22
Ek-2/TL-KLT-01-01 / Rev 0
APPENDIX D
TROUBLESHOOTING GUIDE
In diagnosing pump and "system" troubles, the following information is essential:
1. Pump model and serial number
2. Electric motor; hp and RPM
3. Product specific gravity
4. Product temperature
5. Pressure at pump’s suction port
6. Pressure at pump’s discharge port
7. Pressure in the storage tank
8. Pressure in the tank being filled
9. Size and length of the discharge pipe and hose
filter screen. The suction pipe might be too small
Low Capacity
Problem Cause
What
To
Do
Pump speed too low
Wrong electric motor
Check the RPM of the electric motor.
High differential pressure
Remove the restrictions in the discharge piping /
hose, or increase their sizes.
Vapor lock
Regenerative turbine pumps "vapor- lock" when
reaching their maximum differential pressure
capability. See above for high differential pressure.
By-Pass valve stuck open or set
too low
Readjust, repair or replace the by-pass valve
Clogged strainer
Clean strainer screen.
Worn impeller
Replace the impeller.
Suction pipe too small or
restricted
Indicated by pump’s inlet pressure dropping when
the pump is started. Remove restrictions and/or
increase pipe size.
Pump runs but
no flow
Valve closed
Check valves and make sure they are in the
open position.
Excess flow valve slugged or
closed
Stop pump until the excess flow valve opens. If the
problem continues, install a new or larger capacity
excess flow valve.
Wrong rotation
Check the rotation of the electric motor and
change the rotation.
Suction pipe too small or
restricted
Indicated by pump’s inlet pressure dropping when
the pump is started. Remove restrictions and/or
increase pipe size.
Pump will not
turn – locked
Foreign matter in the pump
Clean out the pump – inspect the strainer screen.
Bearing seized
Replace the pump’s bear
Moisture in the pump
Thaw and break loose carefully. Check with the
product supplier if the product contains water.
Properly remove the moisture from the product.
Pump will not
build pressure
Poor suction conditions
Check the storage tank excess flow valve – Clean
or restricted. Remove restrictions and/or increase
pipe size.
By-Pass valve set too low
Set the valve for higher pressure
Too much impeller’s clearance
Do a Performance Test on the pump
Low Capacity