Flume Manholes
Flume Manholes provide a unique solution to solving the problem of how to accurately meter open channel flows in buried pipes. Openchannelflow flume manholes integrate our proven fiberglass flumes with fiberglass manhole barrels to provide a single-piece, watertight, and corrosion resistant solution that requires minimal installation time and virtually no maintenance.
Flumes available for integration include:
- Parshall (1” – 24”)
- Trapezoidal (Small 60° – 2” 45°)
- HS / H / HL (0.4’ HS – 2.5’ H)
For owners, fiberglass Flume Manholes provide:
- Confidence that the flume is installed correctly and with the necessary transitions to ensure accurate flow measurement (no questions from your monitoring agencies)
- Single source responsibility (no finger pointing between subcontractors)
- Low maintenance and repair costs due to the corrosion resistance of fiberglass to even the most aggressive of environments
- The ability to integral a much wider selection of flumes than can readily be accommodated in concrete structures (integrate the flume the best fits the flow)
- Minimal installation downtime
For contractors, fiberglass Flume Manholes provide:
- Single source responsibility (no finger pointing between subcontractors)
- Confidence that the flume is installed correctly and with the necessary transitions to ensure accurate flow measurement (happy customers)
- Virtually no warranty repairs when installed according to Openchannelflow’s instructions. Dig a hole, drop it in, and your done.
- Industry leading FiberLock equipment warranty – up to 5 years!
- Minimal installation downtime (minimizing pump around on active lines – better utilization of site equipment)
For consultants, fiberglass Flume Manholes provide:
- Single source responsibility (no finger pointing between subcontractors)
- The ability to integral a much wider selection of flumes than can readily be accommodated in concrete structures (integrate the flume the best fits the flow)
- Confidence that the flume is installed correctly and with the necessary transitions to ensure accurate flow measurement (happy customers)
- Industry leading FiberLock equipment warranty – up to 5 years!
- High levels of user satisfaction – users who have experience with fiberglass flow metering manholes almost exclusively specify their use on future projects – they are just that happy!
Openchannelflow offers a variety of manhole cover styles, diameters, and options to tailor our Flume Manholes to your specific flow monitoring needs.
Top styles include:
- Full opening domed top for maximum access
- Flat cover aluminum hatches for pedestrian areas / low profile installations
- Large diameter opening highway loading reducers tops (using customer supplied grade rings, cover, and frame)
Each unit comes as a single, watertight piece with the following features:
- Corrosion resistant interior barrel surface
- OHSA-compliant fiberglass ladder with non-slip ladder rungs
- Integrated cover (see above)
- Closed base
- External base mounting / anti-flotation flange with cushioning pad
- Inlet/outlet piping with flexible couplings for quick pipeline connection (flanges and caulking collars optional)
- Exterior corrosion resistant gel coat barrier with U.V. inhibitors
In addition, Openchannelflow offers a wide array of optional accessories to help you customize your Flume Manhole to fit your specific needs, including:
- Integral fiberglass benches
- Additional manhole thru-wall couplings (for power / controls / etc.)
- Full and half diameter fiberglass grating platforms
- General purpose and hazardous location lighting
- Powered and unpowered ventilation
- Equipment shelves and mounting panels
- Two-piece construction for ease of handling
Manhole diameters available are:
4’ [122 cm], 5’ [152 cm], 6’ [183 cm], 7’-8” [234 cm]1
4’ [122 cm], 5’ [152 cm], 6’ [183 cm], 7’-8” [234 cm]1
1Aluminum hatch and highway loading top styles only.







