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Type 2920, 2921, 2960, 2961
Product description
5.2.2
Type 2921, 2961
Handwheel with lock
(optional)
Position indicator
Relief bore
•
Wrench flat for open-end
wrench
Globe body
Port connection
Flow direction indicator
Fig. 3:
Example of 2/2-way globe valve, type 2921
5.3
Function
By manually activating the handwheel, the force is transmitted via
a spindle and the valve is opened or closed. The medium in the
valve body is either approved or blocked off. Turning the handwheel
anticlockwise opens the valve, turning it clockwise closes it.
To protect the actuator, we recommend not closing the actuator
with more force than is required to shut off the medium pressure.
The following tightening torques must not be exceeded for the
handwheel sizes: S: 7 Nm, M: 15 Nm, L: 30 Nm.
5.3.1
Position indicator
Fig. 4:
Position indicator
When turning the handwheel anticlockwise, the reproducible
stroke scale becomes visible between the position indicator and
the handwheel.
The visibility of the stroke scale is not directly correlated
with the closed position of the valve. Depending on the
design of the valve, the reproducible stroke scale:
- may not be visible when the valve is open, or
- may be visible when the valve is closed.
The scale on the handwheel determines the rotation position of
the handwheel (50 positions).
The reproducible stroke scale shows, depending on the bottom
edge of the handwheel, the relative position of the valve (valve
english
Handwheel with scale
Reproducible stroke scale
9
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