Turbine flowmeter common faults and solutions

- Nov 24, 2017 -

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one,

1. Symptom: no flow of normal fluid flow, the total number of words does not increase the counter

Possible causes

a Check the power cord, fuses, function selection switches and signal lines with or without broken open circuit

b check the display internal printing plate, contacts and other non-contact bad

c Check the detection coil

d Check the sensor internal fault, the above 1-3 items are confirmed normal inspection or troubleshooting, but there are still symptoms, indicating that the fault within the sensor flow channel can check whether the impeller touch the sensor wall, with or without foreign body stuck, the shaft and Whether the bearing stuck or broken debris phenomenon

3. Solution:

a ohms to troubleshoot the problem

b printing plate failure inspection can be replaced by "spare" method, replace the fault plate and then make a detailed inspection

c do a good job of testing the coil position mark on the sensor body, unscrew the test head, with iron quickly move under the test head, if the counter does not increase the number of words, you should check the coil without breaking and solder joint desoldering

d to remove foreign matter and cleaning or replacement of damaged parts, air blow or hand impeller impeller should be restored, no friction sound, replacement of bearings and other parts should be re-calibrated to obtain a new instrument coefficient

two,

1. Symptom: no reduction of traffic operations, but traffic shows gradually declined

Possible causes

a filter is clogged, if the filter pressure increases, indicating debris has been blocked

b flow sensor spool valve spool loosening occurs, the valve opening automatically reduced

c Sensor impeller obstructed by debris or bearing clearance into the foreign body, increased resistance and deceleration slow down

3. Solution:

a Remove the filter

b from the valve handle to adjust the effective judgments, confirmed after repair or replacement

c Remove the sensor and clear it again if necessary

three,

1. Symptom: The fluid does not flow, the flow display is not zero, or display the value of instability

Possible causes

a transmission line shielding poor grounding, external interference signal mixed into the display input

b pipe vibration, impeller jitter, resulting in a false signal

c closing valve is not strict due to leakage, in fact, the instrument shows the amount of leakage

d display instrument internal circuit board or deterioration of electronic components, resulting in interference

Solution

a Check the shield to indicate that the terminal of the instrument is well grounded

b Reinforce pipelines or add brackets on the front and back of the sensor to prevent vibration

c Repair or replace valve

d to take "short circuit" or item by item one by one check to determine the source of interference, identify the point of failure

1. Symptom: Display instrument value and the experience of significant differences

Possible causes

a sensor flow channel internal fault If subject to fluid corrosion, serious wear and tear, debris impede the impeller rotation disorder, the instrument factor changes blade corrosion or impact, the top deformation, affecting the normal cutting magnetic lines, the detection coil output signal failure, the instrument coefficient changes: fluid The temperature is too high or too low, the shaft and bearing expansion or contraction, the gap caused by excessive changes in impeller rotation disorders, the instrument coefficient changes.

b lack of back pressure sensor, cavitation, affecting impeller rotation

c pipe flow reasons, such as not installed check valve reverse flow bypass valve is not closed, there is leakage upstream of the larger flow velocity distribution distortion: (as a result of the upstream valve is not fully open) or the occurrence of pulsating fluid by Temperature-induced viscosity changes and so on

d Display internal fault

e detector permanent magnet material components aging loss of magnetism, reduced to a certain extent, will affect the measured value

f The actual flow through the sensor has exceeded the sensor's specified flow range

Solution

a-d to find out the cause of the malfunction, for specific reasons to find countermeasures

e Replace the demagnetizing element

f Change the appropriate sensor


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