scope:

This standard sets performance requirements for ducts installed according to limitations and requirements specified for each individually manufactured duct system.

The fire performance of a duct depends in part on its ability to limit fire spread and on its ability to exhaust smoke in case of fire, if applicable. It is necessary to evaluate flame spread potential on the interior and exterior of the duct, and its structural integrity after fire exposure when used as a smoke exhaust system.

This standard is not intended to determine the suitability for all end use conditions of a product. Conditions under which a duct assembly is used vary widely. For example, ducts may be subjected to environments not represented by standard corrosion tests. This standard, therefore, does not evaluate the corrosion resistance in every environment where duct materials are used for handling corrosive fumes. It is the responsibility of the manufacturer to determine the suitability of the duct system for specific corrosive environments. The manufacturer should be consulted for recommended corrosive fume applications. Further, it is required that the manufacturer comply with all requirements of the ''Accepted Industry Practice for Industrial Duct Construction'' published by the Sheet Metal and Air Conditioning Contractors National Association, Inc. (SMACNA).

This standard evaluates ducts for their performance in regard to fire spread on the inner and outer surface of the duct and the suitability of the duct to be used for smoke removal. However, for ducts not intended for smoke removal in a fire situation (i.e., fume exhaust only) the exhausting capability of the duct is not evaluated.

This standard describes the minimum performance requirements for ducts that are intended for use in cleanroom facilities by evaluating the ability of the exterior surface to limit fire spread and smoke damage due to the contamination caused by products of combustion.

Purpose

This standard states Approval requirements for ducts used in exhausting noncombustible chemical fumes and corrosive vapors or noncombustible chemical fumes, corrosive vapors and smoke in fire situations.