Mounting The Actuator On The Valve After Service Or Conversion Work; Service Work; Replacing The Diaphragm - Samson 3371 Mounting And Operating Instructions

Note
To remove an actuator with "stem extends"
fail-safe action and/or with preloaded
springs, a certain signal pressure must be
applied to the actuator (see the 'Removal'
section). Afterwards, the signal pressure
must be removed and the air supply discon-
nected again and locked.
4. Relieve the compression from the pre-
loaded springs. See 'Relieving the spring
compression in the actuator' in the 'Re-
moval' section.
5. Unthread and remove the nuts and bolts
(including the washers) from around the
actuator casing.
The following service and/or conversion
work can be performed after preparation is
completed:
− Replace the diaphragm (see sec-
tion 9.4.1)
− Reverse the direction of action (see sec-
tion 9.5.1)
9.3 Mounting the actuator on
the valve after service or
conversion work
1. Mount the actuator (see the 'Installation'
section).
2. Adjust the upper or lower bench range
values (see the 'Start-up' section).

9.4 Service work

See Fig. 9-1 and Fig. 9-2
EB 8317 EN
9.4.1 Replacing the dia-
phragm
a) 120 cm² actuator area
Actuator stem extends
1. Lift off the top diaphragm case (A16)
and remove springs (A10).
2. Pull the actuator stem (A3) together with
the diaphragm plate (A14), diaphragm
(A18) and diaphragm plate (A13) out of
the bottom diaphragm case (A2).
3. Unscrew the collar nut (A26).
4. Remove the diaphragm plate (A14), dia-
phragm (A18) and diaphragm plate
(A13) from the actuator stem (A3).
5. Place the new diaphragm on the dia-
phragm plate (A13). Place on the dia-
phragm plate (A14).
6. Check the sealing element on the collar
nut (A26). If necessary, renew it.
7. Tighten the collar nut (A26). Observe
tightening torques.
8. Apply a suitable lubricant to the actuator
stem (A3).
9. Place the actuator stem (A3) together
with the diaphragm plate (A14), dia-
phragm (A18) and diaphragm plate
(A13) in the bottom diaphragm case
(A2). Make sure that the radial shaft seal
(A40) is not damaged.
10. Place the springs (A10) into the bottom
diaphragm case, centering them in the
intended recesses.
Servicing and conversion
9-3