Troubleshooting
Model 710 TruBlue Installation, Operation, and Maintenance Manual
68
Troubleshooting
Operation troubleshooting
Symptom
Cause
Remedy
The pump is not delivering
liquid.
The pump is not primed.
Re-prime the pump and check that the pump and
suction line are full of liquid.
The suction line is clogged.
Remove the obstructions.
The impeller is clogged.
Back-flush the pump in order to clean the impeller.
The shaft is rotating in the wrong direction.
Change the rotation. The rotation must match the
arrow on the bearing housing or pump casing.
The foot valve or suction pipe opening is not
submerged enough.
Consult an ITT representative for the proper sub-
mersion depth. Use a baffle in order to eliminate
vortices.
The suction lift is too high.
Shorten the suction pipe.
The pump is not producing
the rated flow or head.
The gasket or O-ring has an air leak.
Replace the gasket or O-ring.
The stuffing box has an air leak.
Replace or readjust the mechanical seal.
The impeller is partly clogged.
Back-flush the pump in order to clean the impeller.
The suction head is not sufficient.
Make sure that the suction-line shutoff valve is
fully open and that the line is unobstructed.
The impeller is worn or broken.
Inspect and replace the impeller if necessary.
The pump starts and then
stops pumping.
The pump is not primed.
Re-prime the pump and check that the pump and
suction line are full of liquid.
The suction line has air or vapor pockets.
Rearrange the piping in order to eliminate air
pockets.
The suction line has an air leak.
Repair the leak.
The bearings are running
hot.
The pump and driver are not aligned properly. Realign the pump and driver.
There is not sufficient lubrication.
Check the lubricant for suitability and level.
The lubrication was not cooled properly.
Check the cooling system.
The pump is noisy or vi-
brates.
The pump and driver are not aligned properly. Realign the pump and driver.
The impeller is partly clogged.
Back-flush the pump in order to clean the impeller.
The impeller or shaft is broken or bent.
Replace the impeller or shaft as necessary.
The foundation is not rigid.
Tighten the hold-down bolts of the pump and
motor. Make sure the baseplate is properly
grouted without voids or air pockets.
The bearings are worn.
Replace the bearings.
The suction or discharge piping is not an-
chored or properly supported.
Anchor the suction or discharge piping as neces-
sary according to recommendations in the Hy-
draulic Institute Standards Manual.
The pump is cavitating.
Locate and correct the system problem.
The impeller is excessively unbalanced.
Balance impeller to ISO balance grade G6.3.
The mechanical seal is leak-
ing excessively.
Tighten the gland nuts.
The mechanical seal parts are worn.
Replace the worn parts.
The mechanical seal is overheating.
Check the lubrication and cooling lines.
The motor requires exces-
sive power.
The discharge head has dropped below the
rated point and is pumping too much liquid.
Install a throttle valve. If this does not help, then
trim the impeller diameter. If this does not help,
then contact your ITT representative.
The liquid is heavier than expected.
Check the specific gravity and viscosity.
Rotating parts are rubbing against each other. Check the parts that are wearing for proper
clearances.
The impeller clearance is too tight.
Adjust the impeller clearance.
