Emerson Fisher 3025 Instruction Manual page 11

Instruction Manual
D251402X012
10. Install the diaphragm casing (key 3) so that the vent and air connection are diametrically opposed. Take care when
lowering the casing around the stem so that the threads do not damage the bushing.
Note
When you replace actuator diaphragms in the field, take care to ensure the diaphragm casing bolts are tightened to the proper
load to prevent leakage, but not crush the material. Perform the following sequence with a manual torque wrench.
CAUTION
Over-tightening the diaphragm cap screws and nuts (keys 45 and 46) can damage the diaphragm. Do not exceed 16 NSm
(12 lbfSft) torque.
Note
Do not use lubricant on these bolts and nuts. Fasteners must be clean and dry.
11. Align the diaphragm casings and diaphragm holes. Be sure the vent and air connection on the diaphragm casings
are still diametrically opposed. Install the cap screws and nuts (keys 45 and 46). Tighten the diaphragm cap screws
and nuts in the following manner.
12. The first four bolts tightened should be diametrically opposed and 90 degrees apart. Tighten these four bolts to 8
NSm (6 lbfSft).
13. Tighten the remaining bolts in a clockwise, crisscross pattern to 8 NSm (6 lbfSft).
14. Repeat this procedure by tightening four bolts, diametrically opposed and 90 degrees apart, to a torque of 16
NSm (12 lbfSft).
15. Tighten the remaining bolts in a clockwise, crisscross pattern to 16 NSm (12 lbfSft).
16. After the last bolt is tightened to 16 NSm (12 lbfSft) all of the bolts should be tightened again to 16 NSm (12 lbfSft)
in a circular pattern around the bolt circle.
17. Once completed, no more tightening is recommended.
18. Coat the thread of the four cap screws (key 32) and the internal threads of the diaphragm casing (key 3) with
anti-seize lubricant (key 202). Be sure that the cap screw beds into the spring seat are still aligned with the internal
threads of the diaphragm casing. Then install and screw alternately and slowly the four cap screws to compress the
spring.
19. Place the retaining ring (key 59) onto the stem. Install the ring (key 61) and slide the retaining ring and bend it on
the ring.
20. Place the gasket (key 72) and the flange (key 34). Insert the cap screws (key 36) and tighten them.
21. If used, screw travel stop on the stem (keys 66).
22. Place the spacer if used (key 67), the gasket (key 71) and the lifting lug cap (key 40) onto one of the diaphragm
casings according to the actuator action (air-to-close: key 1, air-to-open: key 3). Insert the cap screws (key 44) and
tighten them.
23. If removed, place the travel stop (key 41) into the lifting lug cap.
24. If the actuator is equipped with a side-mounted handwheel, it is necessary to adjust the actuator travel stop
before mounting the actuator onto the side-mounted handwheel. Perform the Travel Stop Adjustment in
accordance with the procedures in the Installation section. Then refer to the Side-Mounted Handwheel Assembly
3025 Actuator
May 2011
11