Flumes and Weirs - Open Channel Flow

Open channel flow measurements have been done using flumes and weirs for many, many years.  It is usually recommended by State engineers and hydrologists to use a flume when monitoring flows in irrigation and other open channel applications. We have been supplying flumes and weirs for over a decade and can help you choose the appropriate model for your needs.  Or, simply call us and order the flume you have decided to use. (Download Brochure)

Parshall Flume

A very common critical-flow flume is the Venturi Flume (Parshall), which was developed and calibrated by Dr. Parshall of the U.S. Soil Conservation Service in1922. The essential change introduced by Parshall was a drop in the floor, which produced supercritical flow through the throat of the flume. This seemingly perfected device was named the Parshall Measuring Flume, which is not patented and the discharge tables are not copyrighted.

The constricted throat of the flume produces a head that is related to discharge. The level of converging section followed by the downward sloping floor in the throat gives the Parshall flume its ability to withstand relatively high degrees of submergence without affecting the rate of flow. The converging upstream portion of the flow accelerates the entering flow, helping to eliminate deposits of sediments, which would otherwise reduce measurement accuracy. The approaching flow should be relatively free of turbulence, eddies, and waves if accurate measurements are expected.

We offer most sizes of Parshall flumes in fiberglass.  Contact us for pricing

Download a Brochure on sizing and installing a Parshall Flume.

EZ Flow Ramp Flume - Galvanized Steel

EZ Flow flumes are made of high quality galvanized steel for years of trouble free service. They are designed with extremely rigid “flanged” construction throughout and utilize heavy cross bracing. The design allows the installation of the flume in locations with heavy soil backfill or in concrete channels.

Many different features have been tried in past adjustable flume designs. For example, fixed, portable, and vertically movable gates have been described by Bosetal. (1991). Small water trays have been used for leveling, as well as radial gates and vertical slide gates to regulate and estimate flow rate. Their range of utility is limited, and accuracy is a persistent problem in these past designs, with errors frequently exceeding +/-20%. The EZ Flow Ramp Flume represents the “state-of-the-art” in flume design, achieving amazing flow metering accuracy.

Extensive testing and evaluation under field and laboratory conditions, have shown the EZ Flow Ramp Flumes consistently achieve accuracies to within +/- 3%, when properly installed. The increased flowvelocity in the throat section discourages sediment accumulation in this important part of the flume. The approach section near the gage, while somewhat less self-cleaning, is tolerant of considerable sediment accumulation before significantly altering the flumes function. This provides for long periods of time between cleaning and maintenance.

Download an EZ Flow Ramp Flume brochure.

Palmer-Bowlus Flume

This flume was specifically designed to be a simple and effective waste water flow-measuring device. The flume is essentially a restriction in the channel and is sized according to the width of the flume, this type of flume is most often attached to a pipe and is sized based upon the pipe size (in most cases).  They are often used in manholes and above ground vaults.

We offer fiberglass Palmer-Bowlus flumes in a variety of sizes.

Capacities of Palmer-Bowlus Flumes

Contact us for pricing

Other Flumes

We offer other styles and types of flumes.  Below is a list of flumes that we can provide.  If you are seeking a custom flume or a flume not shown please contact us for pricing and delivery information.

• H-Flume
• Cutthroat Flume
• Weir Boxes
• Weir Plates
• V-Notch Weir
• Montana Flume

Custom Detached Stilling Wells

We also offer custom designed - detached - stilling wells.  We can build these stilling wells to allow you to attach a measuring and recording device to your flume or weir.  We can build them out of PVC or Steel Corrugated Pipe.  Below is an example of a custom stilling well built out of 12 inch diameter corrugated pipe.  It has a 3/4 inch connection on the bottom and a half shelf welded inside to allow mounting of a shaft encoder or float and pulley.  We can build stilling wells ranging in size from 2 inch in diameter to 24 inch depending on your needs.  Contact us for pricing and delivery information.