Are metal band duct clamps required to be listed?

Metal band duct clamps are not required to be listed because they are generally classified as fittings in the mechanical code, which do not necessitate listing in certain applications. The code is more focused on the intended use of the clamp and its installation characteristics rather than requiring a specific listing for the metal band types used. This allows for flexibility and practicality in the installation process, as long as the clamps comply with the overall standards for performance and safety as dictated by the code.

On the technical side, listed products are typically those that have been tested for specific performance benchmarks and have a certification mark from an approved testing agency. For many duct applications, standard metal band clamps that meet performance criteria and are installed according to the guidelines set forth in the mechanical code do not need to be listed, thus confirming the appropriateness of using non-listed options for this purpose.