16
October 2020
Installation, Operation and Maintenance Manual
VCIOM-15792-EN Rev. 0
Section 3: Operation and Use
Operation and Use
Figure 10
Bettis GVO LP DA MHP without control system
Pressurize the pneumatic-cylinder chamber, this pressure starts the linear motion of the
piston and the consequent motion of the valve stem that is coupled.
The valve is actuated in opening and in closing position by the actuator pneumatic cylinder
in one direction and by the spring unit in the other direction. Check the correct operation
of the actuator through the visual position indicator.
3.3.2
Electric Remote Control to Open and to Close
When actuator is furnished of control system (panel or cabinet) remote operations
were possible:
•
From the control room send the electric signal corresponding to the operation to
carry out: energize solenoid valve during all the valve stroke.
•
Solenoid valve must be de-energized at the end of actuator operation.
3.3.3
Emergency Manual Operation by MSJ / MHW
(when sufficient line pressure is not available)
•
Engage the manual override by rotating it’s handle.
•
Turn by the lever the manual override clockwise to close, or counterclockwise to open.
•
Check the correct operation of the actuator through the visual position indicator.
•
If no other manual operation is carried out, disengaged the manual override to allow
the operation with pneumatic supply.
(see Section 7.2, Table 14: sectional drawing for Manual Jackscrew MSJ).
