Talk about the common failure problems of metal float flowmeter

1. Fibrillation.

(1) Mild chattering: generally caused by the undulation of gas potential flow. Gas damper can be installed to overcome.

(2) Moderate chattering: Generally due to unstable liquid conditions. For gas generally because of the medium operating pressure instability caused. Can choose to stabilize or reduce the pressure stabilization valve equipment to overcome or increase the flow meter gas damper to deal with.

(3) strong chattering: the key because the liquid for the pulse flow, unstable operating pressure or the selected flowmeter flow range and the actual work of the flow rate is too much difference. Panel type flowmeter supplier will try to deal with the pulse, lift the tank and modify the range of the flowmeter again.

2. The pointer stops to a certain position and does not move

(1) The main reason is that the float is stuck.

Generally because the instrument is used to open the gate valve too fast, so that the upper stop gear deformation, use as far as possible first slowly open the flowmeter inlet pump, and then slowly open the flowmeter outlet gate valve, until the flow position selected by the process. Equipment pipeline high-temperature steam sweep line, no use short takeover to replace the flowmeter lined with PTFE and thus make the PTFE parts deformation, so that the flowmeter can not work properly.

(2) pointer bearing rust

Oval gear flowmeter open cover wiring, indicating that the meter cover may not be properly installed in place, the screws are not torqued, so as not to exclude the installation of cable piping is not standardized, water backed up from the line pipe into the case, and then corrode the case parts.

3. Large data error

(1) Installation does not meet the requirements

(1) For the vertical installation of the instrument always keep vertical, the tilt angle is not more than 2 °.

(2) For the level installation meter always keep the level, the tilt angle is not more than 2 °.

3) The 100mm space around the meter must not have ferromagnetic objects.

4）Installation position should avoid gate valve size head mouth, pump outlet, process pipeline bend mouth, etc. Always maintain the first 5D after 250mm straight pipe section.

(2) The density of the liquid medium varies greatly is also a cause of large deviation. Because the instrument in the calibration before, are the media according to the density given by the customer to carry out calculations, calculated into the flow of the calibration situation drainage to carry out calibration, and therefore if the medium density change is large, will lead to a large deviation in the measurement.

Solution can be transformed after the media density to the formula, calculated into the deviation correction factor, and then the flow meter measured flow multiplied by the index for the real flow.

(3) gas medium because of the temperature and pressure suffered a large impact, it is proposed to choose the temperature and pressure compensation method to get the real flow.

(4) because of long-term use and pipeline vibration and other factors caused by the instrument sensing magnetic tile, pointer, counterweight, rotating magnetic tile and other moving parts loose, resulting in high quality vortex flowmeter deviation. Solution: You can first use the hand-push pointer method to verify. First of all, the pointer will be pushed in the RP position, see whether the export is 4mA, flow rate display

Whether 0%, and then successively in accordance with the scale to carry out verification. If you find that it does not match, you can adjust the position of the components. Generally, professional adjustment is required, otherwise the position will be lost and need to return to the manufacturer for calibration.