Fisher Instruction Manual: Fisher 657NS Diaphragm Actuators Size 40, 45, 70, and 80 Manuals & Guides

Instruction Manual

D102602X012

657NS Actuator

June 2017

Fisher

™

657NS Diaphragm Actuators

Size 40, 45, 70, and 80

Contents

Introduction 1.................................

Scope of Manual 1.............................

Description 1.................................

Specifications 3...............................

Educational Services 3.........................

Installation 3..................................

Actuator Mounting 4..........................

Direct‐Acting

(Push‐Down‐to‐Close) Valves 4............

Reverse‐Acting

(Push‐Down‐to‐Open) Valves 5............

Loading Connection 6..........................

Adjustments 8.................................

Travel 8......................................

Spring 8.....................................

Bench Set 8...............................

Bench Set Adjustments 9...................

Operation 9...................................

Maintenance 10................................

Replacement of the Elastomeric Parts 11..........

Size 40, 45, and 70 Actuators 11.............

Size 80 Actuators 12.......................

Disassembly 12...............................

Size 40, 45, and 70 Actuators 12.............

Size 80 Actuators 12.......................

Assembly 13..................................

Size 40, 45, and 70 Actuators 13.............

Size 80 Actuators 14.......................

Parts Ordering 16...............................

Parts List 17...................................

Introduction

Scope of Manual

This manual provides installation, maintenance, and parts list information for the Fisher 657NS actuator. Refer to
separate instruction manuals for information regarding the control valve and accessories.

Do not install, operate, or maintain 657NS actuators 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
proceeding.

Description

The 657NS actuator is a direct‐acting, spring‐opposed diaphragm actuator used for operation of automatic control
valves. The 657NS actuator yoke construction and special yoke‐to‐bonnet bolting provides a high structural resonant
frequency that exceeds most nuclear service seismic requirements.

or Local Business Partner before

www.Fisher.com

657NS Actuator

June 2017

Table 1. Fisher 657NS Specifications

SPECIFICATION

2

Nominal Effective Area

Yoke Boss Diameters

Acceptable Valve Stem Diameters

Maximum Allowable Output Thrust

Maximum Travel

Maximum Casing Pressure for Actuator Sizing

Maximum Diaphragm Casing Pressure

Material Temperature Capabilities

1. Do not exceed maximum allowable valve stem load when applying maximum allowable thrust.

2. Maximum allowable diaphragm casing pressure may be used only when maximum allowable stem forces are not exceeded.

3. The pressure and temperature limitations in this manual, and any applicable code limitation, should not be exceeded.

(1)

(3)

(2, 3)

(3)

cm

2

Inch

mm 71 71 90 5H
Inch 2‐13/16 2‐13/16 3‐9/16 5H
mm 12.7 12.7 19.1 25.4 & 31.8
Inch 1/2 1/2 3/4 1 & 1‐1/4

N 12,015 23,352 42,720 88,110

Lb 2700 5250 9600 19,800
mm 38 51 76 76
Inch 1.5 2 3 3

Bar 4.5 3.4 3.8 4.9

Psig 65 50 55 70

Bar 5.2 4.1 4.5 5.5

Psig 75 60 65 80

40 45 70 80

445 677 1419 see table 3

69 105 220 see table 3

-40 to 82_C (-40 to 180_F) with nitrile diaphragm

Instruction Manual

D102602X012

ACTUATOR SIZE

Table 2. Diaphragm Casing Volumes, cm3 (Inch3)

ACTUATOR

SIZE

40 934 (57) 1475 (90) 1704 (104) 1852 (113) 2327 (142) 2786 (170) ‐ ‐ ‐ ‐ ‐ ‐

45 1556 (95) ‐ ‐ ‐ 2786 (170) 2999 (183) 3720 (227) 4424 (270) 5408 (330) ‐ ‐ ‐

70 3490 (213) 5244 (320) 5948 (363) 6424 (392) 7833 (478) 9242 (564) 11,110 (678) 14,879 (908)

80 4818 (294) ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ 10,488 (640) 12,454 (760) 14,863 (907) 19,337 (1180)

CLEARANCE

VOLUME, cm

(INCH3)

3

11 (0.4375) 16 (0.625) 19 (0.75) 29 (1.125) 38 (1.5) 51 (2) 76 (3)

TRAVEL, mm (INCH)

Table 3. Size 80 Diaphragm Area

TRAVEL TRAVEL AREA

mm Inch cm

0
19
29
38

51
64
76

0

0.75

1.125

1.5

2

2.5
3

2039
1903
1865
1845

1832
1800
1761

2

Inch

316
295
289
286

284
279
273

2

Table 4. Actuator Stem Assembly Bolt Torque Values

ACTUATOR SIZE

40
45
70
80

NSm LbfSFt

108
271
271
542

TORQUE

80
200
200
400

Table 5. Bonnet‐to‐Actuator Bolt Torque Values

ACTUATOR SIZE

40
45
70
80

2

BONNET‐ACTUATOR STUD BOLT TORQUE

NSm LbfSFt

102
102
176
292

75

75
130
215

Instruction Manual

D102602X012

657NS Actuator

June 2017

Specifications

Tables 1, 2, and 3 provide specifications for the various sizes of 657NS actuators discussed in this instruction manual.
Specific actuator information is found on the actuator yoke nameplate.

WARNING

To avoid personal injury or property damage, do not exceed pressure and temperature limits specified in table 1.

Educational Services

For information on available courses for the Fisher 657NS diaphragm actuator, as well as a variety of other products,
contact:

Emerson Automation Solutions
Educational Services - Registration
Phone: [phone] or 1-800-338-8158
E-mail: [e-mail]
emerson.com/fishervalvetraining

Installation

The diaphragm actuator is normally shipped mounted on a valve body. Follow the valve body instructions when
installing the control valve in the pipeline.

WARNING

Always wear protective gloves, clothing, and eyewear when performing any installation operations to avoid personal
injury.

Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.

If installing into an existing application, also refer to the WARNING at the beginning of the Maintenance section in this
instruction manual.

WARNING

If the control valve and actuator are installed with the actuator in any position other than vertical, the actuator may not
conform with safety‐related qualifications. Nonvertical orientation should be part of existing qualification analysis on file
at the plant site to ensure conformance with safety‐related qualifications.

3

657NS Actuator

June 2017

The control valve assembly normally may be installed in any orientation; however, the assembly must not be installed
so that water can collect in the actuator yoke and lower diaphragm casing areas.

Note

The 657NS actuator will not mount on a standard valve bonnet; it requires a style NS bonnet having eight bonnet‐to‐yoke stud
bolts.

If the actuator and control valve body are separate, mount the 657NS actuator on the valve body by following the
procedures in the Actuator Mounting section of this manual.

Instruction Manual

D102602X012

Actuator Mounting

Direct‐Acting (Push‐Down‐to‐Close) Valves

See figure 1.

1. Screw the stem locknuts all the way onto the valve stem. Put the travel indicator disk, not used with the size 80
actuator, on the stem locknuts. The concave side of the disk should face the valve.

2. Push the valve stem down to close the valve.

3. Lift or hoist the actuator onto the valve bonnet.

4. Insert the cap screws and tighten the hex nuts (not shown), securing the actuator to the bonnet. Tighten the cap
screws to the torque shown in table 5.

5. Thread the spring adjustor (see figure 1 for sizes 40 through 70 and key 12, figure 4 for size 80) until the actuator is
at the full up position.

6. With the travel indicator scale attached to the actuator yoke, make a temporary mark on the actuator stem at a
point parallel with the top mark on the travel indicator scale. This is the fully open position.

7. Refer to the actuator nameplate to determine the bench set pressure range of the actuator. Apply the lower bench
set pressure to the actuator, and turn the spring adjustor until the actuator stem mark is even with the top mark on
the travel indicator scale.

8. Apply the higher bench set pressure to the actuator. Verify that the mark on the actuator stem is even with the
bottom mark on the travel indicator scale. This is the fully closed position. The distance from the top mark on the
scale to the bottom mark is equal to the travel of the valve.

If the marks are in line, the actuator is properly bench set.

If the marks are not in line, the spring is not correct for the specified bench set. It is necessary to use a different spring

or a different bench set.

WARNING

To avoid personal injury due to the sudden uncontrolled movement of parts, do not loosen the cap screws when the stem
connector has spring or loading pressure force applied to it.

CAUTION

Incomplete engagement of the valve stem and/or actuator stem in the stem connector can result in stripped threads or
improper operation. Be sure that the length of each stem clamped in the stem connector is equal to or greater than the
diameter of that stem.

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Instruction Manual

D102602X012

Note

Replacement stem connectors are an assembly of two stem connector halves, cap screws, and a spacer between the connector
halves. Remove the spacer, if present, before clamping the stems together.

657NS Actuator

June 2017

9. Push the valve stem firmly against its seat, and be sure that it remains firmly against the seat. Clamp the actuator
stem and valve stem between the two stem connector halves. If necessary, increase loading pressure slightly to
allow the valve stem, actuator stem, and stem connector threads to match.

Insert and tighten the stem connector cap screws.

10. Raise the travel indicator disk to the stem connector (for sizes 40 through 70). For all sizes, thread the stem
locknuts against the stem connector.

11. Remove all loading pressure. Move the travel indicator scale so that the indicator disk (or pointer) is in line with the
top mark of the travel indicator scale.

12. Check the valve travel to be sure that the valve travels fully with no overtravel.

Reverse‐Acting (Push‐Down‐to‐Open) Valves

See figure 1.

1. Screw the stem locknuts all the way onto the valve stem. Put the travel indicator disk (not used with the size 80
actuator) on the stem locknuts. The concave side of the disk should face the valve.

2. Push the valve stem down to open the valve.

3. Lift or hoist the actuator onto the valve bonnet.

4. Insert the cap screws and tighten the hex nuts (not shown), securing the actuator to the bonnet. Tighten the cap
screws to the torque shown in table 5.

5. Apply actuator loading pressure until the actuator is at the full down position.

6. With the travel indicator scale attached to the actuator yoke, make a temporary mark on the actuator stem at a
point parallel with the bottom mark on the travel indicator scale. This is the fully open position.

7. Refer to the actuator nameplate to determine the bench set pressure range of the actuator. Apply the lower bench
set pressure to the actuator. Turn the spring adjustor until the actuator stem mark is even with the top mark on the
travel indicator scale.

8. Apply the higher bench set pressure to the actuator and verify that the mark on the actuator stem is even with the
bottom mark on the travel indicator scale. This is the fully‐open position. The distance from the top mark on the
scale to the bottom mark is equal to the travel of the valve.

If the marks are in line, the actuator is properly bench set.

If the marks are not in line, the spring is not correct for the specified bench set. It is necessary to use a different spring

or a different bench set.

WARNING

To avoid personal injury due to the sudden uncontrolled movement of parts, do not loosen the cap screws when the stem
connector has spring or loading pressure force applied to it.

5

657NS Actuator

June 2017

Instruction Manual

D102602X012

CAUTION

Incomplete engagement of the valve stem and/or actuator stem in the stem connector can result in stripped threads or
improper operation. Be sure that the length of each stem clamped in the stem connector is equal to or greater than the
diameter of that stem.

Note

Replacement stem connectors are an assembly of two stem connector halves, cap screws, and a spacer between the connector
halves. Remove the spacer, if present, before clamping the stems together.

9. Reduce loading pressure until the temporary mark on the actuator stem is parallel with the top mark on the
indicator scale.

10. Pull the valve stem firmly against its seat, and be sure that it remains firmly against the seat. Clamp the actuator
stem and valve stem between the two stem connector halves. If necessary, increase loading pressure slightly to
allow the valve stem, actuator stem, and stem connector threads to match.

Insert and tighten the stem connector cap screws.

11. Raise the travel indicator disk to the stem connector (sizes 40 through 70 only). For all sizes, thread the stem
locknuts against the stem connector.

12. Remove all loading pressure. Move the travel indicator scale so that the indicator disk (or pointer) is in line with the
top mark of the travel indicator scale.

13. Check the valve travel to be sure that the valve travels fully with no overtravel.

Loading Connection

1. Connect the loading pressure piping to the NPT internal connection in the top of the actuator yoke.

2. For size 70 actuators, remove the 1/4‐inch bushing in the 1/2 NPT internal connection to increase connection size, if
necessary. The connection can be made with either piping or tubing.

3. Keep the length of tubing or piping as short as possible to avoid transmission lag in the control signal. If a volume
booster, valve positioner or other accessory is used, be sure that it is properly connected to the actuator. Refer to
the positioner instruction manual as necessary.

4. Cycle the actuator several times to check that the valve stem travel is correct and that the travel occurs when the
correct pressure range is applied to the diaphragm.

5. If valve stem travel is incorrect, refer to the Travel procedure in the Adjustments section.

6. If the pressure range is incorrect, refer to the Spring procedure in the Adjustments section.

6