Emerson Fisher 656 User manual

www.Fisher.com
Fisher™656 Diaphragm Actuator
Contents
Introduction 1.................................
Scope of Manual 1.............................
Description 1.................................
Principle of Operation 2.........................
Specifications 2...............................
Maximum Pressure Limitations 3................
Installation 3..................................
Adjustment 3..................................
Maintenance 4.................................
Disassembly 4................................
Assembly 5...................................
Parts Ordering 7................................
Parts List 7....................................
Handwheel Assembly 7........................
Casing‐Mounted Adjustable Down
Travel Stop 11..............................
Figure 1. Fisher 656 Actuator
W0454
Introduction
Scope of Manual
This instruction manual includes installation, maintenance, and parts information for Fisher 656 diaphragm actuators.
Refer to separate manuals for instructions covering the valve, positioner, and accessories.
Description
Fisher 656 actuators are long stroke, spring opposed, direct‐acting diaphragm actuators. They operate Vee‐Ballt
control valves, butterfly valves, built‐in turbine valves, louvers, dampers and similar equipment. They are suitable for
either push‐down‐to‐close (PDTC) or push‐down‐to‐open (PDTO) applications and are available in sizes 30, 40 and 60
to provide 54 mm (2.125 inch), 64 mm (3.5 inch) and 105 mm (4.125 inch) travel, respectively.
Do not install, operate, or maintain a 656 actuator without being fully trained and qualified in valve, actuator, and
accessory installation, operation, and maintenance. To avoid personal injury or property damage, it is important to
carefully read, understand, and follow all the contents of this manual, including all safety cautions and warnings. If you
have any questions about these instructions, contact your Emerson sales office or Local Business Partner before
proceeding.
Instruction Manual
D100304X012
656 Actuator
June 2017

Instruction Manual
D100304X012
656 Actuator
June 2017
2
Table 1. Specifications
Maximum Recommended Casing Operating
Pressure(1)
2.4 bar (35 psig)
Maximum Allowable Casing Pressure(2)
Actuator
Size
Maximum
Casing
Pressure for
Actuator
Sizing(2),
Bar (Psig)
Maximum
Excess
Diaphragm
Pressure(1),
Bar (Psig)
Maximum
Diaphragm
Casing
Pressure(2,3),
Bar (Psig)
30 8.6 (125) 1.0 (15) 9.7 (140)
40 4.5 (65) 0.69 (10) 5.2 (75)
60 2.8 (40) 0.69 (10) 3.4 (50)
1. Additional pressure may be added when the actuator is at full travel. If the Maxi
mum Excess Diaphragm Pressure is exceeded, damage to the diaphragm or dia
phragm casing might result. See the Maximum Pressure Limitation section.
2. Maximum diaphragm casing pressure must not be exceeded and must not produce
a force on the actuator stem greater than the maximum allowable actuator output
thrust or the maximum allowable stem load. See the Maximum Pressure Limitation
section.
3. This maximum casing pressure is not to be used for normal operating pressure. Its
purpose is to allow for typical regulator supply settings and/or relief valve tolerances.
Operating Temperature Range(3)
J-40 to 82°C (-40 to 180°F) with Nitrile Elastomer
J-40 to 149°C (-40 to 300°F) with Silicone
Diaphragm
Casing Pressure Connection
1/4 NPT internal
Maximum Travel
ACTUATOR SIZE
MAXIMUM RATED
STEM TRAVEL,
mm (INCHES)
Standard
Travel
Stop
Optional
Travel
Stop
30 54 (2.125) Not available
40 89 (3.5) 76 (3)
60 105 (4.125) 97 (3.8125)
Actuator Weight
Actuator Size
Approximate
Shipping Weight,
kg (Pounds)
30 23 (50)
40 32 (70)
60 73 (160)
Options
JTop‐mounted handwheel/adjustable travel stop
JCasing‐mounted adjustable down travel stop
1. Control and stability may be impaired if this pressure is exceeded.
2. Exceeding this pressure can cause damage to the diaphragm, diaphragm casing, or other parts.
3. The temperature limits in this manual and any applicable standard or code limitation for valve should not be exceeded.
Principle of Operation
In a direct acting diaphragm actuator, increasing loading pressure moves the actuator stem downward, compressing
the spring. When the diaphragm pressure is decreased, the spring moves the actuator stem upward. In the event of
failure of the loading pressure, the actuator stem moves to the extreme upward position.
Specifications
Refer to table 1 for Specifications of the 656 actuator. See the actuator nameplate for specific information for your
actuator.
WARNING
To avoid personal injury or damage to equipment that may result in the malfunction of the control valve or loss of control
of the process caused by excessive pressure, do not exceed the Maximum Pressures listed in table 1. Refer to the following
Maximum Pressure Limitations section.

Instruction Manual
D100304X012
656 Actuator
June 2017
3
Maximum Pressure Limitations
The casing and diaphragm of 656 actuators are pressure operated. This air pressure provides energy to compress the
spring, to stroke the actuator, and to seat the valve. The following explanations describe the maximum pressure limits
for an actuator. Refer to the nameplate or table 1 for maximum values for your actuator.
D Maximum Casing Pressure for Actuator Sizing: This is the maximum pressure that can be applied at less than full
travel of the actuator. If this stroking pressure is exceeded before the upper diaphragm plate contacts the travel
stop, damage to the stem or other parts might result.
D Maximum Excess Diaphragm Pressure: Additional pressure may be added when the actuator is at full travel. If the
Maximum Excess Diaphragm Pressure is exceeded, damage to the diaphragm or diaphragm casing might result.
Because the actuator has traveled its specified travel, and the diaphragm head is physically stopped from movement,
the energy from any additional air pressure is transmitted to the diaphragm and diaphragm casings. The amount of air
pressure that can be added once the actuator has traveled to the stops is limited by the resultant adverse effects that
may occur. Exceeding this limiting factor could result in leakage or casing fatigue due to the deformation of the upper
diaphragm casing.
D Maximum Diaphragm Casing Pressure: If the Maximum Diaphragm Casing Pressure is exceeded, damage to the
diaphragm, diaphragm casing, or actuator might result.
Installation
When an actuator and valve are shipped together, the actuator is normally mounted on the valve. Follow the valve
instructions when installing the valve and actuator in a pipeline. If the actuator is shipped separately, or if it is
necessary to mount the actuator on the valve, four holes have been tapped into the yoke boss to anchor it to a
mounting bracket.
WARNING
Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal
injury.
To avoid personal injury or property damage caused by bursting of pressure retaining parts, be certain the diaphragm
casing pressure does not exceed the limits listed in the Specifications table. Use pressure relieving or pressure limiting
devices to prevent the diaphragm casing pressure from exceeding these limits.
If installing into an existing application, also refer to the WARNING at the beginning of the Maintenance section in this
instruction manual.
To make the stem connection, follow the appropriate assembly step 10 in the Maintenance section. Standard actuator
sizes 30 and 40 have mounting holes tapped 3/8 inch UNC, and the size 60 mounting holes are tapped 1/2 inch UNC.
A 1/4 NPT loading pressure connection is located in the top of the upper diaphragm case. Using either pipe or tubing,
connect either the loading pressure connection or valve positioner input connection (if a valve positioner is furnished,
the loading pressure connection to the actuator will be made at the factory) to the output pressure connection on the
controller. Keep the length of the pipe or tubing as short as possible to avoid transmission lag in the control signal.
Adjustment
When the actuator is completely installed and connected to the controller, it should be checked for correct travel,
freedom from friction and correct PDTC or PDTO action.

Instruction Manual
D100304X012
656 Actuator
June 2017
4
The actuator spring and diaphragm have been selected to meet the requirements of the application. It should be
noted that the actuator spring has a constant rate of compression and that adjustment of the spring compression
merely shifts the initial spring setpoint up or down to make the actuator travel within the initial spring setpoint and the
maximum diaphragm pressure indicated on the nameplate.
In some instances, however, such as high friction butterfly and ball valves, the actuator will fully stroke with less
diaphragm pressure than indicated on the nameplate. To increase the pressure required to initiate actuator stem
movement, turn the lower bearing seat (key 14) up toward the spring case. To decrease the pressure at which
movement begins, turn the lower bearing seat down, away from the spring case.
Maintenance
WARNING
Avoid personal injury or property damage from sudden release of process pressure or uncontrolled movement of parts.
Before performing any maintenance operations:
D Do not remove the actuator from the valve while the valve is still pressurized.
D Always wear protective gloves, clothing, and eyewear when performing any maintenance operations to avoid personal
injury.
D Disconnect any operating lines providing air pressure, electric power, or a control signal to the actuator. Be sure the
actuator cannot suddenly open or close the valve.
D Use bypass valves or completely shut off the process to isolate the valve from process pressure. Relieve process pressure
from both sides of the valve. Drain the process media from both sides of the valve.
D Vent the power actuator loading pressure and relieve any actuatorspring precompression.
D Use lock‐out procedures to be sure that the above measures stay in effect while you are working on the equipment.
D The valve packing box may contain process fluids that are pressurized, even when the valve has been removed from the
pipeline. Process fluids may spray out under pressure when removing the packing hardware or packing rings, or when
loosening the packing box pipe plug.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
Disassembly
1. If the actuator is installed on a control valve, isolate or bypass the control valve.
2. Shut off the diaphragm loading pressure and remove the pipe or tubing from the loading pressure connection in
the top of the diaphragm case.
3. Turn the lower bearing seat (key 14) down, away from the spring case to relieve all spring compression.
4. If the entire actuator is to be removed from its mounting, disconnect the actuator stem (key 10) from the stem
connector, clevis, etc., and remove the jam nuts (key 23). Loosen the cap screws that hold the yoke (key 9) to its
mounting plate or bracket, and lift the entire actuator from its mounting.
5. Remove the diaphragm case cap screws and nuts (keys 19 and 20) and lift the upper diaphragm case (key 1 ) off the
actuator. Remove the diaphragm (key 2).
6. Lift out the diaphragm plate (key 4) and stem (key 10). They may be separated by removing the cap screw (key 3).

Instruction Manual
D100304X012
656 Actuator
June 2017
5
Figure 2. Travel Stop Orientation for Size 60
11A0001‐A
A
A
A
MOUNTING BOSS
ON ACTUATOR YOKE
LOCATE FOUR TRAVEL
STOPS MARKED A
MOUNTING BOX
ON ACTUATOR YOKE
7. Take out the actuator spring (key 6).
8. The lower diaphragm case (key 5) can be removed from the yoke, if required, by loosening the travel stops and cap
screws (keys 7 and 8).
9. Remove the lower spring seat (key 11) and thrust bearing (key 13). Unscrew the lower bearing seat (key 14) from
the adjusting screw (key 12).
10. Remove the set screw (key 22) and remove the adjusting screw to complete disassembly.
Assembly
1. Apply lithium grease lubricant, or equivalent, to the adjusting screw threads (key 12) and screw this into the yoke
(key 9). Replace set screw (key 22). The set screw should engage the machined thread relief in the adjusting screw.
2. With the eared portion up, screw the lower bearing seat (key 14) all the way onto the adjusting screw.
3. Apply lithium grease lubricant, or equivalent, to the thrust bearing (key 13) and position it on the lower bearing seat
(key 14). Lay the lower spring seat (key 11) on top of the thrust bearing assembly.
4. Mount the lower diaphragm case (key 5) to the top of the yoke (key 9) using the travel stops and cap screws (keys 7
and 8). Alternate screws and travel stops on the sizes 30 and 40. See figure 2 for the correct orientation of the size
60.
5. Position the actuator spring (key 6) on the lower spring seat.
6. Attach the diaphragm plate (key 4) to the actuator stem (key 10) with the cap screw (key 3). Apply lithium grease
lubricant, or equivalent, to the stem. Place this assembly, actuator stem first, into the yoke with the actuator stem
through the spring adjustor (key 12).
7. Position the diaphragm (key 2) on the diaphragm plate (key 4) and align the holes with the lower diaphragm casing
(key 5). Attach the upper diaphragm case (key 1) to the lower diaphragm casing (key 5) using the cap screws and
nuts
(keys 19 and 20).
Note
When you replace actuator diaphragms in the field, take care to ensure the diaphragm casing bolts are tightened to the proper
load to prevent leakage, but not crush the material.

Instruction Manual
D100304X012
656 Actuator
June 2017
6
Note
Do not use lubricant on these bolts and nuts. Fasteners must be clean and dry.
a. The first four bolts tightened should be diametrically opposed and 90 degrees apart. Tighten these four bolts to
13 NSm (10 lbfSft).
b. Tighten the remaining bolts in a clockwise, criss‐cross pattern to 13 NSm (10 lbfSft).
c. Repeat this procedure by tightening four bolts, diametrically opposed and 90 degrees apart, to a torque of 27
NSm (20 lbfSft).
d. Tighten the remaining bolts in a clockwise, criss‐cross pattern to 27 NSm (20 lbfSft).
e. After the last bolt is tightened to 27 NSm (20 lbfSft), all of the bolts should be tightened again to 27 NSm (20
lbfSft) in a circular pattern around the bolt circle. Once completed, no more tightening is recommended.
8. If the actuator has been removed from its mounting, position it on its mounting plate or bracket, and secure with
cap screws.
9. Attach the pressure pipe or tubing to the loading pressure connection on top of the upper diaphragm case.
10. Attach the actuator stem to the stem connector or clevis and adjust the travel by using the appropriate procedure
below.
D For Push‐Down‐to‐Open applications:
1. Set the controlled element (valve plug, louver, damper, etc.) in the closed position.
2. Turn the lower bearing seat (key 14) up toward the spring case far enough to ensure that the actuator stem is at the
top of its stroke.
3. Make the actuator stem connection, making sure that there is full engagement of the actuator stem threads.
Tighten slightly.
4. Apply loading pressure to the diaphragm case to move the controlled element toward its wide open position. Screw
the controlled element linkage into the actuator stem connection far enough to move the controlled element
toward its closed position 3.2 mm (1/8 inch), and tighten the stem connection securely. This adjustment ensures
that the controlled element will close before the actuator stem travels to the top of its stroke. The travel stops (key
7) in the lower diaphragm case ensure correct travel of the controlled element in the open direction.
5. If travel starts at a lower or higher pressure than is required for proper operation, turn the lower bearing seat (key
14) up or down respectively, as described in the Adjustment section.
D For Push‐Down‐to‐Close applications:
1. Set the controlled element (valve plug, louver, damper, etc.) in the open position.
2. Turn the lower bearing seat (key 14) up toward the spring case far enough to ensure that the actuator stem is at the
top of its stroke.
3. Tighten the actuator stem connection slightly, making sure that there is full engagement of the actuator stem
threads.
4. Apply loading pressure to the diaphragm case and observe the travel of the controlled element to make sure that it
closes completely. If the travel is not correct, it can be changed by screwing the controlled element linkage in or out
of the stem connection. When the travel is set correctly, tighten the stem connection securely, and lock the jam
nuts (key 23).
5. If travel starts at a lower or higher pressure than is required for proper operation, turn the lower bearing seat in or
out respectively, as described in the Adjustment section.

Instruction Manual
D100304X012
656 Actuator
June 2017
7
Parts Ordering
When corresponding with your Emerson sales office or Local Business Partner about this equipment, refer to the serial
number found on the actuator nameplate.
WARNING
Use only genuine Fisher replacement parts. Components that are not supplied by Emerson Automation Solutions should
not, under any circumstances, be used in any Fisher valve, because they may void your warranty, might adversely affect the
performance of the valve, and could cause personal injury and property damage.
Parts List
Note
Contact your Emerson sales office or Local Business Partner for Part
Ordering information.
Key Description
1 Diaphragm Case, steel
Standard
2* Diaphragm, Nitrile
Size 30
Size 40
Size 60
3 Cap Screw, steel
4 Diaphragm Plate, cast iron
5 Lower Diaphragm Case, steel
6 Actuator Spring, steel
7 Down Travel Stop, steel Sizes 30 & 40 (3 req'd),
Size 60 (4 req'd)
8 Cap Screw, steel Sizes 30 & 40 (3 req'd), Size 60 (4 req'd)
9 Yoke, cast iron
10 Actuator Stem, steel
11 Lower Spring Seat, steel
12 Adjusting Screw, brass
13 Thrust Bearing, steel ball bearing
14 Lower Bearing Seat, steel
Key Description
17 Nameplate, SST
18 Drive Screw, SST (6 req'd)
19 Cap Screw, steel Size 30 (12 req'd), Size 40 (16 req'd),
Size 60 (24 req'd)
20 Hex Nut, steel Size 30 (12 req'd), Size 40 (16 req'd),
Size 60 (24 req'd)
21 Valve Stem, 316 SST (Size 30 only)
22 Set Screw, steel
23 Hex Nut, steel (2 req'd)
25 Warning Nameplate
Handwheel Assembly
51 Handwheel, cast iron
54 Jam Nut, steel
133 Stem, brass
135 Pusher Plate Assembly, steel
137 Jam Nut, steel
138* O‐ring, nitrile
Size 30 & 40
Size 60
139* O‐ring, nitrile
Size 30 & 40
Size 60
140 Groove Pin, steel
141 Cap Screw, steel Sizes 30 & 40 (6 req'd), Size 60 (8 req'd)
142 Handwheel body, cast iron
164 Body Extension, steel
171 Spacer, 416 SST (size 60 only)
*Recommended spare parts

Instruction Manual
D100304X012
656 Actuator
June 2017
8
Figure 3. Fisher 656 Size 30 Actuator
A
APPLY THREAD LOCKING ADHESIVE (HIGH STRENGTH) TO SURFACE A
CK1580
A0345‐1
Figure 4. Fisher 656 Size 40 & 60 Actuators
40A7798A
APPLY LITHIUM GREASE LUBRICANT ON SURFACES A & B
A
B

Instruction Manual
D100304X012
656 Actuator
June 2017
9
Figure 5. Typical Top‐Mounted Handwheel Assembly for Diaphragm Actuator, Size 30 & 40
LUBRICATE END OF STEM AND PLATE WITH LITHIUM GREASE
LUBRICATE STEM THREADS WITH ANTI‐SEIZE LUBRICANT
38A1209‐D

Instruction Manual
D100304X012
656 Actuator
June 2017
10
Figure 6. Typical Top‐Mounted Handwheel Assembly for Diaphragm Actuator, Size 60
LUBRICATE END OF STEM AND PLATE WITH LITHIUM GREASE
LUBRICATE STEM THREADS WITH ANTI‐SEIZE LUBRICANT
32B0262‐B

Instruction Manual
D100304X012
656 Actuator
June 2017
11
Figure 7. Casing‐Mounted Adjustable Down Travel Stop for Size 30 and 40 Actuators (Style 2)
APPLY LUB
BV8054-D
Casing‐Mounted Adjustable
Down Travel Stop (figure 7)
Key Description
54 Stop Nut
133 Travel Stop Stem
134 Washer
Key Description
139* O‐Ring, nitrile
Sizes 30, 34, & 40
Sizes 45, 46, 50, & 60
Sizes 70 & 87
141 Cap Screw
142 Body
187 Travel Stop Cap
189 Jam Nut
241 Lubricant, Lithium Grease or equivalent
(not furnished with travel stop)
*Recommended spare parts

Instruction Manual
D100304X012
656 Actuator
June 2017
12
www.Fisher.com
The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not
to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. All sales are
governed by our terms and conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications of such
products at any time without notice.
E1974, 2017 Fisher Controls International LLC. All rights reserved.
Fisher and Vee-Ball are marks owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson
Automation Solutions, Emerson, and the Emerson logo are trademarks and service marks of Emerson Electric Co. All other marks are the property of their
respective owners.
Neither Emerson, Emerson Automation Solutions, nor any of their affiliated entities assumes responsibility for the selection, use or maintenance
of any product. Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.
Emerson Automation Solutions
Marshalltown, Iowa 50158 USA
Sorocaba, 18087 Brazil
Cernay, 68700 France
Dubai, United Arab Emirates
Singapore 128461 Singapore