Flow-Tronic Gauges

Internal Diameter Measuring Gauges

The Flow-Tronic range of gauges are designed for the precise measurement of internal pipe diameters from a simple tap.

Initially designed as a tool associated with TORPEE-MAG multi-point insertion electromagnetic flowmeters, the instrument can however be used independently of these products to measure the real internal diameters of pipes.

In many cases, especially in older pipes, the internal diameter may differ significantly from the initial diameter due to corrosion and various deposits over time (rust tubers, scale...).

Even for new pipes or pipes with little risk of deposits, the exact specifications of the pipes may be unknown (composition and thickness of the coating).

However, precise knowledge of this diameter is necessary in particular for the operation of flowmeters in full pipes, to convert the measured velocities into flow rates (electromagnetic flowmeters, ultrasonic flowmeters ...).

Flow-Tronic gauges are adapted to a very wide range of pipe diameters thanks to an original concept of rods assembled in segments; this concept also makes it possible to limit the constraint of the necessary clearance height.
Based on a very easy to use system of stops and locating rings, they can be used on pressurized pipes, without stopping the flow.


  • Real internal diameter measurement of any full pipe for accurate conversion of velocities measured by a flowmeter into flow rates (insertion flowmeters, standard electromagnetic flowmeters or non-intrusive flowmeters such as transit time or Doppler type ultrasonic flowmeters)
  • Internal diameter measurements prior to the installation of a single point insertion flowmeter HydrINS 2/ HydrINS 2 Mini, to allow the precise positioning of the measuring electrodes in the center of the pipe (or 1/8th depending on the application).
  • Any other need for information about internal pipe diameters (e.g., evaluation of loss of network capacity)

Main benefits

  • Can be used on pipes in operation and under pressure
  • Ease of use
  • Robust design
  • Wide range of possible diameters and limited clearance height constraints due to the segmented rod assembly
  • Presence of a Quick Connect pressure tap (useful for checking the tightness)


  • 2 models are available, differing in the range of measurable internal diameters and the size of the socket (with NPT or BSP type threads):
    — 1.5'' NPT/BSP, for pipe diameters from 100 mm to 1500 mm (4'' to 60'')
    — 2'' NPT/BSP, for pipe diameters from 1000 mm to 2500 mm (40'' to 98'')
  • Design:
    — Metal rod comprising of a body with a threaded portion for fixing on the tap and different segments which can be assembled according to the dimension of the pipe
    — Standard length stop (foot of the rod)
    — Two locating rings equipped with plastic clamping screws (top and bottom collars)
    — Handle allowing the alignment of the gauge and facilitating the 180° rotation of the rod when the stop is raised

Related products

  • Pipe thickness gauges
  • HydrINS2 and TORPEE-MAG insertion electromagnetic flowmeters

Related pages


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