Plain spigots are used where the damper unit is to be attached to spiral, circular or ductwork of sizes below that of the certified parameters.
The plain spigots are 50 mm wide which has the effect of increasing the damper insertion depth to 400 mm on a 300 mm deep damper and similarly to 300 mm deep on a 200 mm deep damper. A fire retardant gasket must be inserted between the damper casing and the spigot connection to ensure that no leakage through the joint occurs.
The flanged spigots can be manufactured in Grades 316 and 304 Stainless Steel and Mill Galvanised Mild Steel. Where Mill Galvanised Mild Steel is used all welds and cut edges are treated with two coats of zinc rich paint after manufacture. The spigot band sizes can be to the Flamgard Calidair standard 50mm or to the clients special band details.