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Turbine Flowmeter Faults and Trouble-Shoot Methods

May 21, 2018

Turbine Flowmeter Faults and Trouble-Shoot Methods

 

For faults and trouble-shoot methods, please see Table as below:

Faults

Possible causes

Trouble-shoot methods

The liquid flows regularly,but the 

equipment fails to provide indication 

and increase of quantity

1)Broken supply  circuit or signal circuit 

or bad contact

1)Use a universal instrument to check the circuits and remove the breakdown point.

2)Failures or bad contacts of PCB and 

connectors

2) replacing PCB

3)Use a iron bar to move quickly under the detecting head, in the case of no signal output, check whether there is line cut and sealing-off at the soldered dot in the coil.

3)Breakdown of pre-amplifier

4)Voltage supplied for the pre-amplifier is

 too low

4)Rise source voltage up  to the

required level.

5)The impeller is clamped down and 

cannot move.

5)Remove the foreign matter and clean or replace the damaged parts,and  after  replacing  the  parts,  the transducer should be recalibrated.



1)The filter is blocked up and the pressure loss is growing bigger to reduce flow.

1)Remove foreign matters in the filter.

2)The  valve  plug  on  the pipeline is loosening, and the valve opening is reduced.

2)Repair or replace the valve.

3)The impeller is blocked up by impurity or

 foreign matters enter.The clearance between 

bearings,which bring about bigger resistance, 

thus reducingthe speed.

3)Clean the flow meter, if necessary,recalibrate it.

Flow indication is lowering 

gradually.When the fluid is not

flowing,but the indication is not

zero, and the

Indication value is not stable.

1) Bad shielding and groundingof the transmission line,Interference of outside,electromagnetic field.

1)Check the grounding and eliminate

the interference.

2)Pipeline vibration causes shake of impeller.

2)Fasten the pipeline or add supports

in front and back of the flow meter.

3)Leakage of globe valve

3)Repair or replace the valve.

4)Circuit or electronic components in the display Instrument are damaged and bring 

about interference.

4)Take “short-circuit” method or check

them  one by one to find out the

breakdown point.


 

The indicated flow is not in conformity with the actual flow.

1)The impeller as been corroded and the 

blades are deforming.

1) Repair the impeller or replace it and

then recalibrate the transducer.

2)Impurities have stopped the impeller from

 turning.

2)Remove such impurities.

3) The output signal of detecting coil is not 

normal.

3) Check the insulation resistance and

on resistance of the coil.

4) Fluid temperature is too high or too low, 

which results in big change of clearance between bearing and shaft.

 

5) Inadequate back pressure toresult in 

cavitation.

 

6) Fluid viscosity is becoming bigger as a 

result of temperature influence.

 

7) Reverse flow as a result of failure to

 install a clack valve.

Take tailor-made measures to remove

the fault.

8) Leakage of the bypass valve

8) Close the bypass valve, if necessary,

replace it.

9) Distortion of flow velocity distribution in

the upper streamof the transducer or a 

pulsating flow.

9) Try to find out the cause of such

distortion or pulsating flow and take

appropriate measures to eliminate such

influence.

10) Display instrument fault

10) Repair the display instrument

11)Incorrect connection of display instrument

11) Try to correct the connection

12) Wrong setting of display instrument

12) Try to correct the setting

13) The actual flow surpass the specified 

flow range.

13) Replace the flow meter with one of

proper diameter.

 

The user must contact us in case of failure of transducer during operation. In that case, please make detailed description of the instrument fault, operating conditions, measured fluid characters, model and serial number and other details of the faulted instrument.When it is necessary, please attach the schematic diagram of the installed pipeline as well as major technical parameter, for purpose of our better service for you.