Cover Options for Flumes and Weir Boxes

Covers are used over flumes and weir boxes for a number of different reasons: eliminating inflow, aesthetics, operator safety, foam, sensor protection, or containing foaming / splashing flows.

To meet these applications, Openchannelflow offers solid and transparent covers in both fixed and hinged configurations.

Solid Covers

Comprised of sheet fiberglass, stainless steel, or aluminum, solid covers are used in applications where cost is a concern, where the operator / foot traffic may present, or where owner wants to keep prying fingers (and eyes) away from the flume or weir box.

galvanized steel Parshal flume with cover - hinged over stiling well

Depending upon the site, solid covers are available as flat sheets or as diamond plate. Flat sheet solid covers are used where the flume or weir box will not experience foot traffic. Diamond plate covers are used where foot traffic will be present.

hinged diamond plate cover cover a fiberglass weir box with staff gauge

Flat sheet covers can be provided with observation windows to allow the operator to check the level in the flume or weir without the need to remove the cover. Solid covers can be provided as:

A single, bolt-down piece
Segments to allow selective removal
Hinged, for quick flip-up observation of the flow steam
Or some combination of the above

Solid covers can also have observation windows of UV / scratch resistant polycarbonate mounted in them. The observation windows can themselves be fixed or hinged. Hinged observation windows make it easy for an operator to take water quality samples.

stainless steel weir box with fixed observation window in cover

Where a more rugged cover cover is requried, covers made from fiberglass, stainless, or aluminum diamond plate are also available to cover flumes and weir boxes.

Aluminum diamond plate cover with ultrasonic sensor cut-out mounted on a fiberglass weir box

Like solid covers, diamond plate covers are available as fixed, hinged, or combination covers. As they are intended for areas where foot may be present, diamond plate covers are not usually available with observation windows. Diamond plate covers are also not suitable for vehicle traffic applications - there a Packaged Metering Manhole with a traffic rated cover is recommended.

flume cover with hinged observation window

Transparent Covers

Transparent covers are available for weir boxes and smaller flumes. While they do cost more than the solid covers discussed above, they allow the operator to view the entire flume or weir.

clear polycarbonate covers over palmer-bowlus flumes

Transparent covers - available clear and tinted versions - are made from polycarbonate sheet which has a clear coating to help prevent scratching and which provide protection from UV degradation.

Both solid and transparent covers are available with cutouts for bubbler / sampler tubes, probes, or ultrasonic sensor beams as necessary.

Fiberglass weir box with bolt-down cover