Samson 3372 Mounting and operating instructions - (350 Cm²)
36
EB 8313-3 EN
Maintenance of Type 3372 (350 cm²)
7 Maintenance of Type 3372
(350 cm²)
Fig. 16
Parts subject to wear may need to be re-
placed if the actuator does not work proper-
ly.
Note
We recommend the following tools
and resources for maintenance:
−
Socket wrench (width across flats
27) for 350 cm² version
−
Lubricant: Order no. 8152-0043
−
Thread-locking fluid: Order no.
8121-3010
−
Mandrel or hook to remove seals
−
Piece of pipe to mount seals and
plain bearings
−
Torque wrench
Before performing any maintenance work,
the actuator must be removed from the valve.
Î
Detach the electrical and pneumatic con-
nections from the positioner. Remove the
external piping from the positioner to the
top of the actuator with fail-safe action
„actuator stem retracts“ (FE).
7.1 Removing the actuator
The actuator must be dismantled to replace,
for example, damaged seals or plain bear-
ings. A defective diaphragm additionally re-
quires the dismantling of the diaphragm
plate assembly.
7.1.1 Reducing the spring pre-
loading
Î
Unscrew and remove the hex nuts on the
short bolts on the diaphragm casing.
Î
Unthread the hex nuts on the long bolts a
few turns, alternating between them to
gradually release the spring preloading.
7.2 Removing the diaphragm
plate assembly
Î
Liftoffthetopdiaphragmcase(1).
Î
Remove all springs (10) in the actuator
with fail-safe action „actuator stem ex-
tends“ (FA).
Î
Take the diaphragm plate (5) together
with the diaphragm (4) and actuator
stem (7) out of the bottom diaphragm
case.
Î
Remove the springs (10) now accessible
in the actuator with fail-safe action „ac-
tuator stem retracts“ (FE).
Î
Liftandtakethediaphragmplateassem-
bly out of the bottom diaphragm case.