The Hedland variable area flow meter product line features over 18,000 inline flow meters to measure oil, phosphate esters, water, water-based fluids, pressurized air and other compressed gases. Meters designed for liquids are compatible with viscosities ranging from 40…500 SUS (4.2…108 cSt).
From 1/4…3 inches (6…76 mm), Hedland flow meters and flow switches provide quick visual indication on an easy-to-read linear scale. Hedland MR Transmitters deliver flow rate on a digital display and/or analog output. With models available for standard and high temperature applications, Hedland products are perfectly suited for the most demanding applications in fluid power, oil and gas, automotive, semiconductor, mining and discrete manufacturing. Additionally, the products are available in aluminum, brass, stainless steel, polysulfone or Radel® bodies to deliver cost-effective solutions for applications based on fluid compatibility, temperature and pressure.
Hedland products work well for both new and retrofit applications as they do not require flow straighteners, have no special piping requirements and may be installed in an orientation. In addition, Hedland instrumentation is available with a variety of end fitting options including, SAE threads, NPTF threads, BSPP threads (BSPT for 3”), PVC socket and swivel fittings, code 61/62 flanges and more.
Principle: The Hedland flow meter is a variable area instrument. A precision machined, sharp-edged orifice located within the piston assembly forms an annular opening with the contoured metering Cone. The piston assembly carries a cylindrical PPS/ ceramic magnet that is magnetically coupled to an external flow indicator that moves precisely, in direct response to movement of the piston. A calibrated spring opposes flow in the forward direction. This spring decreases viscosity sensitivity and allows the flow meter to be used in any position, including inverted.