Samson 3271, Original Instructions Manual, Page: 51 / 72

EB 8310-6 EN 9-9
Service and conversion work
9.5 Conversion work
See Fig. 3-1 and Fig. 3-2 in the 'Design and
principle of operation' section
9.5.1 Reversing the direction
of action (fail-safe
action)
See Fig. 9-5
The direction of action (and fail-safe action)
of pneumatic actuators can be changed. The
fail-safe action is indicated on the nameplate
by a symbol:
Actuator stem extends
Actuator stem retracts
a) Reversal of the direction of
action from stem extends to
stem retracts
1. Lift off the top diaphragm case (A1) and
remove springs (A10).
2. Pull the diaphragm plate assembly con-
sisting of the diaphragm plate (A5), dia-
phragm (A4) and actuator stem (A7) out
of the bottom diaphragm case (A2).
3. Clamp the bottom section of the actuator
stem (A7) into a vise using protective
jaws. Make sure that the actuator stem is
not damaged.
4. Unscrew and remove the collar nut
(A15), while holding the nut (A9) station-
ary.
Malfunction due to loosened nut (A9).
The nut (A9) on the actuator stem serves to
adjust the dimension x.
Î
Do not undo the nut (A9).
Î
If the nut (A9) has been loosened, read-
just the dimension x as specified in Table
9-1.
5. Remove the diaphragm plate (A5) with
diaphragm (A4) from the actuator stem
and place them back on in reverse order.
6. Tighten the retaining nut (A82) while
holding the nut (A9) stationary. Observe
tightening torques.
7. Unscrew the distance piece (A87).
8. Apply a suitable lubricant to the actuator
stem (A7).
9. Clamp the top diaphragm case (A1) with
the opening facing upward into a suit-
able clamping fixture.
10. Place the diaphragm plate assembly to-
gether with the actuator stem (A7) point-
ing upward into the diaphragm case
(A1).
11. Place the springs (A10) in the diaphragm
plate (A5), centering them in the intend-
ed recesses.
12. Carefully guide the bottom diaphragm
case (A2) over the actuator stem (A7)
and place it on the springs (A10). Make
sure that the sealing elements are not
damaged. Ensure that the compressed
air connections on the cases (A1, A2)
are correctly aligned with each other.
NOTICE !