Abstract: A corrosion-resistant volume damper apparatus for use in gas- and vapor-handling duct systems, installed between existing external duct flanges without having to custom cut or otherwise modify the duct system or the volume damper itself. The retrofittable volume damper has a housing or framework with an aperture extending therethrough and a corrosion-resistant damper blade having integral pivot arms. The aperture or bore is of a suitable size and shape to match the duct system within which the volume damper is to be installed. The housing preferably comprises a pair of corrosion-resistant plates of suitably rigid materials. The two plates have a series of through holes permitting the two plates to be bolted together with a damper blade to be rotatably sandwiched between the plates such that one of the pivot arms of the damper blade extends beyond the two plates on a plane perpendicular to, and away from, the axis of the bore.

Abstract: A corrosion-resistant test port kit is specially adapted to be retrofitted into existing duct work for use in testing or monitoring gases and vapors in an exhaust air transfer system that is designed to handle a wide range of potentially corrosive exhaust streams found in a wide variety of industrial applications. The apparatus provides the ability to install the test port kit in existing duct systems quickly and easily to monitor the gas stream without having to disassemble the duct system or interrupt its use for long periods.