Fristam Pumps FPM 3531, English Translation Of The Original German Operating Manual, Page: 22 / 25

/ / FPM AND FSM SERIES / / /
20
Flow noise Operation contrary to design in overload or part-
load range. Adjust working point to design.
Flow loss in suction line too high. Increase nominal sizes; shorten connection lines;
prevent outgassing.
Cavitation. Check conditions for NPSH evaluation, contact
Fristam .
Vibrations Suction and discharge lines stressing pump
impermissibly. Support pipes so that pump is not stressed; possi-
bly install vibration dampers; keep water ham-
mers away from pump.
Unbalance of the magnetic coupling. Unbalance.
Motor power consumption too high Flow rate too high. Throttle discharge line or reduce speed with fre-
quency converter.
Impeller diameter too large. Trim impeller diameter; contact Fristam .
Viscosity and/or density of pumped product too
high. Contact Fristam .
Massive damage to the magnetic coupling, defa-
mation of the shaft. Disassembly, assessment, repair by Fristam .
Leakage at magnetic coupling Mechanical damage or wear of the magnetic cou-
pling Replace magnetic coupling including the elasto-
mers, replace material if necessary, contact
Fris-
tam
Contaminant shell defective Contact Fristam
Magnetic coupling running dry, suction height
excessive, temperature of conveyed media too
high Increase the pump's supply pressure, reduce suc-
tion height, contact
Fristam
Pumping medium temperature too high Contact Fristam
Unacceptable increase of the contamination
shell's temperature Abrasive particles in medium, viscosity of medium
too high Shut down pump, clean, and replace filter, if nec-
essary
Insufficient circulation, differential pressure too
low Contact Fristam
1
The "geodesic suction head" is the vertical distance between the suction-side liquid level and the center of the impeller.
Problem Possible cause Remedy
Table 10 Troubleshooting table