Fisher GX 3-Way, Инструкция по эксплуатации, Страница: 12 / 28

Instruction Manual
D103312X012
GX 3-Way Valve and Actuator
July 2017
12
D
For HT constructions, see figure 12. Install the locknut (key 108) and stem extension (key 106). Install the valve
plug/bonnet sub assembly into the valve body (key 1).
19. Mount the actuator onto the valve and install the body nuts (figure 8 key 7), but tighten them only finger‐tight.
20. For fail‐down constructions, connect a separate air supply to the lower diaphragm casing air supply connection (as
shown in figure 11) and apply sufficient air pressure to raise the actuator rod (key 22) to the travel stop. Proceed to
the next step.
For fail‐up constructions, proceed to the next step.
21. Tighten the valve body nuts (key 7) evenly using a cross‐tightening procedure. See table 3 for torque
requirements.
D
For HT constructions, see figure 12. Ensure the valve body nuts (key 7) are tightened at the valve body (key 1)
and at the top of the yoke extension (key 105).
22. Thread the lower stem connector (key 27) up to match the gap setting between the actuator rod and stem
adjustor nut specified in table 2. Thread the locknut (key 28) up against the stem locknut and tighten to a torque of
48 N
S
m (35 lbf
S
ft) for 10mm stems or 175 N
S
m (129 lbf
S
ft) for 14mm stems.
D
For HT constructions see figure 12. With the valve plug/stem (key 3) on the lower seat, thread the stem
extension (key 106) up to match the gap setting between the actuator rod and stem extension specified in
table 2. Thread the locknut (key 108) up against the stem extension and tighten to a torque of 48 N•m (35
lbf•ft) for the 10mm stems or 175 N•m (129 lbf•ft) for 14mm stems.
23. Stroke the actuator rod until it contacts the lower stem connector (key 27) or stem extension (key 106, figure 12)
and install the stem connector halves and travel indicator (keys 23, 24, and 26) with the cap screws (key 25). Install
the stem connector halves in the proper orientation so that when looking at the inside of the stem connector
halves, the flats are down and the beveled surfaces are up.
24. Align the pointer of the travel indicator (key 26) with the appropriate mark on the travel scale.
25. Tighten the stem connector cap screws (key 25) to 35 N
•
m (26 lbf
•
ft).
26. Tighten the packing follower (key 29) to the torque specified in table 4.
Alternately, the packing follower can be tightened by the following method:
a. Tighten the packing follower until the Belleville springs are compressed 100% (or completely flat), as detected by
a rapid increase in nut torque.
b. Loosen the packing follower 60
_
of rotation.
27. For fail‐down constructions, release the actuator pressure.
28. For fail‐down constructions, ensure the vent (key 21) is installed into the upper diaphragm casing (see figure 11).
29. For fail‐up constructions, ensure the vent (key 21) is installed into the actuator yoke air supply connection. See
figure 8.
Replacing Packing (Electric Actuators)
Isolate the control valve from the line pressure, release pressure from all three inlets/outlets of the valve body and
drain the process media from the valve. Use lock‐out procedures to ensure that the above measures stay in effect
while you work on the equipment.
1. Stroke the actuator so the valve plug/stem (key 3) is at mid travel.
2. Remove the stem connector nut half (key 23), stem connector bolt half (key 24), and travel indicator (key 26).
3. Use precaution to ensure the actuator is locked in position and cannot stroke.
4. Mark the position of the locknut (key 28) on the stem for reassembly.