Viking 855 Water Pump User Manual


 
SECTION TSM 685.2 ISSUE C PAGE 15 OF 16
TROUBLESHOOTING
Some of the following may help pinpoint the problem:
Pump does not pump:
Pump has lost its prime from air leak or low level in
tank.
Suction lift is too high.
Pump is rotating in the wrong direction.
The strainer may be clogged.
The bypass valve is open, the pressure relief valve is
set too low or the pressure relief valve poppet is stuck
open.
Improper end clearance.
The pump is worn out.
Are there any changes in liquid, system or operation that
would influence pump or coupling performance, e.g. new
liquid, additional lines or process changes?
Temperature changes either in the liquid or the
environment.
The magnetic coupling is decoupling. Changes in
application (temperature, pressure, viscosity, etc.) may
require torque beyond coupling capabilities.
Pump starts, then loses its prime:
The supply tank is empty.
Liquid is vaporizing in the suction line.
An air leak or air pocket in the suction line.
Pump is noisy:
The pump is being starved (viscous liquid cannot get
to pump fast enough). Increase the suction pipe size,
reduce its length or slow down the pump.
The pump is cavitating (liquid vaporizing in suction line).
Increase suction pipe size or reduce its length.
Check alignment.
The magnetic coupling has decoupled. Shut off and
restart.
Pump is not delivering up to capacity:
The pump is starving or cavitating - increase suction
pipe size or reduce length or reduce pump speed.
The strainer is partially clogged.
An air leak somewhere in suction line.
The pump may be running too slow. Is motor the correct
speed and wired up correctly ?
The pressure relief valve is set too low, stuck open or
has a damaged poppet or seat.
The bypass line around the pump is partially open.
The pump is worn out or there is too much end
clearance.
Pump takes too much power (stalls motor):
The liquid is more viscous than the unit is sized to
handle.
The system pressure relief valve is set too high.
The bushings have frozen up or the liquid has set up in
the pump.