Cashco C27 - C53 Actuator - Manual (Page 8)

8 8 IOM-C27-C53 IOM-C27-C53
4. Actuator can not deliver full stroke.
Symptom Cause-Remedy
A. Valve can not fully close for “Direct Action-ATC-FO”
arrangement; or valve can not fully open for “Reverse
Action-ATO-FC” arrangement. A1.
A2.
A3.
A4.
A5.
A6.
A7.
Insuffi cient air supply pressure. Check Technical Bulletin
for proper air supply pressure.
Manual handwheel out of “neutral” position.
If equipped with a pneumatic positioner, positioner maybe
in “bypass” mode.
Excessive pressure drop. Check technical bulletin of
control valve for maximum allowable ∆P.
Bench range not properly calibrated. Check calibration or
stem overall length and re-calibrate per valve instructions.
Restriction in air supply line limiting volume available
Restriction in valve. Gain access to the valve’s internals
for any debris.
B. Valve can not fully open for “Direct Action-ATC-FO”
arrangement; or valve can not fully close for “Reverse
Action-ATO-FC” arrangement. B1.
B2.
B3.
B4.
B5.
B6.
B7.
Insuffi cient air supply pressure. Check Technical Bulletin
for proper air supply pressure.
Manual handwheel out of “neutral” position.
If equipped with a pneumatic positioner, positioner maybe
in “bypass” mode.
Excessive pressure drop. Check technical bulletin of
control valve for maximum allowable ∆P.
Bench range not properly calibrated. Check calibration or
stem overall length and re-calibrate per valve instructions.
Restriction in air supply line limiting volume available
Restriction in valve. Gain access to the valve’s internals
for any debris.