Installation, Mounting, And Connections; Installation - Fisher 3570 Instruction Manual

Instruction Manual
D200137X012

Installation, Mounting, and Connections

Installation

WARNING
D Always wear protective clothing, gloves, and eyewear when performing any installation operations to avoid personal
injury.
D Personal injury or property damage may result from fire or explosion if natural gas is used as the supply medium and
preventive measures are not taken. Preventive measures may include, but are not limited to, one or more of the
following: Remote venting of the unit, re‐evaluating the hazardous area classification, ensuring adequate ventilation,
and the removal of any ignition sources. For information on remote venting of this positioner, refer to page 8.
D Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
D If installing this into an existing application, also refer to the WARNING at the beginning of the Maintenance section of
this instruction manual.
The positioner is usually mounted on the actuator at the factory. However, if the positioner and actuator are ordered
separately, it is necessary to mount the positioner on the actuator. Before mounting the positioner, be certain the
O‐ring (key 33, figure 10) is in place in the cylinder (top connection) in the base of the positioner.
For appropriate actuator/positioner combinations, refer to the positioner type number descriptions given earlier in
this instruction manual.
D For 3570, 3570C, 3572, and 3573 positioners, mount the positioner with two cap screws (key 32, figure 10). If the
range and bias springs are not installed in the positioner, refer to the range spring and bias spring procedures in the
Maintenance section.
Insert the threaded end of the spring retainer (key 19, figure 2) into the center of the range spring (see figure 2). Then,
insert a screwdriver into the center of the range spring and extend the spring until the spring retainer can be screwed
into the top of the actuator piston rod extension. Tighten the spring retainer into the top of the actuator piston rod
extension. If the range spring and/or bias spring is not installed in the positioner, refer to the procedures for either
spring in the Maintenance section.
D For 3570P and 3570PC positioners, attach the positioner extension and positioner to the cylinder mounting plate
with the two cap screws (key 100, figure 13). Make the required pressure connections as described in the following
procedure. Go to the initial range spring extension procedures for 3570P and 3570PC positioners.
D For 3571, 3576, and 3577 positioners, insert two cap screws through the holes in the mounting bracket (key 55,
figure 12) to attach the positioner to the actuator mounting boss. Attach the hex drive stud to the actuator‐valve
stem connection. Attach the end bearing (key 56E, figure 12) to the hex drive stud.
3570 Positioners
September 2015
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