The Vanstone edge corresponds to which component in ductwork?

• A. The edge of a patented duct connector.
• B. A 180-degree bend (hem).
• C. The 90-degree flange on duct with companion flanges.
• D. The same as a draw-band joint.

Answer: (C)

The Vanstone edge is the edge prepared on a duct end to accept a bolted flange joint. It forms a 90-degree flange on the duct that mates with a companion flange, allowing two duct sections to be securely bolted together with a gasket for a seal. This makes it the 90-degree flange on duct with companion flanges, rather than a hem, a patented edge of a connector, or a draw-band joint.