The upper limit flow rate of a vortex flowmeter refers to the flow rate at full scale. The diameter of a steam flowmeter should be selected based on the flow range of the pipeline to be measured, the upper and lower limit flow rates of the selected instrument, rather than simply selecting based on the size of the connection.
The high flow rate of pipeline fluid is usually designed to be determined by the economic flow rate. Due to low flow rate selection, large pipe diameter, high investment, high flow rate, high transmission power, and increased operating costs.
The upper limit flow rate of most flow meters is close to or slightly higher than the economic flow rate of the pipeline. Therefore, the selected instrument has the same probability of having the same diameter as the pipe diameter and is easy to install. Even if their diameters are different, there is no difference between them. Usually, adjacent single size specifications can be selected. In this case, pipes of different diameters should be used for connection.
Some instrument flow limit values (or lower limit values) cannot be changed after being determined. Some instruments can be recalibrated by the user without the need for actual flow calibration. After designing a differential pressure gauge, the lower limit flow rate cannot be changed, but the upper limit flow rate can be adjusted by adjusting the range of the differential pressure transmitter.
What is the scope?
The so-called range is the ratio of the upper limit flow to the lower limit flow, and the larger the value, the wider the flow range. Linear instruments have a large range, while nonlinear instruments have a small range, which can meet energy-saving and commercial accounting cumulative flow measurement needs. However, in some cases, the tools required for business accounting have a wide range of requirements.
If a differential pressure gauge is used, adjustments cannot be made. However, in recent years, various differential pressure gauges have been broken and mainly used in differential pressure transmitters and microcomputer technology, but their prices have more than doubled.
In some manufacturers, the range of upper flow rates is very high and high flow rates are not used. The key is whether the lower limit flow rate is suitable for the measurement requirements. Usually, when a wide range is required, the lower limit flow rate is preferred to be as low as possible.