The Hedland Flow Meter For A.P.I. Oil / Caustic and Corrosive Liquids is a variable area flow meter with ranges from (0.1 to 1.0 GPM) to (10 to 100 GPM). The meter provides direct readings and can be installed in any position. This rugged meter is made with a T316 Stainless body, piston and cone. It also features a 360° rotatable guard/scale, good viscosity stability and is relatively insensitive to shock and vibration. It is rated to handle pressure of 6000 psi (some models), temperatures up to 240°F and has an accuracy of ±2% full scale.

The measuring principle uses a sharp-edged Orifice, located within the piston assembly which 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 Indicating Magnet which moves precisely in direct response to movement of the piston. A calibrated Spring opposes flow in the forward direction. Repeatability is ±1%.