Orifice flowmeter is a high turndown differential pressure flow device composed of standard orifice plate and multi-parameter differential pressure transmitter (or differential pressure transmitter, temperature transmitter and pressure transmitter). It can measure gas, steam, liquid and induced flow, and is widely used in process control and measurement in the fields of petroleum, chemical industry, metallurgy, electric power, heating, and water supply. Throttle valve device, also known as differential pressure flow meter, consists of a primary detector (throttle valve) and a secondary device (differential pressure transmitter and flow display instrument). It is widely used in gases. Measure the flow of steam and liquid. The utility model has simple structure, convenient maintenance and stable performance.1. Differential pressure pipeline blockage and differential pressure pipeline dredging2. The differential pressure gauge is faulty, check the differential pressure gauge3. The indication value of the differential pressure transmitter is obviously deviated, and the indication value of the ruler should be checked.4. The throttle component is installed in the wrong direction, and the throttle component is reinstalled.5. The working condition parameters of the measured medium are inconsistent with the design parameters of the throttling device modified according to the relevant formula, and the pressure difference value should be recalculated if necessary.6. The length of the straight pipe section before and after the throttling device is not enough, the length of the straight pipe section should be adjusted.7. The inner diameter of the straight pipe section is too poor. Measure the inner diameter of the straight pipe section and recalculate the maximum flow rate.8. Throttle aperture is too bad, measure the throttle aperture, and recalculate the maximum flow.9. Deformation of the throttle element and replacement of the throttle element10. There are accessories on the throttle element, clean and replace the throttle element11. The sharp side of the orifice plate should flow toward the inlet end of the fluid, and the flared side should be the outlet end. If installed backwards, the display will be much smaller.Solution: Check the installation direction of the orifice plate, and install the orifice plate correctly.12. The entrance edge of the orifice plate is worn. If the orifice plate is used for a long time, especially in the case of solid particles and other debris, the geometry and size of the orifice plate will change. If the hole becomes larger or the edge of the hole becomes blunt, the measured pressure difference will become smaller and the flow rate will also decrease.Solution: Reprocess the orifice plate.13. Transmitter zero drift: If it is used for a long time, the zero point of the transmitter may drift. If it is negative drift, the displayed pressure difference will decrease and the displayed flow rate will also decrease.Solution: Correct the zero point of the transmitter.14. The length of the upstream and downstream straight pipes is not enough, the upstream and downstream straight pipes are not long, and the gas cannot develop fully, resulting in a large error in the measurement results. If the upstream straight pipe has more than one elbow, the measurement result is low.Solution: Reform the steam pipeline, and the length of the upstream and downstream straight pipe sections meets the specified requirements. Install a rectifier on the throttling device.15. Air leakage of the three-valve group of the differential pressure transmitter, if the high-pressure valve balance valve leaks in the three-valve group, it will cause the measured pressure difference to decrease and the measurement result will be low.Solution: If the high pressure valve of the three-valve group leaks, please tighten the valve and replace it if necessary. If the balance valve of the three-valve group leaks, tighten the valve and replace it if necessary.
Post time: 21-09-21