ProMinent DULCO flex DFCa Operating Instructions Manual page 34

Maintenance, repair, malfunctions, disposal and spare parts
Problem
Vibrations on pumps and pipelines The pipes are not correctly fas‐
Short operational lifetime of the
hoses
Pump hose pulled into the pump
housing
The pump does not start up
34
Possible cause
Air introduction in the suction con‐
nections
tened
Pump speed too high
Insufficient nominal width of the
pipes
Pump base plate loose
Pulsation dampers insufficient or
missing
Chemical exposure
High pump speed
High conveying temperature
High operating pressure
Pump cavitations
High inlet pressure (> 3 bar)
Pump hose filled with deposits
Holder (pressure flange) insuffi‐
ciently tightened
Insufficient motor performance
Insufficient output from frequency
converter
Blockage in the pump
Solution
Check connections and accesso‐
ries for air tightness
Fasten pipes correctly (e.g. wall
brackets)
Reduce pump speed
Increase nominal width
Fasten base plate
Install pulsation dampers on suc‐
tion and / or discharge side.
Check the compatibility of the
hose with the liquid being con‐
veyed, the cleaning fluid and the
lubricant
Reduce pump speed
Reduce product temperature
Reduce operating pressure
Check the suction conditions
Reduce inlet pressure
Clean or replace the pump hose
Re-tighten holder (pressure
flange)
Check motor and replace if neces‐
sary
The frequency converter must
match the motor
Check voltage. Start occurs at
minimum 10 Hz
Check if the suction or discharge
side is blocked. Rectify blockage