Installation, Operation and Maintenance Manual
VA-DC-000-1878 Rev. 0
December 2020
49
Section 7: Troubleshooting
Troubleshooting
Section 7: Troubleshooting
7.1
Fault Insertion
In the unlikely event of a fault developing, the following Fault Location Table is provided to
assist the service engineer to perform troubleshooting. This Table is designed to cover as
wide a range of Emerson Bettis actuators as possible. Reference to equipment not supplied
should be ignored.
Table 22.
Fault Location Table
Symptom
Potential Causes
Remedy
Erratic movement
Irregular supply of
operating medium
Check operating medium for consistent supply
pressure and correct as necessary.
Inadequate lubrication
Dismantle, relubricate and reassemble.
Worn parts
Dismantle, visually inspect for significant wear.
Actuator replacement may be required.
Defective valve
Consult the valve OEM's documentation.
Short stroke
Incorrectly set stops
(valve and /or actuator)
Check the position of the travel stops and
readjust as necessary.
Hardened grease
Dismantle, remove any hard grease,
relubricate and reassemble.
Debris left in the cylinder or
housing during maintenance
Disassemble cylinder assembly to remove
debris. Reassemble cylinder assemble
as necessary.
Defective valve
Consult the valve
manufacturer's documentation.
Apparent lack of
torque
Inadequate supply pressure
Ensure supply pressure is above the minimum
operating pressure of the actuator and that
output torque produced at supply pressure
exceeds valve torque demand.
Incorrect speed
control settings
Adjust speed controls to increase flow.
Exhaust port blocked
Remove and clean the exhaust port silencers
and replace.
Pipe work blocked,
crushed or leaking
Examine the pipe work for blockages, crushed
pipe or leakage. Clear or replace as necessary.
Defective controls
Examine the controls, refurbish or renew as
necessary. Refer to component manufacturer's
documentation.
Defective piston seal
Dismantle the cylinder assembly, remove the
defective piston seal. Fit new seal
and reassemble.
Defective rod seal
Dismantle the cylinder assembly,
remove the defective rod seal. Fit new seal and
reassemble.
Defective housing seal
Dismantle the housing assembly, remove the
defective seal. Fit new seal and reassemble.
High valve torque or
valve seized
Consult the valve OEM documentation.
