SPP id: Version 14 > / 120601 / Replaces 110901 / en /
N31572
/ 2 / Page 10 (12)
Series
2.15
INSTRUCTIONS
June 2012
Page
ISO
G
COPYRIGHT © SULZER PUMPS FINLAND OY
ORIGINAL INSTRUCTION
USER'S MANUAL – AHLSTAR
Operation
6 Trouble-shooting - operation
During the start-up period, problems are mostly caused by pump selection mistakes, poor process design,
operational mistakes or foreign objects in the process.
During the long-term operation of a pump unit, problems are mostly caused by random failures, process changes or
corrosion and wear.
Problems can normally be traced to either poor maintenance or exceeding the limitations for the intended use of the
pump.
The following problem tracing analysis includes the most common malfunctions and their possible causes. If the
pump does not function properly, it is important to trace the actual reasons, so that the repairs and required
modifications can be done without delay. Table 3 - Table 10.
Table 3, Symptom: Pump not delivering liquid
Probable cause:
Remedy:
Wrong direction of rotation
Change the direction of rotation acc. to the arrow sign on the
bearing unit
Pump not adequately primed or
a
vapor lock in the suction
pipe
Reprime the pump and suction piping
Flushing liquid is not on (liquid ring pumps (-LM, -S))
Open the flushing liquid valve
Difference between inlet pressure and vapor pressure too
small
Check the suction piping arrangements
Air leakage in suction opening, suction piping or shaft seal
Check the suction piping. Readjust the shaft seal
Suction piping, suction valve or impeller clogged
Check the suction piping and the pump for any obstructions
Rotational speed too low
Check the speed requirements/limitations
Flow resistance of the piping higher than the head generated
by the pump
Check resistancies and reduce losses
Unexpected air/gas content in the pumped liquid
Consult manufacturer for further instructions
Suction tank level low
Check the required inlet/suction head
Table 4, Symptom: Insufficient head
Probable cause:
Remedy:
Unexpected air/gas content in the pumped liquid
Consult manufacturer for further instructions
Unexpected viscosity of the pumped liquid
Consult manufacturer for further instructions
Suction piping, suction valve or impeller clogged
Check the suction piping and the pump for any obstructions
Rotational speed too low
Check the speed requirements/limitations
Wrong direction of rotation
Change the direction of rotation acc. to the arrow sign on the
bearing unit
Flow resistance of the piping higher than the head generated
by the pump
Check resistancies and reduce losses
Pressure containing pump parts worn/damaged/clogged
Check the pump and replace defective parts, if necessary
Suction tank level low
Check the required inlet/suction head
Table 5, Symptom: Insufficient (or irregular) flow
Probable cause:
Remedy:
Vapor lock in the suction pipe
Reprime the pump and suction piping
Suction head too high
Check that the suction valve is fully open and that the suction
line is unobstructed
Difference between inlet pressure and vapor pressure too
small
Check the suction piping arrangements
Air leakage in suction opening, suction piping or shaft seal
Check the suction piping and readjust the shaft seal
Unexpected air/gas content in the pumped liquid
Consult manufacturer for further instructions
Unexpected viscosity of the pumped liquid
Consult manufacturer for further instructions