When a Variable-Area Flow Meter is Not a Rotameter

Variable-Area Flow Meter
Orange Research Variable-Area Flow Meters

Designed to overcome the inherent shortcomings of rotameters, Orange Research variable area flowmeters provide an excellent alternative for those applications where rotameters fall short. While rotameters are elegantly simple and perform well in most cases, users do complain they are difficult to read (particularly with dirty or opaque fluids), their pressure ratings are too low, and their mounting options are restrictive.

Orange Research high pressure variable area flowmeters are designed to overcome these drawbacks. First, they offer large, highly visible dials with bold markings and characters that are easy to read from a distance. Second, they are constructed from metal bar stock, making them suitable for high line pressures. Finally, Orange Research variable area flowmeters are not position sensitive, and therefore can be mounted without concern of orientation.

Like rotameters, these variable area flowmeters are mounted directly in the flow stream, but with bodies machined from solid blocks of metal, they handle high-pressure applications of up to 5000 PSI, as opposed to approximately 150 PSI for rotameters. This makes their use a natural for hydraulic and pneumatic systems.

Designed for medium-to-high flow applications, they use a movable Delrin cone flowmeter sensor resting in a precision orifice. Changes in fluid flow cause the sensor to move against a stainless steel spring while the flow rate is indicated on an easy-to-read dial face.

Flowmeters with bodies (and wetted parts) of aluminum, stainless steel or brass are available in sizes from 2.5 inch to 4.5 inch. They can be supplied with variety of reed switches, relays and transmitters. For example:
  • SPST switches are offered normally open (N.O.) or normally closed (N.C.). 
  • SPDT reed switches also are available. 
  • DPDT relays are offered for high inductance applications, such as those incorporating motors or solenoids. 
  • Transmitters offer a current or voltage output.
For liquids our high flow flow meters are calibrated to customer-specified specific gravity and viscosity of the fluid to be measured (up to 150 CS). Otherwise, standard calibration is on water at 70° F. For oil service, high pressure flow meters are calibrated using oil (specific gravity 0.86 CS at 74° F). Special calibration is available to meet customers' specific gravity and viscosity requirements using selected fluids and a conversion procedure. Standard calibration is for horizontal mounting; vertical is offered at no charge.

For more information about Orange Research variable area flowmeters, contact Advance Instruments. Call them at (888) 388-6446 or visit their web site at https://advanceinstruments.com.