Understanding the Elements of a Flume

You already know that a flume is an essential element of your flow measurement and management system. Do you, however, understand how the various sections of your flume work together to provide you with reliable numbers? Check out the elements of a flume, and learn what each part does to manage and monitor flow for your operations.

The Elements of a Flume

There are six major elements of a flume: the exterior, dimensional bracing, the flow surface, anchor clips, flanges and stiffening ribs. Each serves an important purpose in the functionality of a flume.

  1. The Exterior
    The exterior of the flume is the outside where accessories and anchor clips are molded or attached. It may be rough and appear “unfinished”; this is because the surface area isn’t exposed to flow, so smoothness isn’t needed. In a fiberglass flume, this is the part that may be exposed to sunlight, so it will often be covered with a UV protective gel coating to keep it from solar damage.

  2. Dimensional Bracing
    The dimensional bracing is generally on top of the flume, and it makes sure that the flume maintains its shape so the walls don’t get convex or concave, which can change the flow within the flume. It keeps the flume rigid on top where there is no floor to keep it steady and stable. The flow of water inside creates pressure that will draw the walls inward almost like a vacuum, so keeping the shape rigid is essential. These braces can be chemically bonded, bolted or welded, depending on the individual flume.

  3. Flow Surface
    The flow surface is the inside of the flume. This is the surface that gets exposed to the liquid that moves through. On fiberglass flumes, this will have a smooth, glossy, glass-like finish. The smooth finish allows water to move through unimpeded, so it’s important to keep it clear of growth, scum and other buildup.

  4. Anchor Clips
    Anchor clips are used to keep the flume in place while it’s being installed. These clips are L-shaped and attached to the exterior via chemical bonding, glassing or welding. Anchor clips are used to key the flume to its concrete base using wire or rebar to secure it before concrete is poured. They are used in conjunction with materials like sandbags to keep the flume stable and steady. Anchoring clips can also be used to level the flume on smaller devices.

  5. Flanges
    Flanges keep the flume rigid along the long, straight edges. End flanges are sometimes extended on earthen channel installs to help stop scouring at the inlet and outlet, and stop the flow from completely bypassing the flume. They are also the location where dimensional bracing, accessories and transitions are mounted.

  6. Stiffening Rib
    Stiffening ribs provide stiffness along the sides and floor of the flume to protect its unbroken, flat surfaces. In fiberglass flumes, these are usually made by laminating a form secured to the outside of the flume. Usually, they are made of engineered foam, which is easy to shape and design to the specific needs of the lamination process.

Shop Fiberglass Flumes at Tracom

If you’d like more information on the parts of a flume and how it works, Tracom can help. Check out our selection of flumes and get in touch with us for answers to your questions or to place an order today.