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NoteOlder GX actuator nameplates do notcontain spring configuration information. If you require replacement springs or wish to switch to anoptional actuator construction, consultyour Emerson Process Management sales office.NoteWhen the GX actuator is equipped withthe integrated FIELDVUE DVC2000 Series digital valve controller (figure1), additional considerations may berequired. Refer to the FIELDVUE DVC2000 Digital Valve ControllerMounting section of this manual foradditional instruction.

Instruction Manual

GX Control Valve and Actuator System - 14722 GX Valve and Actuator

February 2009 instructions in this manual to ensuresafe removal of the actuator from thevalve. Use lock-out procedures to besure that the above measures stay in effect while you work on theequipment. The valve packing box maycontain process fluids that arepressurized, even when the valve hasbeen removed from the pipeline .Process fluids may spray out underpressure when removing the packinghardware or packing rings, or when loosening the packing box pipe plug. Check with your process or safetyengineer for any additional measuresthat must be taken to protect againstprocess media.NoteWhenever a gasket seal is disturbedby removing or shifting gasketedparts, install a new gasket during reassembly. This ensures a goodgasket seal because the used gasketmay not seal properly.

Actuator Disassembly (For Air-to-OpenConstructions - see figures 18 or 19)

1. Connect a separate air supply to the lowerdiaphragm casing via the air supply connection onthe yoke (as shown in figure 18 or 19) and apply sufficient air pressure to raise the valve plug/stem offthe seat to mid-travel.2. Remove the stem connector nut half (key 23),stem connector bolt half (key 24), and travelindicator (key 26).3. Push the valve plug/stem (key 3) down until itcontacts the seat.4. Loosen the locknut (key 28) and thread the stemadjustor nut (key 27) down until it clears the top ofthe valve plug/stem (key 3).5. Shut off the air pressure and disconnect theseparate air supply to the lower diaphragm casing(as shown in figure 18 or 19).

Actuator Maintenance

The following sections provide procedures foractuator maintenance. Refer to figures 18, 19, 20,and 21.The actuator soft parts may require periodicreplacement. This includes the diaphragm (key 10),actuator rod bushing (key 19), and the actuator rod seal (key 20).If the actuator stroking direction (air-to-open orair-to-close) is unknown, refer to the nameplate on top of the actuator casing and figure 2.There are several optional actuator constructions,depending on supply pressure. Refer to thenameplate on the top of the actuator to determinethe construction installed. Refer to figure 3 and table 2 for proper spring configuration.

WARNING

To avoid personal injury or propertydamage due to actuator springs (keys 12 and 82) being under compression, remove the long cap screws (key 16)last.The upper actuator casing may remainfixed to the diaphragm and lowercasing during disassembly, even if thecasing cap screws have been loosened. If this happens, the actuator
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