Removing The 3722 Converter; Removing The Positioner - Emerson Fisher 3710 Instruction Manual

Instruction Manual

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The optional beacon indicator uses a retaining ring (e‐clip) (key 12) on the outside of the positioner cover. The retaining ring holds

the extension shaft. After removing the beacon indicator, remove the external retaining ring to free the extension shaft.

3. Remove the internal or external retaining ring that holds the indicator/extension shaft. Remove the

indicator/extension shaft from the positioner cover.

4. Install the new indicator/extension shaft and secure it with the retaining ring. Install other indicator parts and

properly align the indicator using the procedure given in this instruction manual.

See figure 24.

Figure 24. Removing the Converter Mounting Screws

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REMOVING ONE OF THE TWO MOUNTING SCREWS

1. Be sure all safety procedures have been followed. Remove the input wiring and supply connection from the installed

3722 housing.

2. Remove the two mounting screws (key 84) and carefully separate the converter from the positioner base plate.

Locate the two O‐rings (key 85) and inspect them. Save or replace as necessary.

3. Be sure the input and supply ports in the positioner base plate are clean. Apply sealant (key 64) to the threads of any

pipe nipples or other connectors to be installed in the ports in the positioner base plate. Connect pneumatic input

and supply pressure to the positioner, if necessary.

1. If you are planning to remove a 3720 positioner, be sure to turn off electric power to the 3722 converter.

Disconnect field wiring. Release all pressure to the positioner. Disconnect the supply, instrument, and output

tubing.

2. Unscrew the four captive cover screws (key 8) and remove the positioner cover assembly (key 7).

3. Unscrew the three socket head screws (key 46) and remove the positioner.

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SEPARATING THE CONVERTER FROM THE

POSITIONER BASE PLATE

3710 and 3720 Positioners

September 2017

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