Do I put the butyl gasket tape on the inside or outside of the bolt holes on a TDC 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.
Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.
Steps
Always run the butyl gasket tape on the inside of the bolt holes, tracking directly along the center point of the mating flange faces. This ensures the air pressure pushes the gasket...
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do i put the butyl gasket tape on the inside or outside of the bolt holes on a tdc flange?