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Slide for Montana Flumes
Slide for Montana Flumes
Slide for Montana Flumes
Slide for Montana Flumes

The Montana flume is a modification of the widely used Parshall flume.  The flume takes it shape from the hourglass of the Parshall, but omits both the throat and discharge sections.

Montana flumes are inexpensive and accurate ways of measuring the flow of water in a variety of applications.  

Just like the Parshall flume, the Montana flume is available in 22 different sizes – although, in practice, Montana flumes larger than 48-inches in size are rarely used.

Like the Parshall flume on which they are based, Openchannelflow manufacturers Montana flumes in:

  • Aluminum
  • Fiberglass (FRP)
  • Galvanized steel
  • Stainless steel

Of the materials, fiberglass is most commonly used to measure sanitary / municipal sewage flows, while stainless steel is most common for discharges with corrosive chemicals, high temperatures, or abrasive solids or where vandalism is a concern. Where only lightweight and abrasion resistance are sought, aluminum is an excellent material choice.  Finally, for water rights and irrigation applications, most Parshall flumes are made from galvanized steel.

Montana Flume Accessories

Most of the accessories Openchannelflow manufacturers for our Parshall flumes are also available for our Montana flumes, including:

  • Inlet piping / end connections
  • Flow condition options
  • Flow meter mounts
  • Sampler / parameter mounts
  • Custom configurations (nesting, extended / reduced sidewalls, etc.)

Montana Flume Applications

The versatility of the Montana flume has seen it used in a diverse number of applications, including:

  • Sewage Treatment Plants
  • Watershed Monitoring
  • Edge-of-Field Runoff
  • Dam Seepage 
  • Stream Gauging
  • Industrial Discharge Monitoring
  • Mine Discharge
  • Irrigation Canals
  • Spring Discharge Measurement

How a Montana Flume Operates

A Montana flume is a restricting structure that accelerates flow through a contraction of parallel sidewalls. Lacking the throat and discharge sections of the Parshall flume, flow out of the Montana flume spills directly out of the end of the flume.  The contraction and spilling discharge accelerate the flow from a slow subcritical state to a supercritical one.  

As a result, the flow can be accurately determined in the upstream, converging section of the flume by taking a single depth reading at a specific point of measurement.

More About Montana Flumes

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