Limitorque LY Series - Torque Switch fails to stop actuator; Excessive current draw; Motor overload tripping; Valve is closed, but flow is not cut off

LMAIM1501 LY Installation and Maintenance for LY 1001, LY 2001 and LY 3001 7-11
Symptom Possible Cause Corrective Action
Reversing Starter failure Excessive cycling (too Review application to determine
frequent operation) number of starts per hour and
review with factory if more than
100 per hour.
Excessive current draw Valve running loads higher Inspect valve for possible causes
that expected of high running load. In particular,
check for excessive tightness of
valve packing and for proper
lubrication of valve. Consult
Flowserve for review of application.
Motor overload tripping Excessive current draw Inspect valve for possible causes
of high running load. In particular,
check for excessive tightness of
valve packing and for proper
lubrication of valve. Consult
Flowserve for review of application.
Incorrect overloads Verify proper overloads selected
for motor rating.
Excessive gear wear Excessive loads Verify actual loads are in
accordance with both start and
run capabilities of your actuator.
Inadequate lubrication Inspect quality and quantity of
lubrication in accordance with
Section 7.1, Lubrication.
Improper alignment Inspect worn gears for evidence
of uneven wear pattern.
Excessive torque Valve running loads higher Inspect valve for possible cause of
required to turn than expected high running loads. In particular,
handwheel check for excessive tightness of
valve packing, proper lubrication
of valve stem, bent or damaged
valve, tight Stem/Torque Nut
fit, worm, or damaged Stem Nut.
Unit is not properly aligned Take bolts off between the unit
with valve and the valve and check for
proper unit alignment.
Oil leaking from unit Infrequent operation of Institute periodic operation of
actuator resulting in grease unit into a maintenance program
separation to keep grease mixed. If not
possible, schedule more frequent
lubrication to ensure adequate
lubrication of gearbox.
Damaged or worn seals Replace seals.
Valve is closed, but Valve mechanical stops a. Do not set Torque Switch
flow is not cut off not set correctly higher than maximum setting
defined by Torque Limiter
CAUTION: Most quarter-turn valves are position-seated, not Plate. Inspect valve seat and
torque-seated. Applying additional torque to the hand- repair as required.
wheel and/or repeated electrical bumping at the full b. Check setting of Closed
closed position may damage the valve and/or the actuator. Mechanical Stop.
Flow Control Division
Limitorque Actuation Systems