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Openchannelflow offers a variety of top styles to allow you to customize our fiberglass manholes to suite your specific site needs.

Each top style is designed for a specific type of application or to solve a particular access requirement.

Of the top styles offered, the Aluminum Top and Domed Top styles are considered to be "complete" in that no additional components are required to finish the installation.

The H-20 Traffic Reducer requires grade rings, a frame, and a cover to complete the installation. These can be either locally sourced or Openchannelflow can provide a composite stack with the fiberglass manhole for a complete solution.

Open Top manholes typically require a dedicated equipment shelter over them - or some other protection - to limit unauthorized access and the possibility of inflow.

Aluminum Top

  • For pedestrian walkways or low-profile installations
  • Available in watertight and non-watertight areas
  • An array of accessories available
  • Sizing:
    • Flush with or just above the surface grade
  • Available for:
    • 4', 5', 6', and 8' [1.22, 1.52, 1.83, and 2.44 m] diameters

Fiberglass Domed Top

  • For grassy (non-traffic/pedestrian) areas

  • Most popular

  • Fully opening for maximum access

  • Easy entry / exit

  • Heavy-duty stainless steel hardware

  • Sizing:

    • 12 to 18-inches [30.48 to 45.72 cm] above the surface grade

  • Available for:

    • 4', 5', and 6' [1.22, 1.52, and 1.83 m] diameters

H-20 Traffic Reducer

  • For traffic / parking lot / loading dock / warehouse floor areas

  • Large 31 3/4-inch [80.65 cm] standard opening

  • 22 1/2 and 38-inch [57.15 and 96.52 cm] openings available

  • Optional composite grade rings, frames, and covers available for a full composite solution

  • Sizing:

    • 12-inches [30.48  cm] below the surface grade

    • For customer supplied grade rings, frame, and cover

  • Available for:

    • 4', 5', and 6' [1.22, 1.52, and 1.83 m] diameters

Open Top

  • Like the name implies, an open area at the top of the manhole
  • Typically covered with a hinged, narrow opening fiberglass grating
  • A good idea when the manhole is covered by a shelter or has access restricted
  • Wide array of accessories available

  • Sizing:
    • Usually flush with or just above the surface grade
  • Available for:
    • 4', 5', 6', and 8' [1.22, 1.52, 1.83, and 2.44 m] diameters

More About Top Styles

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