TinnerFlow
Transitions & Reducers ยท Transitions & Reducers

Equipment inlet transition

Fan/AHU inlet

ConnectionFlanged/flexible connector
SupportIndependent support

Before you start

  • Confirm the equipment inlet dimensions, airflow direction, transition geometry, flexible connector requirement, inlet cone or bellmouth details, and upstream fitting separation.
  • Check the negative-pressure condition and whether the connector can resist inward collapse.
  • Inspect the equipment flange, transition, supports, and inlet path.
  • Verify the inlet remains centered unless an approved offset is shown.

Tools and materials

Approved equipment-inlet transition, manufacturer adapter, flexible connector if specified for negative pressure, independent supports, gasket, compatible fasteners, sealant, level, laser, and inspection light.

Lay it out

  1. Establish the equipment inlet centerline and upstream duct centerline.
  2. Confirm the transition is concentric or offset exactly as designed.
  3. Keep turning fittings and obstructions away from the inlet as required by the approved design.

Set and support it

  1. Support the transition and upstream duct independently.
  2. Keep the flexible connector relaxed and supported.
  3. Hold the inlet connection centered.

Make the connection

  1. 1

    Verify the inlet flange and approved transition.

  2. 2

    Set the supported transition at the equipment centerline.

  3. 3

    Install the equipment-side connection.

  4. 4

    Install the flexible connector without inward slack that can collapse.

  5. 5

    Align and connect the upstream duct.

  6. 6

    Seal required joints.

  7. 7

    Inspect the inside for lips, obstruction, loose material, or collapsed fabric.

Check the install

  • The inlet remains centered and unobstructed.
  • The connector remains stable under negative pressure.
  • The transition is gradual and fully supported.
  • Equipment carries no duct weight.
  • No upstream fitting creates an unapproved disturbance.

Common mistakes

  • Offsetting the inlet transition without design approval.
  • Leaving loose flexible fabric that pulls inward.
  • Installing a hard turn directly at the inlet.
  • Using the equipment flange to support the upstream run.

Stop and ask

Stop if the inlet cone or transition is offset without design approval, the connector may collapse, or the equipment inlet dimensions do not match.