MIS_100
Data di emissione 11/06/2015
Pag.24 di 32
Malfunction
Check possible causes
Possible solutions
Vibration / Noise
-
pump
-
excessive forces and moments acting on delivery and/or
pump suction connections
-
not sufficiently rigid base plate or in resonance with the
pump in the frequencies range from 40 to 70 Hz
-
pump working with insufficient flow rate
-
liquid pumped with values different from the design
parameters: viscosity, vapour pressure at working
temperature, air or gas content,…
-
damaged or clogged impeller
-
incorrect installation (pipes, curves, valves,..)
-
check the correct assembly of
pump/plant connections and correct
pipes bracket and support (ref. to 9.5)
-
increase the base plate rigidity and/or
modify the pump/base plate
mechanical constraint (ref. to 9.4)
-
adjust the flow rate with the by-pass
valve
-
check the correct installation (ref. to 9):
increase the hydrostatic head on the
pump suction, check air-tight of
suction pipe,…
consult the pump and/or plant
manufacturer
-
clean or replace the impeller
-
check the plant (ref. to 9)
Liquid leaks
-
pump
-
gaskets (flats or O-rings) affected by chemicals
-
incorrect assembly of fittings, bolts, gaskets,…
-
excessively abrasive liquid: wear of housings and grooves,
pump casings and cover,...
-
replace damaged parts, check
chemical compatibility
-
review assembly
-
replace damaged parts and check the
possibility to decrease wear; materials,
plant modifications,…
consult the manufacturer
-
improve inspections and maintenance
and increase frequency of intervention
-
mechanical
seal
-
running dry or precarious priming (damage to mechanical
seal faces, plastics melting, thermal shock,…)
-
sticking of seal faces due to crystals, calcareous deposits,
encrustation, evaporation of liquid,…(shearing of bellow,
plastics melting,..)
-
damaged spring, spring and/or bellow convolutions
clogged by foreign matter
-
excessive forces and moments, acting to the pump
delivery or suction connections, misalign the mechanical
seal
-
if the motor was replaced, it is not in accordance with point
15 page 18
-
replace damaged parts (mechanical
seal, pum
p casing and/or shaft,…)
check the tank minimum level, the air-
tight of suction pipe, improve the pump
working standards (see the Use
Manual)
-
replace damaged parts (mechanical
seal, pump casing and/or shaft,…),
ensure the pump casing is completely
filled at all times. Avoid long stops and
that over-saturated solutions cool
down,…
-
replace damaged parts, clean clogged
parts
-
check the correct assembly of
pump/plant connections and the
correct pipes bracket and support (ref.
to 9.5)
-
replace the motor correctly
Recurrent
malfunctioning,
too frequent
maintenance
interventions
-
motor
-
bearings
bracket
-
pump
-
mechanical
seal
-
ancillary
equipment
-
look for causes according to the inspection and
maintenance records
-
improve inspections, preventive
maintenance, and operators
’ training;
consult the pump manufacturer
Read the Pump Use Installation and Maintenance Manual carefully.
