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The Parshall flume is a fixed hydraulic structure originally developed to measure surface water and irrigation flows. Recently, research has been conducted to see if Parshall (and Venturi) flumes also provide a benefit in aerating the flow streams that they are used to measure.…

As Parshall Flumes get larger they become more restricted in their uses. The 72-inch Parshall Flume is primarily used to measure flows at treatment plants, water rights, and surface waters. Due to its size, the 72-inch Parshall Flume usually ships in two pieces. The 72-inch…

48-inch Parshall Flumes have been used over the years to measure flow in a several different applications mine dewatering, surface waters, stream, rivers, water rights, and wastewater treatment plants. The 48-inch Parshall Flume is useful in a number of applications:

The 1-inch Parshall Flume is the smallest of the 22 standard Parshall flume sizes. The small size means that it is relatively limited in its use. 1-inch Parshall Flumes cannot be used on unscreened sanitary flows as they will clog. The 3-inch Parshall Flume is the smallest…

The Extra Large 60º V Trapezoidal Flume is useful - providing good low-end accuracy while still allowing connection to larger (up to 12-inch [30.48 cm]) pipes. The flat-bottomed design and v-shaped cross section mean that the flume passes solids well. The Extra Large 60º V…

Unlike the Palmer Bowlus flume which was specifically designed to be used in-line with sewer pipes and conduits, Parshall flumes were originally developed to measure flows in irrigation channels and natural streams / rivers. Over the years, though, Parshall flumes have been…

One of the greatest benefits of Openchannelflow's fiberglass manholes is corrosion resistance. In a traffic loading configuration, a grade ring / frame / cover set is still required to bring the manhole up to grade. Made out of traditional materials, these items are still…

The 24-inch Parshall Flume is a popular size of Parshall Flume for measuring surface water flows, water rights, and sanitary flows at treatment plants. The 24-inch Parshall Flume can be useful in a number of applications, including:

The 3-inch Parshall Flume is one of the last flumes developed in the Parshall series. The flume can be used equally well to measure sanitary flows as well as surface waters. It is important to note that the 3-inch Parshall flume is the smallest Parshall Flume size that can be…

The 9-inch Parshall Flume is a popular size in the Parshall Flume family. It is equally at home measuring surface waters, wastewater flows, and water rights. The 9-inch Parshall Flume is useful in a number of applications, including:

The 12-inch Parshall Flume is one of the most popular sizes of the Parshall Flume family. The flume is equally at home measuring sanitary wastewater at a municipal treatment plant as it is measuring water rights on The Western Slope. The flume is regularly used to measure the…

For years Openchannelflow has offered staff gauges integrated into our flume, weir, and manhole products. Over time, though, we have been asked to expand our offerings to include free-standing Staff (Level) Gauges.

On the face of it, mounting a staff gauge on a weir plate to get the head / flow rate seems like a good idea. It works for on a flume, why wouldn’t it work on a weir? The problem is, as we have seen earlier, the water level in a weir pool draws down as the flow approach the…

A common problem in using Weirs to measure water flows is reading the flow level too close to the weir plate. To understand why this is a problem we need to look at what happens as flow travels through the weir pool and then over the weir crest.

We often talk about how OCF tried to sweat the small things. One of the items that we have focused on is our flow meter sensor mounting brackets. Many of the designs currently on the market show, what we believe to be, a "good enough" philosophy - that the brackets hold the…

The Palmer Bowlus flume – quite possibly the second only behind the Parshall flume for measuring wastewater flows – suffers from a number of problems when it comes to its operational use.

One question we get asked on a regular basis is: can flow free fall off the end of a Parshall flume? The answer is: yes – and if possible, this is the preferred method of discharge! To understand why, we need think about how a Parshall flume operates.

The H flume is a class of flumes developed by the Soil Conservation Service (USDA) to measure runoff from catchments and experimental plots. Really more of combination between a flume and a weir, the H flume provides excellent low flow handling, solids passage, and a wide…

There are many, many different ways to mount or install an H flume, some of them quite inventive! Here we’ll go over the basics of installing an H flume in an earthen or concrete channel. Keep in mind that these guidelines are just that: guidelines. Proper sizing is the first…

Measuring flow in a flume should be a straightforward affair. Unfortunately, we get more calls and inquiries on where / how to measure flow in a Palmer Bowlus flume than all other flumes combined so we thought that we would go over it set the record straight. To better understand…