The flowrate of gases and liquids can be determined simply, yet relatively accurately with variable area flowmeters. The measuring medium flows upward through a vertical conical tube whose diameter increases in the upward direction. The upward flowing fluid
lifts a float located in the tube to a height so that the annulus has an area which results
in an equilibrium of the forces acting on the float.
Comparing the flowmeters with the product and installation cost, simplicity of design, piping requirements, Variable area flowmeters are the most effective solution for almost all applications involving the measurement of industrial process liquids, gases or steam. Another outstanding advantage due to its mechanical design is that it does not require external power supply.
First analyzing the flow and its properties and decide what type of variable are flow meter will be, then we choose a float for your variable area flowmeter.
Advantages:
– Inexpensive
– No external power supply required for local indication
– Suitable for liquids, gases and steam
– No inlet and outlet sections required
– Simple meter design, therefore easy to install and maintain
– Indication also with opaque liquids
– Metal cone meter with transmitter
– Metal cone meter can be sterilized, CIP tested
Limitations:
– Vertical mounting position
– Constant pressure drop
– Affected by density, temperature and viscosity changes
– Solids damage metering edge, otherwise slight contamination allowed
– Affected by pulsation and vibration
– Expensive when exotic materials are required
The metal cone variable area is the first choice for chemical plants and oil and gas rigs.
The armoured variable area purgemeter is designed for low gas and liquid flows.
Glass tube variable area flowmeter for a high degree of reproductivity.
Optimum flexibility with a mininmum number of components.
These are also designed specially for marine, lubricant monitoring and seal applications.