Variable Area Flow Meters (Rotameters)

The Variable Area Flowmeter is an instrument for measuring the flow of liquids and gases in pipelines. It includes a vertical tube through which the fluid flows whose diameter increases from the bottom to the top and a float which can move vertically in the tube. As the flow increases this float moves to a higher position until its resistance to the fluid flow is balanced by the float’s buoyed weight in the fluid, a value which is constant and independent of the flowrate. The position of the float is a measure of the flowrate. The flowrate values can be read on a scale.

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  • Basic liquid (including water) or gas flow measurement
  • Rotating equipment flow measurement
  • Process analyzers
  • High-pressure flow on offshore oil platforms
  • Chemical injection
  • Purge liquid or gas metering