Ellipse Pitot Tube Annular Flanged Flow Meter

Preso’s patented elliptical design outperforms and provides greater accuracy than traditional differential pressure flow measurement devices. This differential pressure flow meter is designed with a series of ports facing the upstream velocity pressures, as well as flow sensing ports strategically located ahead of the trailing edge flow separation.
The multi-ported, self-averaging flow element consists of an elliptical shape with two independent flow sensing chambers. The impact velocity sensing holes (high pressure) are located along the leading edge and the true static sensing holes (low pressure) are on the exterior probe side. Model AF comes with instrument shut-off valves with connections to accept a transmitter or direct indicating meter.

  • Applications:
    • Air
    • Liquids
    • Gases
  • Pipe Sizes:
    • 2 to 72 inches (50 to 1830 mm)
  • Pressure:
    •   Vary per flange ratings
  • Temperature:
    • Vary per flange rating
  • Accuracy:
    • ± 0.75% of reading
  • Turndown Ratio:
    • 17:1 with no vacuum effect


  • Patented elliptical design outperforms traditional devices
  • Accuracy: ±0.75% of reading, repeatability: ±0.1% of reading
  • Turndown Ratio: 17: 1; no vacuum effects
  • True static pressure measurement rather than a calculated value
  • Single point pipe entry for DP, temperature and static pressure
  • No dampening software required
  • Lowest pressure loss in industry (typically 3% of DP in a 12″ line) due to its patented aerodynamic profile
  • Overcomes loss of accuracy caused by fluid separation at the sensor body
  • No moving parts equals long, trouble-free service life
  • NIST traceable calibration: Optional independent labs