Instruction Manual
D103312X012
GX 3-Way Valve and Actuator
July 2017
6
The following sections provide procedures for actuator maintenance. Refer to figures 8, 11, and 13.
The actuator soft parts may require periodic replacement. This includes the diaphragm (key 10), diaphragm O-ring
(key 109), actuator rod bushing (key 19), and the actuator rod seal (key 20).
Note
When the GX 3‐Way actuator is equipped with the integrated FIELDVUE DVC2000 digital valve controller (figure 1), additional
considerations may be required. Refer to the FIELDVUE DVC2000 Digital Valve Controller quick start guide,
mounting instructions.
Actuator Disassembly (For Fail‐Down Constructions, see figure 11)
1. Connect a separate air supply to the lower diaphragm casing via the air supply connection on the yoke (as shown in
2. Remove the stem connector nut half (key 23), stem connector bolt half (key 24), and travel indicator (key 26).
3. Push the valve plug/stem (key 3) down until it contacts the seat.
4. Loosen the locknut (key 28) and thread the lower stem connector (key 27) down until it clears the top of the valve
plug/stem (key 3).
D
For HT construction,
loosen locknut (key 108) and thread the stem extension (key 106) down as far as possible
5. Shut off the air pressure and disconnect the separate air supply to the lower diaphragm casing (as shown in figure
WARNING
To avoid personal injury or property damage due to actuator springs (key 12) being under compression, remove the long
cap screws (key 16) last.
The upper actuator casing may remain fixed to the diaphragm and lower casing during disassembly, even if the casing cap
screws have been loosened. If this happens, the actuator springs are still under compression. The upper casing could
suddenly come loose and jump, due to the compressed energy of the springs. If the upper casing is stuck to the diaphragm
and lower casing when you begin loosening the casing cap screws, pry the casings apart with a prying tool. Always ensure
that the springs are dispersing energy and the upper casing is moving against the long bolts during disassembly.
6. Remove the
short
actuator casing cap screws and hex nuts (keys 17 and 18) first. Once these have been removed
from the actuator assembly, carefully remove the
long
actuator cap screws and hex nuts (keys 16 and 18),
alternating between them to gradually release the spring energy (compression).
7. Remove the upper diaphragm casing (key 9) and the actuator springs (key 12).
8. Lift off the actuator stem/diaphragm assembly (includes keys 22, 11, 10, 14, 13, 109, and 15) and remove the cap
screw (key 14), actuator spacer (key 13), actuator rod (key 22), and washer (key 15).
9. Replace the diaphragm (key 10), actuator rod bushing (key 19), actuator rod seal (key 20), and diaphragm O-ring
(key 109), as needed.
Actuator Disassembly (For Fail‐Up Constructions, see figure 8)
sufficient air pressure to move the plug/stem to mid‐travel.