Emerson FISHER GX Instruction Manual page 6

GX Valve and Actuator
seven installed radially around the diaphragm plate
(key 11). Seven small springs (key 12) should be
installed inside the large springs (key 13) which are
located radially around the diaphragm plate. There is
no small spring at the center of the diaphragm plate
(key 11).
5. Install the upper diaphragm casing (key 9) so that
the ribs on the top of the upper diaphragm casing
are perpendicular with the yoke legs.
6. Apply anti-seize lubricant to the threads.
D For size 225 and 750 actuators, install the 2
long cap screws (key 16) and hex nuts (key 18) 180
degrees apart from each other and in line with the
actuator yoke legs.
D For size 1200 actuators, install the 4 long cap
screws (key 16) and hex nuts (key 18) 90 degrees
from each other, with two of them in line with the
actuator yoke legs.
7. Tighten the long cap screws (key 16) and hex
nuts (key 18), alternating between them to gradually
compress the springs, until the two casing halves
and diaphragm touch.
8. Apply anti-seize lubricant to the threads and
install the remaining short cap screws (key 17) and
hex nuts (key 18) to the casing.
9. Tighten the actuator casing cap screws evenly
using a cross-tightening procedure. Torque to 55
NSm (40 lbfSft).
10. If you had previously removed the actuator
assembly from the valve, place the actuator
assembly back onto the valve body (key 1). Install
the four body nuts (key 7), but tighten them only
finger-tight.
11. Connect a separate air supply to the actuator air
supply connection (as shown on the yoke in figure
15 or 16) and apply sufficient air pressure to raise
the actuator rod (key 22) to the travel stop.
Note: If converting from air-to-close to
air-to-open action, first move the vent cap (key
21) from the air supply connection on the yoke
leg (see figure 17 or 18) to the top of the casing
(see figure 15 or 16).
12. With the valve plug/stem (key 3) on the seat,
thread the stem adjustor nut (key 27) up until it is the
rated travel distance specified in table 2 from the
actuator rod (key 22). Thread the locknut (key 28) up
against the stem locknut and tighten.
6
13. Stroke the actuator rod until it contacts the stem
adjuster nut (key 27) 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.
14. Align the pointer of the travel indicator (key 26)
with the appropriate mark on the travel scale.
15. Tighten the stem connector cap screws (key
25) to 24 NSm (18 lbfSft).
16. For standard bonnet constructions (figures
15, 16, 17, and 18), tighten the body nuts (key 7)
evenly using a cross-tightening procedure. See table
3 for torque requirements.
For extension and bellows bonnet constructions
(figures 19, and 20), tighten the bonnet nuts (key
46) evenly using a cross-tightening procedure. See
table 4 for torque requirements.
17. Release the actuator pressure.
18. Note: For air-to-open action, the air supply
tubing must be connected to the actuator yoke
at the air supply connection, see figure 15 or 16.
(If converting from air-to-close to air-to-open, the
tubing will need to be re-routed to this location).
Actuator Assembly For Air-to-Close
Constructions (or to Change Action to
Air-to-Close - see figure 17 or 18)
1. Position the upper diaphragm casing (key 9)
upside down on the bench so that it lays flat and not
off balance.
Note: If converting from air-to-open to
air-to-close action, first move the vent cap (key
21) from the top of the casing (see figure 15 or
16) and thread into the air supply connection on
the yoke leg (see figure 17 or 18).
2. Install the diaphragm (key 10) on the diaphragm
plate (key 11). Place the washer (key 15) over the
center hole of the diaphragm, so that the convex part
of the washer is facing down toward the diaphragm.
3. Insert the cap screw (key 14) through the washer
and diaphragm, install the actuator spacer (key 13),
and screw the actuator rod (key 22) onto the cap
screw (key 14) finger-tight.
4. Radially align the spring locators in the
diaphragm plate assembly (key 11) with the casing
cap screw holes in the diaphragm (key 10). This will
ensure that the springs do not cover the air path in
the yoke.
Instruction Manual
Form 5770
June 2006