Flow MD Small Volume Provers

Flow MD (FMD), the Technology Leader in Small Volume Unidirectional Captive Displacement Provers offers a comprehensive line of small volume provers (SVPs).


Flow Management Devices is the Technological Leader in design, engineering, and manufacturing of Small Volume Provers. Started in 2007 with the goal of “Continuously Improving Liquid Measurement Technology,” Flow MD’s patented prover design provides an accurate and fast measurement with minimal product displacement. Designed to be easy to operate, with self-diagnostics and long-wearing seals made of proprietary PTFE blends.

Our unique and compact prover design utilizes pulse interpolation electronics, a patented drive end, a motor driven piston with durable carbon fiber belts, a smooth bore cylinder, a poppet valve, and optical position sensors. The Flow MD line of Small Volume Unidirectional Captive Displacement Provers incorporates Double Chronometry as recognized by API 4.6 and is compliant with API 4.2 Direct Master Meter Proving.

With the recent release of the 4th Generation proving technology, FMD provides a comprehensive line of Unidirectional Captive Displacement Provers or Small Volume Provers that include twelve sizes with flow ranges from 100 GPM to 24,500 GPM (142 BPH to 35,000 BPH) and a 1200:1 turndown ratio.

Mounting options include permanent installation or truck/trailer mounting for field proving.

FMD Provers can be used to calibrate/verify the accuracy and repeatability of the following meter types:

  • Coriolis Mass
  • PD (Positive Displacement)
  • Turbine
  • Ultrasonic

Applications Include:

  • High-Pressure NGL's
  • Vanous Process Fluids
  • Cryogenic
  • Refined Products
  • Crude Oil

Flow MD has seven (7) patents and two (2) pending.