Installing The Stem Connector Assembly - Emerson Fisher 3025 Instruction Manual

Instruction Manual
D251402X012
5. If the travel span is not correct, a wrong or damaged spring has been installed in the actuator. To obtain the correct
spring sizing information, refer to Fisher Catalog 14, Actuator Sizing and Sample Calculations to determine the
correct spring selection for your application. Or contact your Emerson Process Management sales office for
assistance. After replacing the spring, repeat the steps above.

Installing the Stem Connector Assembly

When installing the stem connector assembly, the actuator and valve stem threads should engage the threads of the
stem connector by a distance of the
diameter of the stem.
1. If necessary, push the valve stem down so that it is touching the seat ring.
2. For an air-to-open actuator only, set the diaphragm loading pressure to approximately 0.5 bar over the upper
bench set pressure. The actuator stem should be contacting the upper travel stop.
3. For the size P900 only, screw the actuator and valve stem locknuts away from the connector halves locations.
4. Screw the two stem connectors halves (keys 78 and 79) onto the valve stem and actuator stem. Then place the
travel indicator (key 84), the spacer if used (key 86) and the anti-rotator (key 85) on the valve stem connector half.
5. To adjust the travel, perform one of the following procedures as appropriate:
a. If the actuator is equipped with a side-mounted handwheel: turn the handwheel so that the distance between
the anti-rotator and the actuator stem connector half is equal to the valve travel. Be sure the actuator stem does
not rotate while turning the handwheel (use the anti-rotator to prevent rotation). Be sure that the actuator and
valve stem threads are engaging the threads of the stem connectors by the distance of at least one diameter of
the stem.
b. If the actuator is not equipped with a side-mounted handwheel: rotate the connector halves so that the distance
between the anti-rotator and the actuator stem connector half is equal to the valve travel. Be sure that the
actuator and valve stem threads are engaging the threads of the stem connectors by the distance of at least one
diameter of the stem.
CAUTION
Incomplete engagement of the stem connector onto either the valve stem or actuator stem can result in stripped threads
or improper operation. Be sure that the length of the actuator stem or the valve stem in the connector is equal or greater
than the diameter of that stem. Damage to threads on either stem or in the stem connector can cause the parts to be
replaced prematurely.
6. Perform one of the following procedures as appropriate:
a. For an air-to-open actuator: Slowly decrease the diaphragm pressure and line up the stem connector halves.
b. For an air-to-close actuator: Slowly increase the diaphragm pressure and line up the stem connector halves.
7. Install the cap screws (key 87) with the lock washers if used and tighten them.
8. For sizes P460, P462 and P460-200, install the cap screws (key 80) and the nuts (key 81) and tighten them. For the
size P900, screw the valve and actuator stem locknuts against the stem connector halves.
9. Slowly increase and decrease pressure several times, stroking the valve from the lower bench set pressure to the
upper pressure.
10. Adjust the travel indicator scale (key 74) to correspond with the travel indicator. Stroke the valve full travel to
ensure that the travel matches the valve travel on the travel indicator plate. If travel is not correct repeat the stem
connector procedure.
3025 Actuator
May 2011
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