The upper limit flow is also referred to as the full flow or maximum flow of the flow meter. When we choose the diameter of the flowmeter, it should be configured according to the flow range used by the pipeline to be tested and the upper and lower flow rates of the selected flowmeter. It cannot be simply used according to the pipeline diameter.
In general, the maximum flow rate for designing a pipe fluid is determined by the economic flow rate. If the choice is too low, the pipe diameter is thick, the investment will be large; if it is too high, the transmission power is large, and the running cost is increased. For example, a low-viscosity liquid such as water has an economical flow rate of 1.5 to 3 m/s, and a high-viscosity liquid of 0.2 to 1 m/s. The flow rate of most flow rate upper flow rates is close to or higher than the economical flow rate of the pipeline. Therefore, when the flowmeter is selected, its diameter is the same as that of the pipeline, and the installation is convenient. If they are different, they will not be too different. Generally, the specifications of the upper and lower ones can be connected by different diameter pipes.