Common faults and treatment of Liquid Turbine Flow meter

Common faults and treatment of Liquid Turbine Flow meter

Fault phenomenon	Reason	Treatment measures
There is no display when the fluid flows normally.	1. The power line, fuse, etc. is broken or in bad contact. 2. Poor internal contact in display instrument. 3. The coil is broken 4. The sensor’s flow channel is faulty.	1. Check with the ohmmeter. 2. Adopt the “back up board” method to check. 3. Check whether coil is broken or solder spot is fall off. 4. Remove foreign body from the sensor and clean or replace damaged parts.
Flow rate display drops gradually	1. Filter blockage 2. The valve spool on the sensor’s pipe section becomes loosen and the valve opening decreases. 3. Sensor impeller is blocked by debris or foreign bodies enter the bearing clearance, resistance increases.	1. Clean the filter. 2. Judge whether the valve spool is loosen through the valve handwheel adjustment is effective 3. Remove the sensor to eliminate the debris and recalibrate if necessary.
The fluid is not flowing, but the flow rate display is not zero	1. Transmission line’s shielding grounding is not good. 2. The impeller shakes accompany with the pipe vibration. 3. Stop valve is not closed tightly. 4. Display unit’s internal circuit board or electronic components damage.	1. Check whether shielding wire is good grounding. 2. Reinforce the pipeline, or install brackets at inlet and outlet of the sensor to prevent vibration. 3. Repair or replace the stop valve. 4. Take the “short-circuit method” or check item by item to justify the interference source and find out the fault point.
The difference between the display value and the empirical value is significant	1. The flow channel of the sensor is faulty. 2. Back pressure of the sensor is insufficient, occur cavitation, which affects impeller rotation. 3. Reason of flowing in pipeline. 4. Internal failure of display unit. 5. The permanent magnet elements in the detector loses the magnetization. 6. The actual flow which pass the sensor exceeds the specified range.	1-4. Find out the cause of the failure and take countermeasures. 5. Replace the elements which loses the magnetization. 6. Select the appropriate sensor.