Common faults and solutions of metal tube rotary flow meters
 |
 |
The metal tube rotary flowmeter has a simple structure, reliable operation, high accuracy, and a wide range of applications. The flowmeter has various types such as on-site indication, electric remote transmission, limit switch alarm, corrosion resistance, jacket type, damping type, and explosion-proof. Widely used in petroleum, chemical, power generation, pharmaceuticals, food, water treatment, etc. In the process of flow measurement under complex, harsh environmental conditions, and various medium conditions.
In order to ensure the normal operation of the metal tube float flowmeter and achieve a certain measurement accuracy, the following points should be noted when installing the flow meter:
1. The metal tube float flowmeter must be installed vertically on a vibration free pipeline. The fluid flows through the flowmeter from bottom to top, and the verticality is better than 2 °. When installed horizontally, the horizontal angle is better than 2 °;
2. In order to facilitate maintenance and replacement of flow meters, cleaning of measurement pipelines, metal tube float flow meters installed on process pipelines should be equipped with bypass pipelines and bypass valves;
3. The inlet of the metal tube float flowmeter should have a straight pipe section with a length of more than 5 times the pipe diameter, and the outlet should have a 250mm straight pipe section;
4. If the medium contains ferromagnetic substances, a magnetic filter should be installed; If the medium contains solid impurities, it should be considered to install a filter between the valve and the straight pipe section;
5. When used for gas measurement, it should be ensured that the pipeline pressure is not less than 5 times the pressure loss of the flowmeter to ensure stable operation of the float;
6. In order to avoid deformation of the flow meter caused by pipelines, the flange of the process pipeline must be coaxial and parallel to the flange of the flow meter. The pipeline support should be used to avoid pipeline vibration and reduce the axial load of the flow meter. The control valve in the measurement system should be installed downstream of the flow meter:
7. When measuring gas, if the gas is directly discharged into the atmosphere at the outlet of the flowmeter, a valve should be installed at the outlet of the instrument, otherwise a pressure drop will occur at the float, causing data distortion.
8. When installing instruments with PTFE lining, do not tighten the flange nuts asymmetrically to avoid deformation of the PTFE lining;
9. Instruments with LCD displays should avoid direct sunlight on the display as much as possible to avoid reducing the lifespan of the LCD; Instruments powered by lithium batteries should avoid direct sunlight and high temperature environments (≥ 65 ℃) as much as possible to avoid reducing the capacity and lifespan of lithium batteries.
10. Used for measuring the flow rate of small caliber and low flow rate media; Reliable operation, low maintenance, and long service life; Low requirements for straight pipe sections; A wider flow ratio of 10:1; Dual row large LCD display, optional on-site instantaneous/cumulative flow display, with backlight single axis sensitive indication; Non contact magnetic coupling transmission.
Common problems and solutions for metal tube float flow meters
Metal tube float flowmeter without on-site display:
1. Check if the wiring is correct.
2. Check if the power supply is correct.
3. Reinstall the LCD module and check for loose contact.
4. For the multi wire power supply method, check whether terminals 12 and 13 are connected to an ammeter or have a short circuit.
Metal tube float flowmeter alarm incorrect:
1. Check that the deviation setting d of the steam flow meter cannot be too large.
Is the logic function correct in the FUN function. HA-A represents upper limit positive logic. LA-A represents lower bound positive logic.
3. Check the alarm value setting size in SU.
If the LCD barcode indicates correctly and there is no output action, check whether the external power supply and the negative of the external power supply are connected to the negative of the instrument power supply.
5. Circuit board failure, replace the circuit board.
