Instruction Manual
D103175X012
GX Valve and Actuator
April 2011
7
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.
2. 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).
3. Remove the upper diaphragm casing (key 9).
4. Lift off the actuator stem/diaphragm assembly (includes keys 22, 11, 10, 14, 13, and 15) and remove the cap screw
(key 14), actuator spacer (key 13), actuator rod (key 22), and washer (key 15).
5. Remove the actuator springs (key 12 and/or 82).
6. Replace the diaphragm (key 10), actuator rod bushing (key 19), and actuator rod seal (key 20), as needed.
Table 2. Actuator Spring Configuration Based on Minimum Supply Pressure
(1)
ACTUATOR SIZE
TRAVEL
STEM MATERIAL
MINIMUM SUPPLY
PRESSURE
SPRING CONFIGURATION
mm
Air‐to‐Open
Air‐to‐Close
225
20
S20910, N05500
S31603
4 bar (58 psi)
A6
A3
A4
(2)
A4
(2)
3 bar (44 psi)
A4
A3
2 bar (29 psi)
A3
A2
225
20
S31803, N10665,
N06022
4 bar (58 psi)
A6
A3
3 bar (44 psi)
A4
A3
2 bar (29 psi)
A3
A2
750
20
S20910, N05500
S31603
4 bar (58 psi)
B6
B4
B6
(2)
B6
(2)
3 bar (44 psi)
B6
B4
2 bar (29 psi)
B4
B4
750
20
S31803, N10665,
N06022
4 bar (58 psi)
B4
B4
3 bar (44 psi)
B4
B4
2 bar (29 psi)
B4
B4
750
40
S20910, N05500
S31603
4 bar (58 psi)
C12
C6
3 bar (44 psi)
C8
C3
2 bar (29 psi)
C4
C3
750
40
S31803, N10665,
N06022
4 bar (58 psi)
C8
C6
3 bar (44 psi)
C8
C3
2 bar (29 psi)
C4
C3
1200
40 or 60
S20910, N05500
S31603
4 bar (58 psi)
D15
D15
3 bar (44 psi)
D15
D15
2 bar (29 psi)
N/A
N/A
1. Only applicable to actuators with spring information on the nameplate (see figure 2).
2. Only applicable to Cavitrol III constructions.
Table 3. Fisher GX Maximum Rated Travel
ACTUATOR SIZE
NUMBER OF CASING BOLTS
TRAVEL
mm
225
6
20
750
10
20 or 40
1200
16
40 or 60