Fisher 685SE Instructions Manual

Instruction Manual
D103799X012
™
Fisher 685SE and 685SR Piston Actuator
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scope of Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Three-Way Valve Applications Note
Actuator Mounting . . . . . . . . . . . . . . . . . . . . . . . . . .
Handwheel Operation . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Actuator Removal . . . . . . . . . . . . . . . . . . . . . . . . . .
685SE Seal and O-ring Replacement
685SR Seal and O-ring Replacement
Parts Ordering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Introduction

Scope of Manual

This instruction manual provides information on the installation, maintenance, and parts ordering for Fisher 685SE and
685SR piston actuators. Refer to separate instruction manuals for information regarding other equipment and
accessories used with these actuators.
Do not install, operate, or maintain 685SE or 685SR 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
Partner before proceeding.

Description

The 685SE and 685SR are medium to large spring­return double­acting piston actuators that provide accurate, high
thrust output for short to long travel applications. These actuators are designed for use with a variety of medium to
large Fisher sliding­stem control valves including the easy­e™, FB, TBX, CVX, HP, EH, and 461.
These actuators feature an internal bias spring that forces the actuator piston rod to extend (685SE) or retract (685SR)
upon a loss of supply pressure, thereby ensuring a fail­closed or fail­open mode of operation. This effectively
eliminates the need for a trip valve and volume tank in most constructions.
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685SE/685SR Piston Actuator
Figure 1. Fisher 685SE Piston Actuator
X0993
Emerson sales office
June 2017
or Local Business