Spiro-Loc Rigid Steel Duct

Spiro-loc is a light weight sheet metal tubing, which is machine made in a spiral form from metal strip coil stock. Forming dies are held for common sizes between 100 mm and 1500 mm diameter. Special dies can be produced for larger or non standard sizes.

The four-ply lock seam adds sufficient strength for the circular shape to be rigidly maintained up to 600 diameter in 0.95 mm material, or 500 diameter in lighter gauge. Additional rigidity and crushing strength can be achieved by the incorporation of one or two external swages. Common applications include ducting for heating, ventilating and air conditioning, void forming in concrete, irrigation pipe and rubbish shutes on high rise buildings.

Selection of Wall Thickness and Girth Joints The following table presents data which is acceptable under Australian Standard AS 4254-2002 ‘Ductwork for air-handling systems in buildings’.