Butyl gasket tape was stretched thin on a TDC/Ductmate flange

For TDC/Ductmate, gasket goes on one flange face only. Keep it relaxed and continuous through the corners; do not stretch it thin, double-gasket both ducts, or bolt over a gap/fold.

Stop if

• Don't pull or stretch that butyl tape thin just to make it fit the rim. Lay it down relaxed so it keeps its full density, otherwise that high-pressure joint is going to whistle like a train during startup.

Watch out

• Do not double-gasket both duct ends, stretch gasket to make it reach, or bolt over dirty, folded, missing, or displaced gasket.

Check

• Confirm gasket is installed on one duct/flange face only.
• Check corners first
• most gaps, folds, and rolled gasket start there.
• Keep the tape relaxed, not stretched thin.
• Clean and dry the flange face before gasket.
• If the joint is already tight over bad gasket, reopen it instead of burying it in mastic.

Steps

• Look for thin, shiny, stretched, or torn gasket sections.
• Check corners and end overlaps first.
• Remove bad tape instead of burying it under more sealer.
• Lay new tape relaxed in the flange track.
• Confirm the gasket is continuous before the lift.

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