M Pumps V MODULAR Series User Manual page 17

Insufficient inlet pressure, with the
generation of cavitation and loss of
.
efficiency
Wear ring, wear pump casing or impeller.
The temperature of the liquid is close to
boiling point
NO FLOW
Causes
The pump is defused
Suction line blocked
The magnetic coupling decouples
The motor stopped
EXCESSIVE FLOW
Causes
The head required is lower than that
provided by the pump
OVERHEATING OR MOTOR STOP
Excessive pumped liquid density
Increase the static height at the suction
Check that the intake is not blocked or are no bottlenecks.
Reduce the liquid temperature. Increase the diameter of the
intake pipes.
Reduce the length of inlet pipes. Open completely the inlet
valve. Check the viscosity of the liquid; refer to "technical
data" section of this manual, increase the temperature of the
liquid if necessary.
Check the condition of rotating ring wear and collar. Replace
if worn; refer to Chapter 10 of this manual
Reduce the liquid temperature
Remedies / actions
Re-prime the pump. Refer to section 3.5.1 of this manual.
Check for air leaks in the suction line
Ensure that there are no blind pipes, obstructed or valves
closed
Reduce the flow: partially close the discharge valve. Reduce
the density of the liquid, if possible. Reduce the prevalence
of the pump (check in advance with your distributor
M PUMPS
inside in case this does not happen. Reduce the engine
power installed (check in advance with your distributor
M PUMPS
Check the power of the motor. Check the status of the
motor.
Remedies / actions
Reduce the speed of rotation, if possible; reduce the impeller
diameter; partially close the discharge valve.
Reduce the flow by closing the valve outlet partially
Doc. ISM0023 Instruction Manual of series V MODULAR – Rev.02
.
). Make sure the pump turns freely; inspect the
). Adopt star-delta starting
.
.
.
.
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