Apprentice question
Field check
Standard work. Do it right, keep moving.
Metal-to-metal sleeve joints leak. Pull the flange, clean the faces, add the approved gasket/sealant detail, and re-tighten evenly.
['A duct flange bolted to a louver sleeve can look solid but still leak if the gasket is missing. Under fan pressure, the gap becomes a whistle.', 'Verify the joint face, gasket, fastener spacing, and sleeve alignment. The recovery is to unbolt the joint enough to clean it, install the approved butyl/neoprene gasket or sealant system, then tighten evenly without twisting the sleeve.']