5.7 Troubleshooting
1 No flow
2 Under capacity
3 Irregular discharge
4 Low discharge pressure
5 Pump will not prime
6 Prime lost after starting
7 Pump stalls when starting
8 Pump overheat
9 Motor overheats
10 Excessive power absorbed
11 Noise and vibrations
12 Pump element wear
13 Syphoning
14 Seizure
15 Mechanical seal leakage
16 Mechanical seal leakage
Problem
Probable Causes
Solutions
1 2 3 4 5 6 7 8 9 10
11
12
13
14
15
16
x
x
Incorrect direction of
rotation
Reverse motor
x
Pump not primed
Expel gas from suction line and
pumping chamber and introduce fluid
x x
x
x
x
Insulficient NPSH available
Increase suction line diameter
Increase suction head
Simplify suction line configuration and
reduce length
Reduce pump speed
x
x
x
x
Fluid vaporising in
suction line
Increase suction line diameter
Increase suction head
Simplify suction line configuration and
reduce length
Reduce pump speed
x
x
x x
x
Air entering suction line
Remake pipework joints
x
x
x
Strainer or filter blocked
Service fittings
x
x x x
x
x
x
Fluid viscosity above
rated figure
Increase fluid temperature
Descrease pump speed
Check seal face viscosity limitations
x
x
Fluid viscosity below
rated figure
Decrease fluid temperature
Increase pump speed
x
x
x
x
x
Fluid temp. above rated
figure
Cool the pump casing
Reduce fluid temperature
Check seal face and elastomer temp.
limitations
x
x x
Fluid temp. below rated
figure
Heat the pump casing
Increase fluid temperature
x
x
Unexpected solids in fluid
Clean the system
Fit strainer to suction line
If solids cannot be eliminated
consider fitting double mechanical seals
200002348-1-EN-GB
59
Maintenance 5
EN
Summary of Contents for DuraCirc Range
Page 4: ......
