Bias Spring; Disassembly; Assembly; Parts Ordering - Fisher 3570 Instruction Manual

Instruction Manual
D200137X012

Bias Spring

Disassembly

1. Refer to figure 2. Remove the top E‐ring travel stop.
2. Loosen the locknut securing the bias spring seat in place. Then rotate the adjusting screw until the spring force is at
a minimum.
3. Loosen the locknut that secures the bias spring post to the positioner base. Using a screwdriver in the slot in the top
of the post, unscrew the post from the base.
4. Tilt the bottom of the post out and remove the post from the beam.
5. Remove the locking nuts and the spring seat from the bias spring post.

Assembly

1. Install the new bias spring, spring seat, and locking nuts on the bias spring post.
2. Replace the bias spring post into the beam and install the top E‐ring travel stop.
3. Install the bias spring post into the base. Be certain that the bottom of the post thread is positioned as shown in
figure 2. Ensure that the beam does not rub on the post.
4. For 3570P and 3570PC positioners, go to the initial range spring extension procedures for 3570P and 3570PC
positioners.
5. Adjust the positioner as described in the adjustments procedures.
The action of the positioner can be reversed in the same manner as described in the changing positioner action
procedures. However, before attempting to reverse the action consult your
to determine if a different retainer, different range springs or different bias springs are required. Refer to instruction
manual supplement D104021X012.

Parts Ordering

A serial number is assigned to each positioner. The serial number is stamped on the nameplate. Always refer to the
serial number when corresponding with your
technical information.
WARNING
Use only genuine Fisher replacement parts. Components that are not supplied by Emerson Process Management should
not, under any circumstances, be used in any Fisher instrument. Use of components not supplied by Emerson may void
your warranty, might adversely affect the performance of the valve, and could cause personal injury and property damage.
Emerson Process Management sales office
Emerson Process Management sales office
regarding spare parts or
3570 Positioners
September 2015
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