Samson 3248-1, Mounting And Operating Instructions

Page: 6 / 16

2 Assembling and adjusting
valve and actuator
If the valve and actuator have not been pre-
assembled by the manufacturer or in the
case that the original actuator attached to
the valve is to be replaced by another actua-
tor of a different type or size, proceed as
follows:
Removing a mounted actuator
Note!
For actuators with fail-safe action "Actuator
stem extends" and especially actuators with
pretensioned springs, apply a pressure
slightly higher than the lower signal pressure
range (see actuator nameplate) to the
loading pressure connection on the bottom
diaphragm chamber, before loosening the
annular nut (8.2).
4
Remove clamps of the stem connector (7)
between the actuator and plug stem ex-
tension and unscrew annular nut (8.2).
4
Lift the actuator off the valve.
Mounting the actuator
1. Loosen the lock nut (6.2) and stem con-
nector nut (6.1) on the valve. Firmly
press the plug with the plug stem into the
seat. Then thread down the lock nut and
stem connector nut.
2. Remove clamps of the stem connector (7)
and annular nut (8.2) on the actuator
(8).
3. Slide the annular nut over the plug stem
extension.
4. Place the actuator on the valve bonnet
(5) and screw tight using the annular nut
(8.2).
5. Read the nameplate on the actuator to
determine which bench range (signal
range with pretensioned springs) and
which operating mode of the actuator
are used.
The operating mode (fail-safe action) "Actu-
ator stem extends" or "Actuator stem re-
tracts" is indicated on the nameplate by
FA
or
FE
on the Type 3271 Actuator and by the
appropriate symbol on the Type 3277 Actu-
ator.
The lower bench range corresponds to the
lower signal pressure range to be adjusted;
the upper bench range corresponds to the
upper signal pressure range.
6. For actuators with fail-safe action "Actu-
ator stem extends" , apply the pressure
corresponding to the lower signal pres-
sure range (e.g. 0.2 bar) to the loading
pressure connection on the bottom dia-
phragm chamber.
For actuators with fail-safe action
"Actu-
ator stem retracts" , apply the pressure
corresponding to the upper signal pres-
sure range (e.g. 1 bar) to the loading
pressure connection on the top dia-
phragm chamber.
7. Manually turn the stem connector nut
(6.1) until it touches the actuator stem
(8.1) and then turn it a further 1/4 turn.
Screw tight the lock nut (6.2) while hold-
ing the stem connector nut stationary to
6
EB 8093 EN
Assembling and adjusting valve and actuator