Travel Stop Adjustment - Emerson Fisher 3025 Instruction Manual

3025 Actuator
May 2011
2. Lift or hoist the actuator onto the valve bonnet:
a. For the 3-9/16 yoke boss: Slowly lower the actuator down onto the valve. As the yoke passes over the end of the
valve stem, place the yoke locknut over the valve stem. Once the actuator is in place, screw the yoke locknut
onto the valve bonnet and tighten the locknut.
b. For all other yoke bosses: Slowly lower the actuator down onto the valve. Once the actuator is in place, insert the
cap screws and tighten the hex nuts, securing the actuator to the bonnet.

Travel Stop Adjustment

The actuator is normally shipped adjusted at the factory and you may refer directly to the Installing the Stem
Connector Assembly procedures.
If the actuator has been disassembled, it is necessary to adjust the travel stop. You may perform the following
procedure before connecting the actuator stem to the valve stem.
WARNING
When moving the actuator stem with loading pressure applied, exercise caution to keep hands and tools out of the
actuator stem travel path. If the loading pressure is accidentally disconnected, personal injury and property damage is
possible if something is caught between the actuator stem and other control valve parts.
Also provide a certified pressure gauge suitable to accurately read the diaphragm pressure from 0 through the upper
bench set pressure marked on the nameplate. Apply loading pressure to the diaphragm.
Stroke the actuator a few times to ensure that the pressure gauge is working correctly, and that the actuator is
functioning properly. It is important to be sure that the actuator assembly is not binding or producing any loading
friction on the actuator stem movement.
Note
For push-down-to-close valves, the valve plug is the limit for downward travel and the actuator up-stop is the limit for upward
travel (away from the valve).
1. If not already accomplished, provide a temporary means of applying adjustable loading pressure to the actuator
during the travel stop adjustments.
2. Remove the cap (key 43, figures 3 through 6) or loosen the locknut (key 42, figures 7 through 12). Unscrew the
travel stop (key 41).
3. Perform one of the following procedures as appropriate:
a. For an air-to-open actuator: apply the upper bench set loading pressure to the diaphragm. Adjust the travel stop
(key 41) so that it touches the actuator stem. Then lock the travel stop by replacing the cap (key 43) or by
tightening the locknut (key 42).
b. For an air-to-close actuator: apply the lower bench set loading pressure. The actuator should show movement at
the lower bench set pressure. Adjust the travel stop (key 41) so that it touches the actuator stem. Then lock the
travel stop by replacing the cap (key 43) or tightening the locknut (key 42).
4. Stroke the actuator and check that the actuator is capable of the travel shown on the travel indicator scale (key 74).
If the travel span is correct, travel stop adjustment is complete. Proceed to the Installing the Stem Connector
Assembly subsection.
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Instruction Manual
D251402X012