8 malfunctions, 8malfunctions – Richter MNK Series User Manual
Page 22

Series MNK 200-150-315
Page
22
9230-053-en
Revision 12
TM 8195
Edition 03/2011
8
Malfunctions
Faults may result from inadmissible modes of 
operation. Such improper operation – even 
brief ones – may cause serious damage to the 
unit. 
In connection with explosion protection, potential 
sources of ignition (overheating, electrostatic and 
induced charges, mechanical and electric sparks) can 
result from these inadmissible modes of operation; 
their occurrence can only be prevented by adhering to 
the intended use. 
See also Section 6.5.
Should there be any uncertainty about the remedy to 
be applied, please inquire at the in-house pump office 
or at the pump manufacturer's. 
No delivery :
Is the pump filled and vented? 
Is the suction line open, vented, cleaned and 
correctly laid? 
Is the discharge line open, vented, cleaned and 
correctly laid? 
Is the geodetic head too high? 
Is air being drawn in? 
Has the magnetic drive stopped? 
Flow rate too low :
Have the pump, suction line and discharge line 
been completely vented, filled and cleaned? 
Have any strainers installed been cleaned? 
Are all shut-off devices open? 
Is the geodetic head too high? 
Is the NPSHA too low or the NPSHR too high? 
Are the pipe resistances too high? 
Is the viscosity too high? 
Is the direction of rotation correct? 
Is the speed too low or the impeller diameter too 
small? 
Are pump parts worn? 
Gas in the medium? 
Flow rate too high :
Is the geodetic head too low? 
Are the pipe or nozzle resistances too low? 
Is the pump speed too low or the impeller diameter 
too large? 
Delivery pressure too high :
Is the speed too high or the impeller diameter too 
large? 
Is the density too high? 
Motor consumes too much electricity :
Is the flow rate, density or viscosity too high? 
Is the speed too high or the impeller diameter too 
large? 
Is the coupling correctly aligned? 
Can the pump shaft be turned properly? 
Pump does not run smoothly or creates 
noises : 
Is the coupling well aligned? 
Are the coupling elements worn? 
Are the rolling bearings damaged? 
Are parts of the hydraulics damaged? 
Is the flow rate too low or too high? 
Is the impeller balanced? 
Is the pump twisted? 
Is there foreign matter in the pump? 
Temperature of the rolling bearings is too 
high : 
How high is the actual temperature measured? 
How high may it be acc. to the operating manual? 
Is the running-in phase already over? 
Deficient lubricant? 
Overaging / wear? 
Leak from the pump :
Are all screws tightened to the correct tightening 
torque? 
Were the sealing surfaces assembled in a clean 
state? 
Have approved gaskets been installed? 
