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Installation, Operation and Maintenance Manual
MAN 575 Rev. 4
July 2020
15
Operation and Use
Section 3: Operation and Use
Modulating service
When modulating control is required as a function of a pneumatic or electric control signal,
a positioner (5) is used, which controls the supply to the actuator cylinder to keep the valve
in the required angular position. The positioner has a mechanical linkage to the actuator,
for a feedback of the valve position.
Figure 11
electropneumatic
positioner
pneumatic
positioner
pneumatic
control signal
electric
control signnal
pressurized air (supply)
reduced pressure air (opening chamber)
reduced pressure air (closing chamber)
3.2
Residual Risks
!
WARNING
The actuator has parts under pressure. Use the due caution. Use the due caution.
Use individual protections provided for by the laws and provisions in force.
3.3
Operations
The operations are carried out sending the proper signal through the control system in
compliance with Customer specifications.
Please refer to the functional diagram and specific documentation supplied.
