Oval Gear Flow Meter is widely used in industrial and agricultural production, national defense construction, scientific research, foreign trade and people's life. In the production of petroleum industry, flow measurement runs through the whole process from oil exploitation, transportation, refining, metallurgy and processing to trade sales. Any link can not be separated from flow measurement, otherwise the normal production and trade exchanges of the oil industry can not be guaranteed. In chemical industry, inaccurate flow measurement will cause imbalance of chemical composition distribution ratio, unable to guarantee product quality, and even production safety accidents will occur. In the electric power industry production, the measurement and regulation of the flow rate of liquid, gas, steam and other media occupy an important position. The accuracy of flow measurement is not only of great economic significance to ensure that the power plant operates under the optimal parameters, but also with the development of high temperature, high pressure and large capacity units, flow measurement has become an important link to ensure the safe operation of power plants. If the instantaneous feed water flow of large capacity boiler is interrupted or reduced, serious dry boiler or tube burst accident may be caused. This requires the flow measurement device not only to measure accurately, but also to send out alarm signal in time. In the production of iron and steel industry, the flow measurement of circulating water and oxygen (or air) is one of the important parameters to ensure the quality of products. In light industry, food, textile and other industries, it is also inseparable from the Oval Gear Flow Meter.