Operating manual for centrifugal pumps AT - TB… - MC… - TC… - TMA
35
Fig. 34
d2.1 Threaded connection – Inlet
cooling/heating liquid to mechanical
seal housing
d2.2 Threaded connection - Outlet
cooling/heating liquid to mechanical
seal housing
d4.1 Threaded connection – Inlet
cooling/heating liquid pump
jacketed casing
d4.2 Threaded connection - Outlet
cooling/heating liquid pump
jacketed casing
16 - TROUBLE SHOOTING CHART - PROBLEMS, CAUSES AND SOLUTIONS
Consult the following table when problems are experienced, if solutions are not found in this chart (tab. 5) or should there
be any doubts, do not hesitate to contact POMPETRAVAINI or your local representative.
Tab. 5 -
LIST OF PROBLEMS
PROBLEM
LIST OF POSSIBLE CAUSES
Lack of, or no flow and/or pressure
1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 17 - 25 - 40
Excessive flow and/or pressure
15 - 16 - 17 - 18
High power consumption
10 - 15 - 16 - 18 - 19 - 20 - 21 - 22 - 23
Excessive vibration and noise
8 - 18 - 19 - 20 - 23 - 24 - 25 - 26 - 27 - 28 - 36 - 37 - 40
Bearing overheating
19 - 20 - 28 - 29 - 30 - 36 - 38 - 39 - 42
Sealing malfunction
28 - 31 - 32 - 33 - 34 - 35 - 40 - 41
CAUSES
SOLUTIONS
1
Pump is not primed
Repeat the priming procedure
2
Rotational speed is not adequate
Increase the motor speed in relation to the working conditions -
Replace impeller with one having larger diameter.
3
Installation requires higher pressure
than expected
Increase operating speed, if possible, (see point 2) or replace
impeller with one of larger diameter - Change the pump or
increase the number of stages in case of multistage pumps -
Reduce the system pressure
4
Wrong direction of rotation
Change the motor direction of rotation
5
There are air pockets in the suction line
Modify the layout of suction piping
6
Air enters the suction line
Check the piping sealing areas
7
The pumped liquid is emulsified with air
Install a reservoir or tank before the pump to de-aerate the liquid
8
The suction lift or/and suction pressure
is more than anticipated and therefore
the pump cavitates
Reset the suction lift to the original value - Increase the piping
diameter - Check the suction piping, the foot valve or non return
valve, the filter - Open completely the isolating valve in the
suction piping - Decrease the friction losses
9
The wear ring and/or impeller neck
and/or the impeller and/or the diffusers
are worn out or damaged
Overhaul the pump replacing and/or repairing the damaged
components
10
Viscosity, density, or specific weight of
liquid have higher values than expected
Re-establish the characteristics of the liquid as originally
expected (if necessary contact POMPETRAVAINI)
11
Suction piping is not sufficiently
submersed in the liquid, creating vortex
Increase the depth of piping or foot valve in the liquid
12
Impeller is plugged with scale deposit
and/or foreign materials
Take out the impeller, clean it, free the vanes and cavities of any
materials - Soften the pumped liquid
13 There is entrained air in the system
Adjust the packed stuffing box or repair/replace the mechanical
seal
14 Piping is plugged
Clean piping and valves - clean the filters
15 Velocity is too high
If possible, decrease the pump rotational speed
16
The required pressure of system is lower
than anticipated
Adjust the flow regulating valve in discharge piping - Decrease
the impeller diameter (contact POMPETRAVAINI) - Decrease
the number of stages in case of multistage pumps
17 Pump is not suitable for the application Contact
POMPETRAVAINI
d2.2
d4.1
d2.1
d4.1
d4.2
