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Hi, this is the Industrial Control Assistant. In the previous episode, we shared some basic knowledge about flowmeters; in this episode, we will learn about another type of flowmeter – the turbine flowmeter. Turbine flowmeters are used to measure the flow rate of liquids, gases, and vapors in pipes, such as carbon oxides, chemicals, water, cryogenic liquids, air, and industrial gases. Next, let’s take a detailed look at its application knowledge. High-precision turbine flowmeters can be used for the trading and transfer of hydrocarbons and natural gas. These turbine flowmeters usually include the functionality of a flow computer to correct for pressure, temperature, and fluid properties in order to achieve the accuracy required for the application. Care should be taken when using turbine flowmeters in unlubricated fluids, as premature wear of the flowmeter may cause it to become inaccurate and fail. Some turbine flowmeters have grease fittings for non-lubricating fluids. Furthermore, turbine flowmeters designed for specific applications (such as natural gas services) can generally operate within a limited temperature range (for example up to 60°C); therefore, operation at higher temperatures may damage the flowmeter. This type of flowmeter can be used for sanitary, relatively clean, and corrosive liquids with sizes up to about 24 inches. Smaller turbine flowmeters can be installed directly in pipes, but larger ones require a substantial concrete foundation and supports due to their size and weight. Pay due attention to the flow of corrosive liquids, as well as to the structural materials of all components that come into contact with liquids, such as valve bodies, rotors, bearings, and accessories. Turbine flowmeters are used in the water, oil, and chemical industries. Water applications include distribution systems within water areas and between water bodies. Petroleum applications include the trading and transfer of hydrocarbons. Other applications can be found in the food and beverage as well as chemical industries. A turbine flowmeter is a type of velocity meter that offers advantages such as high accuracy, good repeatability, simple structure, few moving parts, resistance to high pressures, wide measurement range, small size, light weight, low pressure loss, and easy maintenance. It is used to measure the volumetric flow rate and total volume of low-viscosity gases in closed pipelines. It has wide practical value in industries such as petroleum, chemicals, metallurgy, and urban gas pipelines. So what aspects should be considered when using turbine flowmeters? 1. Fluids with high impurity content, such as circulating cooling water, river water, wastewater, fuel, etc ； This is not entirely absolute; it depends on the amount of impurities present and the accuracy of the measurement. Turbine flowmeters are high-precision devices, but measuring such liquids can lead to increased measurement errors. It is possible to use flowmeters with lower precision or to filter the liquids first before using a turbine flowmeter for measurement ； 2. Locations with sudden changes in flow rate, such as boiler water supply systems and air hammer-equipped air supply systems ； Unstable flow rates are undesirable for turbine flowmeters, as they increase measurement errors; therefore, turbine flowmeters are not suitable for such conditions ； 3. When measuring liquids, if the pipeline pressure is low while the flow rate is high, the pressure on the downstream side of the instrument may approach the saturation vapor pressure, posing a risk of cavitation. For example, when liquid ammonia flows out freely from a high-level tank due to its potential energy, it is not appropriate to install such instruments at the discharge outlet ； 4. Areas with severe electromagnetic interference near welding machines, electric motors, contact relays, etc ； If it is necessary to use it, anti-magnetic measures must be taken ； 5. The length of the straight sections upstream and downstream is severely insufficient, such as in the engine room of a ship ； If the boiler’s automatic water supply system starts and stops the pump frequently, it causes stress on the impeller, leading to rapid damage of the sensors. That’s all for today’s content. Learn together with the little assistant every day*; whatever you want to know, the little assistant will do its best to search for answers or provide them. New updates will be available regularly, so feel free to stay tuned.