BES Flowmeters supplies variable area flow meters (also known as rotameters) for industrial liquid and gas measurement. Simple, robust and reliable with no power required, variable area flow meters are one of the most widely used flow meter technologies in Australian industry. BES stocks the BES 7200 Series, MPB Industries range and Kobold variable area meters.
How Variable Area Flow Meters Work
A variable area flow meter consists of a vertically mounted tapered tube (glass or metal) containing a float. As fluid flows upward through the tube, the float rises until the annular area between the float and tube wall is large enough to allow the fluid to pass at the measured flow rate. The float position on the tube scale indicates the flow rate. The measurement principle is simple, passive and highly reliable — with no power required and no electronic components to fail.
BES 7200 Series — Clearview Variable Area Flow Meters
The BES 7200 Series Clearview variable area flow meter is BES Flowmeters' own-brand rotameter range. Features include:
- Borosilicate glass tube for clear float visibility and chemical resistance
- Available for liquid and gas measurement
- Panel-mount and in-line configurations
- Compatible with needle valves for integrated flow control
- Calibrated scales for water, oil, air and other fluids
- Optional alarm switches and transmitter outputs
MPB Industries Variable Area Flow Meters
MPB Industries produces a comprehensive range of variable area flow meters for industrial, medical, laboratory and specialty gas applications — including the 1200, 1700, 3000 and 3500 series for industrial liquid and gas measurement, and specialist ranges for anaesthetic gases and veterinary applications.
For the closely related rotameter range, see our dedicated page. For gas measurement specifically, see our gas flow meters. Request a quote or call (03) 5956 8685.
Frequently Asked Questions
A variable area flow meter (also called a rotameter) consists of a tapered tube and a float. As fluid flows upward through the tube, the float rises to a position where the upward flow force equals the float’s weight. The float position on the graduated scale indicates the flow rate. Variable area meters are simple, robust and require no power supply.
The 7200 Series is a range of variable area flow meters (rotameters) supplied by BES Flowmeters. Available in glass and metal tube versions, the 7200 Series suits a wide range of liquid and gas applications including water, chemicals, compressed air and inert gases. BES can supply in various sizes and material configurations.
Variable area flow meters are simple, low-cost and require no external power. They provide a direct visual flow reading without electronics, making them ideal for local indication in laboratories, process plants and utility systems. Metal tube versions are suitable for high-pressure and opaque fluid applications.
Variable area flow meters can measure water, light chemicals, oils and gases including air and nitrogen. Material compatibility between the float, tube and fluid must be verified for chemical applications. BES Flowmeters can advise on material selection for your specific fluid.
Variable area flow meters are calibrated for a specific fluid at a specific operating condition (density, viscosity) at the time of manufacture. If the actual operating fluid or conditions differ significantly from the calibration conditions, a correction factor may be needed. BES Flowmeters can supply meters calibrated to your specific requirements.