Pomac Pumps PLP - Page 64

User manual Pomac PLP Lobe pump
64 CE/PLP (1406) EN-12
Fault
Cause
Action
1
2
3
4
5
6
7
8
9
10
*
wrong direction of rotation
reverse direction of rotation
of drive
*
pump is not filled with liquid
vent suction line and rotor
case and prime rotor case
with liquid
*
*
*
*
insufficient NPSHA
Enlarge diameter of suction
line, or simplify suction line
and make it shorter, or
reduce speed and product
temperature
*
*
*
creation of vapour in suction
line
*
*
*
air entering the suction line
check the connections
*
*
*
*
gas in the suction line
vent suction line/pump
casing
*
*
*
insufficient static head
increase liquid level to
enlarge static head
*
*
*
*
product viscosity is too high
lower the speed / increase
the product temperature
*
product viscosity is too low
increase the speed / lower
the product temperature
*
*
*
*
*
product temperature is too
high
cool the product/pump
casing
*
*
product temperature is too
low
heat the product/rotor case
*
*
*
*
foreign particles in the
product
clean the system/ place a
filter at suction side
*
*
*
*
*
*
*
pressure at delivery side is
too high
check piping for
obstructions / simplify the
pressure line
*
*
*
*
*
rotor case distorted by
piping
check alignment / support
the piping
*
*
speed to high
lower the speed
*
speed too low
increase the speed
*
*
*
*
*
*
insufficient flushing
increase flushing pressure /
- capacity
*
*
*
*
*
*
*
worn-out bearings/gears
replace the worn-out parts
*
safety valve is opened
Check if delivery valve is
opened/check piping for
obstructions/check piping
system for pressure loss