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Flow measurement in arctic locations can be extremely difficult. By their very nature, the locations are remote, equipment is limited, flows are highly seasonal, and frost heave is an ever-present concern. Of these problems, frost heave can be the most difficult to resolve.

We see Parshall Flumes at wastewater treatment plants measuring sanitary flows so often that sometimes we forget the original reason that the Parshall Flume was developed – to measure irrigation flows. With 22 sizes available, Parshall Flumes are capable of measuring flows from…

One of the primary advantaged of fiberglass flow metering manholes is the ability to accommodate flumes much larger than will fit inside the manhole. By being able to laminate the flume to the manhole barrel, flumes can readily extend upstream / downstream of the manhole barrel…

One of the advantages of using a device like a Parshall Flume is that, properly installed and applied, there is NO NEED TO CALIBRATE THE FLUME! Now that doesn’t mean that you don’t need to periodically check to make sure the Parshall Flume isn’t clean and level, or that the…

At the turn of the last century, the Venturi flume was one of the few devices available to measure irrigation flows. While popular at the time, the Venturi flume had it problems.

The USBR - U.S. Bureau of Reclamation (a part of the Department of the Interior) has long been a source of information on the Parshall Flume - particularly with their Water Measurement Manual (WMM).

In talking with customers about weirs, we run into two common misconceptions. The first misconception is that weirs can read down to zero – that there is no minimum head. The second is that weirs are more accurate at these flows than flumes. Unfortunately, both assumptions are…

A Packaged Metering Manhole (PMM) is a fiberglass manhole into which a primary device has been integrated. In addition to the above, Packaged Metering Manholes allow the integration of primary devices larger than would otherwise be able to be easily accommodated in concrete…

One of the most common uses of flumes today is to measure sanitary flows; whether this is at an industrial discharge, mobile home park, resort, or wastewater treatment plant. Unfortunately, flumes are often selected bsed solely on their ability to handle anticipated flows –…

Portable weir plates are a good way to stretch your research dollars. Instead of the traditional approach of having a weir plate custom fabricated for each installation, Openchannelflow has simplified the process by developing a standard weir carrier with four interchangeable…

There are two conditions of flow that can occur in a Parshall Flume: Free-flow occurs in a flume when there is insufficient backwater to reduce the discharge through the flume. The primary advantage of free-flow is that the level only needs to be measured at a single point (the…

Flumes installed in earthen channels frequently experience the problems of upstream flow bypass and downstream scour.

The Bureau of Reclamation was tasked with conducting a basin-wide effort to define the problems, identify solutions, and options relating to protecting and increasing water supplies and improving the health of a high mountain watershed.

Stilling wells are chambers isolated from, but connected to, the main flow of water in a flume, weir, or channel. Isolating the stilling well from the main flow via a small connector dampens or quiets the body of water in stilling well, while still allowing it follow the steady…

Regardless as to which flume you are installing, there are general guidelines that apply to any installation. With these steps in mind, you are on your way to a trouble-free flume installation!

The most common method of transitioning flow from a channel into a Parshall flume is through the use of 45° inlet wing walls. The approach is straight-forward and the installation simple, but is it correct?

Time and again the question arises: how durable is a fiberglass flume anyway? To understand the answer, it is important to understand the nature of fiberglass. Fiberglass (aka glass-reinforced plastic, glass-fiber reinforced plastic, glasfaserverstärkter kunststoff , FRP,…

Weir boxes are frequently fabricated without the use of a baffle upstream of the point of measurement. The omission of a baffle plate (sometimes called a surge plate) saves both space and money, but at what cost? In applications where the velocity profile is normal and the…

Since its development at the beginning of the last century, the Parshall Flume has proven to be a versatile and long-lived invention for the measurement of water in open channels. More Parshall Flumes are sold for water measurement than all other flume types combined.

Metering manholes are a convenient way to measure flows in a wide range of applications, including: wastewater treatment plant headworks / influent, treated effluent, in-plant flows, industrial discharge, or monitoring the flow of sewage in a collection system. Capable of…