TinnerFlow
Taps & Takeoffs · Taps & Takeoffs

Rectangular straight tap

Side of rectangular main

ConnectionFlanged/screwed collar
SupportIndependent branch support

Before you start

  • Confirm tap size, location, branch route, airflow direction, and approved opening before cutting.
  • Check the main for seams, crossbreaks, joints, reinforcement, dampers, access doors, and nearby fittings.
  • Lay out from a reliable main-duct reference.
  • Support the cookie before the final cut.

Tools and materials

Rectangular straight tap, tape, square, marker, approved cutting tools, hand seamer, clamps, approved fasteners, sealant, branch support, and deburring tools.

Lay it out

  1. Mark the opening from the approved branch centerline.
  2. Keep the opening clear of reinforcement and seams.
  3. Square the throat to the main, not to a crooked ceiling line.

Set and support it

  1. Support the main if the panel could distort.
  2. Install or mark the first branch support.
  3. Clamp the tap flush before fastening.

Make the connection

  1. 1

    Cut the opening while holding the cookie.

  2. 2

    Remove the cookie and deburr the edge.

  3. 3

    Set the tap flush in the opening.

  4. 4

    Square the throat and align the branch.

  5. 5

    Clamp the flange evenly.

  6. 6

    Fasten from the corners outward.

  7. 7

    Seal the full perimeter.

  8. 8

    Connect and independently support the branch.

Check the install

  • The tap sits flat with no rocking.
  • The branch is square to the main.
  • The opening is clean and the seal is continuous.
  • The branch does not pull on the tap.

Common mistakes

  • Fastening before squaring the tap.
  • Letting the cookie fall into the duct.
  • Cutting across a crossbreak or reinforcement.
  • Using the branch to pull a crooked tap into line.

Stop and ask

Stop if the opening crosses reinforcement, a seam, liner damage, a damper, or another fitting, or if the branch cannot align without forcing the tap.