Fisher 685SE and 685SR Piston Actuators0 pages

Product Bulletin

685SE and 685SR Actuators

61.2:685SE/685SR
October 2013

D103791X012

Fisherr 685SE and 685SR Piston Actuators
The 685SE and 685SR are large spring-return,
double-acting 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 fail-closed or fail-open mode of operation.
This effectively eliminates the need for a trip valve and
volume tank in most constructions.
Several configurations are available to cover a wide
range of application requirements. Typical travels
range from 25 to 610 mm (1 to 24 inches) and cylinder
diameters range from 254 to 711 mm (10 to 28
inches).
The 685SE and 685SR can be used with the FIELDVUE™
DVC6200 digital valve controller for throttling
applications, or with switching valves for on­off
control. This actuator can also be fitted with volume
boosters for fast stroking requirements.

24031-12

685SE

24036-12

685SR

Double Acting Construction — Pressure on both
sides of the piston results in stiff, precise
positioning.

Wide Temperature Range — Standard constructions
offer a temperature range of -40 to 93_C (-40 to
200_F), however higher or lower temperatures are
possible. Special constructions can operate as low
as -54_C (­65_F) and as high as 204_C (400_F).

Mechanical Fail Mode — Depending on construction,
an internal bias spring will force the piston rod to
retract or extend upon a loss of supply pressure.

Manual Override — An optional side-mounted
handwheel is capable of extending or retracting the
actuator manually and can be engaged at any
position from full open to full closed.

Features

High Thrust Capability — Maximum thrusts of up to
354 kN (79,000 lbf) can be produced.

Broad Application Coverage — Standard
constructions offer travels of up to 610 mm (24
inches) and cylinder diameters of up to 711 mm
(28 inches). Even larger constructions are available
upon request.

Low Friction — Low friction piston seals and either
chrome plated or fluoropolymer coated cylinder
bores reduce sliding friction and wear.

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