What type of transverse connection is commonly used on smaller, light gauge ductwork?

The commonly used transverse connection on smaller, light gauge ductwork is the S and D connection. This method is popular because it offers simplicity and efficiency, particularly in lighter materials. The S and D connection involves using flanges made of sheet metal that are formed to interlock, creating a tight seal and allowing for easier assembly without the need for extensive tools.

This connection type is particularly advantageous in smaller duct systems because it minimizes weight and provides adequate strength. It is also easy to manufacture and install, making it a preferred choice in many HVAC applications where ductwork size is more manageable.

The other connection types, while effective, are typically better suited for larger or heavier gauge ductwork. TDC/TDF connections, for example, are more complex but offer robust joint integrity in larger systems. Pittsburgh connections involve folding the edges of the ductwork, which adds strength but may not be as practical in very lightweight setups. Button locks provide secure connections but are generally used in specific applications where structural integrity is critical. Thus, S and D connections stand out for their appropriateness for smaller, light gauge duct applications.