10
EB 8312-2 EN
Design and principle of operation
3 Design and principle of oper-
ation
The Type 3273 Side-mounted Handwheel
with 30 mm travel is suitable for mounting
on Series 240, 250, 280, and 290 Valves or
on suitable interfaces together with the
Type 3271 or Type 3277 Pneumatic Actua-
tors with areas of 175 to 1400-60 cm². A
special version of the side-mounted hand-
wheel can also be used to move the valve on
which a pneumatic actuator is not mounted.
The side-mounted handwheel is mounted be-
tween the valve and actuator. The handwheel
can remain mounted on the valve during
maintenance and repair work or while ex-
changing the pneumatic actuator. The hand-
wheel can be used in this case to move the
valve manually to its closed or open position.
The handwheel can be used to move the
valve manually opposing the spring force of
the pneumatic actuator upon air supply fail-
ure.
The worm shaft unit, consisting of the worm
shaft and worm-geared wheel, is driven over
the handwheel. The spindle nut transfers the
rotary motion to the threaded rod, which
moves the valve. Depending on the direction
of rotation and mounted valve, the threaded
rod extends or retracts.
G6
Handwheel
G7
Handle
G11
Locking bolt
G16
Threaded rod
G63
Spindle nut
G64
Worm shaft
G65
Worm-geared wheel
G11
G16
G6
G63
G64
G65
G7
Fig. 3:
Sectional drawing of Type 3273 Side-mounted Handwheel
