TinnerFlow™2nd YearYELLOW · Check FirstRound Reducers / Mechanical Fastening
A reducer that separates was not mechanically engaged and sealed for the load. Re-seat, fasten, and seal it by the approved pressure-class detail.
Round reductions can see thrust, vibration, and pressure changes. Foil tape and a couple light screws are not a structural joint on a demanding run.
Support the fitting, check insertion depth, use the approved fastener pattern, and seal with the correct pressure-rated mastic/tape system. Replace damaged collars or distorted pipe ends.
Do not rely on foil tape as the only thing holding a round reducer in place.
A separated reducer can dump airflow, damage ceilings, fail testing, and create unsafe loose duct.
Final direction belongs to the foreman, approved drawings/specs, manufacturer instructions, pressure/material schedule, employer policy, and AHJ/code requirements.