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Fisher
r
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 Process Management sales office before
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.
Instruction Manual
D102602X012
657NS Actuator
November 2012
