are available connector (that mates operation. to input current, therefore
for 72 Series Servovalves, with an MS3106F14S-2S) 72 Series Servovalves a servoamplifier that has
which offer a wide choice of is standard. All four torque can be supplied on special high internal impedance
rated current. See Table I. motor leads are available order with other connectors. (as obtained with current
at the connector so external feedback) should be used.
This will reduce the effects
TABLE 1
of coil inductance and will
Nominal Recommended Rated Current–mA Approximate Coil Inductance*–Henrys minimize changes due to
Resistance coil resistance variations.
Parallel,
Per Coil at Differential or Single Series Coils Single Coils Series Coils Parallel Coils
77ºF (25ºC) Ω Coil Operation

80 ±40 ±20 0.22 0.66 0.18

200 ±15 ±7.5 0.72 2.20 0.59

1000 ±8 ±4 3.20 9.70 2.60

* Measured at 50 Hz

ELECTRICAL Parallel Series Single

CONNECTIONS
(Examples with typical 72 series coils) A B C D A B C D
A B C D

Coil Resistance [Ω] 100 400 200

Rated Current [mA] ±15 ±7.5 ±15
Electrical Power [W] .023 .023 .045
Connections for Valve Opening A and C (+) A (+), D (-) A (+), B (-)
P ➧ B, A ➧ T B and D (-) B and C connected or C (+), D (-)

Note: Before applying electrical signals, the pilot stage has to be pressurized.

External

Procedure to Configure a 72 Series Servovalve for External Pilot Operation

1. Remove the set screw from the “X” port on the base of the valve using a 1/8'' Allen wrench.

2.Thread a #2-56 screw into the o-ring plug that is now visible and remove it from the “X” port.

3. Remove the four (4) socket head cap screws and lockwashers that retain the cover plate for the
field replaceable filter, using a 5/32'' Allen wrench.

4. Use one of the screws to pull the filter and filter housing out of the filter cavity of the body. PRESSURE PORT
The filter housing has two (2) o-rings on its O.D.The housing will come part way out, then stop
after the second o-ring passes the internal relief in the body.At this time it may be easier to remove
the visible o-ring and carefully pry the housing and filter out with two opposing flat blade screw
drivers, than to continue pulling on the screw. Be careful not to damage the o-ring groove. Internal
5.A bore will be visible inside the body cavity where the o-ring plug must be inserted.

6. Retain the o-ring plug with the set screw.

7. Re-install the filter and filter housing in the cavity.

8. Re-install the filter cover, retaining screws and lockwashers.Torque the screws to 85 in-lbs.

X PORT

6
72 SERIES
ORDERING INFORMATION
SPARE PARTS AND ACCESSORIES

Model Number Type Designation

72 • • • • • • • • • • • • • • • • •

Optional Feature Signals for 100% Spool Stroke

Series specification 4 ±4 mA series (±8 mA parallel)
K Intrinsically safe H ±7.5 mA series (±15 mA parallel)
L ±20 mA series (±40 mA parallel)
Model Designation Y Special signal (see spec sheet)*
Assigned at the factory
Valve Connector
Factory Identification (Revision Level) A Connector over Port A – side (RH)
B Connector over Port B – side (LH)
Value Version X Special connector*
S Standard response

Seal Material
Rated Flow
V Viton
QN[gpm] at ∆pN = 1,000 psi
N NBR (Buna)
09 25
Others on request*
15 40
22 60
Pilot Connection
Maximum Operating Pressure Pp and Body Material 4 Internal
F 3,000 psi aluminum 5 External
K 5,000 psi steel body
Spool Position without Electrical Signal
Main Spool Type
M Mid position
O 4-way / axis cut / linear
A 4-way / < =3% overlap - critical lap / linear
D 4-way / +/-10% overlap / linear Pilot Stage
M 4-way / axis cut pc > 80% of pp / linear F Standard Dynamics
X Special*

Preferred configurations highlighted.

All combinations may not be available.
Options may increase price and delivery.
Technical changes are reserved.

* Optional designs are available with intrinsically safe coils (FM approved),
and/or special spool bushing lap configuration.Available seal materials:
VITON (Std.), BUNA or EPR.

SPARE PARTS AND ACCESSORIES

O-Rings (included in delivery), FPM 85 Shore Moog P/N
for P,T, A and B ID 0.801 x 0.070 42082-040
for X ID 0.364 x 0.070 42082-013
Mating Connector, waterproof IP 65 (not included in delivery) 49054F14S2S (MS3106F14S-2S)
Flushing Block G4321AM1
Mounting Bolts (not included in delivery)
3/8 - 16 NC x 2 long (4 pieces) A31324-332B
Replaceable Filter Cartridge 22050K2
Field Replaceable Filter Kit B52555RK99K1

7
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Industrial Controls Division

Moog Inc., East Aurora, NY 14052-0018
Telephone: 716/655-3000
Fax: 716/655-1803
Toll Free: 1-800-272-MOOG
www.moog.com

CDL6266 Rev K 500-226 502