Taps & Takeoffs · Taps & Takeoffs

High-efficiency bellmouth tap

Rectangular plenum/main

ConnectionBellmouth flange
SupportIndependent branch support

Before you start

  • Confirm bellmouth size, airflow direction, mounting surface, and branch route.
  • Inspect the radius and flange for distortion.
  • Verify the opening can be cut precisely.
  • Check the plenum or main for internal conflicts.

Tools and materials

High-efficiency bellmouth tap, template, cutting tools, clamps, approved fasteners, sealant, branch support, and deburring tools.

Lay it out

  1. Mark the precise opening.
  2. Orient the bellmouth radius into the airflow as designed.
  3. Align the branch centerline.

Set and support it

  1. Support the main or plenum face if required.
  2. Clamp the bellmouth evenly.
  3. Provide downstream branch support.

Make the connection

  1. 1

    Cut and deburr the opening.

  2. 2

    Set the bellmouth in the correct orientation.

  3. 3

    Align the branch outlet.

  4. 4

    Clamp the flange flat.

  5. 5

    Fasten evenly.

  6. 6

    Seal the perimeter.

  7. 7

    Connect and support the branch.

Check the install

  • The radius is smooth and undamaged.
  • The fitting is not installed backward.
  • The opening is clean.
  • The branch is aligned and supported.

Common mistakes

  • Installing the bellmouth backward.
  • Distorting the radius with clamps.
  • Cutting a rough opening.
  • Letting downstream duct pull on the fitting.

Stop and ask

Stop if the fitting is installed backward, distorted, or cannot seat fully on the mounting surface.