Instruction Manual
D103312X012
GX 3-Way Valve and Actuator
July 2017
9
12. If you had previously removed the actuator assembly from the valve, place the actuator assembly back onto the
valve body (key 1) or yoke extension (key 105, figure 12) for HT construction. Install the body nuts (key 7) and
tighten 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).
13. With the valve plug/stem (key 3) on the lower seat, 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.
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.
15. Align the pointer of the travel indicator (key 26) with the appropriate mark on the travel scale.
16. Tighten the stem connector cap screws (key 25) to 35 N
S
m (26 lbf
S
ft).
Note
For fail‐up action, the air supply tubing must be connected to the actuator upper casing at the air supply connection, see figure 8.
(If converting from fail‐down to fail‐up, the tubing will need to be re‐routed to this location).
Packing Maintenance
Key numbers refer to figure 7.
Packing Adjustment
For ENVIRO-SEAL
™
spring‐loaded single PTFE V‐ring packing (figure 7) or for ENVIRO-SEAL graphite ULF packing (figure
7), the Belleville spring pack (key 34) maintains a sealing force on the packing. If leakage is detected around the
packing follower (key 29) check to be sure that the packing follower (key 29) is tight. Using a wrench, tighten the
packing follower (key 29) in 1/4 turn intervals until the leakage is stopped. If leakage cannot be stopped in this
manner, proceed to the Replacing Packing section in this manual.
Replacing Packing (Pneumatic 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. Shut off all pressure lines to the actuator and release all pressure from the
actuator. Use lock‐out procedures to ensure that the above measures stay in effect while you work on the equipment.
1.
For fail‐down constructions, as shown in figure 11:
a. Connect a separate air supply to the lower diaphragm casing via the air supply connection on the yoke (as shown