172-65097M-05 (CV10 Control Valve) 7 Oct 2021
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3. Detaching/Reattaching the Coupling Nut and Locknut (Stroke Adjustment)
Supply to the positioner an air pressure that is within the spring range. This will cause
the actuator stem to rise. Remove the coupling nut and locknut while the actuator stem
is in the raised position.
Part
During
Disassembly
During Reassembly
Locknut/
Coupling
Nut
Holding the
coupling nut
securely with a
wrench, loosen
the locknut;
DO NOT
disassemble with
the valve in
contact with the
valve seat, make
sure that the
valve is slightly
suspended
DO NOT apply air pressure in that
is in excess of the pressure
supplied during lift adjustment;
consult the table of tightening
torques and tighten to the proper
torque; if the instructions given
below are not followed when
reassembly is carried out,
malfunctions such as insufficient
lift (insufficient flow capacity)
and/or insufficient closing force
(valve leakage) may result; give
the proper attention to the
adjustment procedure
Instructions for Reverse Action Stroke Adjustment
1. Make sure that the valve is securely seated in the valve seat. (Fig. 1)
2. Supply the spring range
’s maximum air pressure to the actuator (refer to the
“Specifications” section). The actuator stem will ascend. Perform the rest of the
procedure with the actuator stem in this raised position. (Fig. 2)
3. Screw the locknut and coupling nut onto the valve stem until they are just short of
coming into contact with the gland retainer.
4. Supply a lift adjustment supply air pressure to the actuator. (Supply pressure that is
0.01 MPa lower than the lower limit value of the spring range pressure (see p. 5).
The lower limit (value) of the spring range pressure varies depending on the valve
specification. Refer to the drawing for the spring range.
The actuator stem will descend lower than in step 2 described above. (Fig. 3)
5. Screw the coupling nut up until it comes into contact with the actuator stem. Hold the
coupling nut securely in place with a tool such as a wrench and tighten the locknut.
(Fig. 4)
6. Shut off the air supply to the actuator.
Adjustment Instructions
– Fig. 1
Adjustment Instructions
– Fig. 2
Adjustment Instructions
– Fig. 3
Adjustment Instructions
– Fig. 4
Coupling
Nut
Locknut
Actuator stem
Valve stem
Actuator stem
ascends
Attach the coupling nut
and locknut
Actuator stem
descends
Tighten the coupling nut
and locknut
