Apprentice question
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Verify before you commit. Cheap to catch now.
Use the fitting shape that keeps drainage moving. A bottom lip in a wet exhaust line can become a corrosion trap.
['A concentric reducer can create a dam at the bottom of a horizontal run. In humid exhaust or wash areas, that low pocket holds water and attacks seams.', 'Check flow direction, pitch, drain path, and whether the system should have an eccentric flat-bottom style fitting, drain detail, or revised route. Hold the change if it affects specified materials or listed exhaust construction.']