172-65742MA-01 (CT20/CT20D) 7 Oct 2021
14
Instructions for Direct Action (Air to Close, Fail Open) Stroke Adjustment
1. Make sure that the valve plug is securely seated in the valve seat. (Fig. 1)
2.
Screw the locknut and coupling nut onto the valve stem until they are just short
of coming into contact with the guide bushing. (Fig. 2)
3.
Supply the upper limit air pressure (0.1 MPaG (15 psig, 1.0 barg)) of the spring
range (e.g. 0.02 to 0.1 MPaG (3 to 15 psig, 0.2 to 1.0 barg)) to the actuator. The
actuator stem will descend. (Fig. 3)
NOTE: Be careful not to pinch your fingers.
4.
Turn the stem connector nut until it comes into contact with the actuator stem,
and turn the stem connector nut a further 1/4 turn to contact the actuator stem.
Make sure that the valve plug is seated in the valve seat. Hold the stem
connector nut securely in place with a tool such as a spanner and tighten the
locknut. (Fig. 4)
5.
Shut off the air supply to the actuator.
NOTE: Be careful not to pinch your fingers.
6.
Secure the stem connector nut and the actuator stem with the stem bracket
clamps. Make sure to adjust the stem bracket clamps to 100% (fully open) on
the travel indicator scale. (Fig. 5)
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Actuator Stem
Valve Stem
Locknut
Stem
Connector Nut
Actuator Stem
ascends
Actuator Stem
descends
NOTE:
Be careful
not to pinch
your fingers
Actuator Stem
ascends
Pull up the stem
connector nut and
the valve stem
Stem Bracket
Clamps
Travel Indicator Scale
Travel Indicator Scale
Mounting Bolt
Travel Indicator Scale
Mounting Bolt
