172-65727MA-01 (CV-COS-16) 7 Oct 2021
11
Disassembling/Reassembling the Valve and Actuator Sections
Perform the following procedure before beginning disassembly:
1. After connecting the air piping, operate the air pressure reducing valve to maintain
the positioner air supply pressure at 0.38 MPaG (54 psig).
2. Connect a current generator or a controller for an operation signal input of 4 to 20
mA.
3. Switch the positioner/actuator to manual mode to separate the valve from the
actuator. See the instruction manual for the positioner and actuator for details.
Part
During Disassembly
During Reassembly
—
Set the operation signal input to 12 mA
(50%)
Make sure the gap between the valve
stem and the actuator stem is open
Set the operation signal input to 12
mA (50%)
Make sure the gap between the valve
stem and the actuator stem is open
Valve
Bonnet Nut
Remove with an open-end wrench
Consult the table of tightening torques
and tighten to the proper torque
NOTE: Be careful not to pinch your fingers between the valve stem and actuator stem!
Disassembling/Reassembling of the Body Section
Part
During Disassembly
During Reassembly
Guide Bushing Loosen slightly with a socket wrench
to make the following procedure
easier
Consult the table of tightening
torques and tighten to the proper
torque
Nuts for flange Remove with a socket wrench
Tighten the nuts evenly, while
checking to make sure that there is
no catching or biting when the valve
plug is seated in the valve seat; after
tightening to the rated torque, check
to make sure that the valve plug &
stem moves up and down smoothly;
make sure to tighten them evenly
Continued on the next page
Valve Bonnet
Nut
The actuator unit
orientation can
be changed.
