Open channel flow measurement can be a challenge in applications that require the placement of a flume in an existing pipe or channel. While most everyone is familiar with Parshall Flumes, in many cases, there are other flume options that can provide for equal or better accuracy and are better suited for a particular pipe or channel. Here are some examples of unique flume applications, all of which required the installation of a flume in an existing channel.
A municipality need to measure flow for stormwater sampling in an existing trapezoidal channel that was 7’-0” wide at the bottom and 26’-0” wide at the top. Based on the channel size and shape, the 2’ SRCRC Trapezoidal flume was selected because it could handle the widest range of flow rates within the head restraints of the existing channel. Custom inlet wing walls were designed to match the channel contours for a smooth flow transition with a minimum of on-site concrete work.
In another storm water sampling application. Flow measurement was required in an existing 6’ rectangular stormwater channel. A 42” Palmer Bowlus flume was chosen as it was the only flume that could handle the maximum expected flow rates with minimal head loss, and still fit inside the existing channel. A custom inlet approach section and outlet bulkhead were supplied to match the channel dimensions.
A steel mill needed to measure flow in an 8” pipe from a clarifier, but had limited room between the clarifier and the wall. A 6” Palmer Bowlus Flume with 8” pipe flanges was supplied because it was the shortest flume that could handle the flow rates and fit in the space available.
A dairy processing plant needed to measure flow from an 8” pipe and because of area constraints the only option was to place a flume in the existing drop manhole. For this application we supplied a 1’ H-Flume with a bulkhead and support bracket for a relatively quick and easy installation without the need for a long plant shut down.
For most Open channel flow applications there is usually more then one flume or weir that is capable of handling the required range of flows.
For help in selecting the best flume or weir for your application please contact your nearest representative. For downloadable flume flow charts and additional flume guidance, visit our Resource Center.