Definitions Category: Seams

Snaplock seams use a male side with a button punch at 2″ intervals and a female side with a hemmed pocket that when joined create a solid and reliable longitudinal seam on ductwork and fittings up to +-4″ of pressure. Screws required at both ends of duct at 4″ pressure, as well as on 3″ pressure when width is larger than 48″.

Snaplock seam for coil line duct assembled in the factory.

Small Pittsburgh seams use a male flange and a female pocket of 1/4″ with tab that after the male end is inserted is pounded over the top to ensure a secure longitudinal seam. Pittsburgh seams are approved for +/-10″ of pressure.

Pittsburgh seam for coil line duct assembled in the factory.

Large Pittsburgh seams use a male flange and a female pocket of 5/8″ with tab that after the male end is inserted is pounded over the top to ensure a secure longitudinal seam. Pittsburgh seams are approved for +/-10″ of pressure.

Wire feed welding joins metal by heating the piece and a continusously fed filler metal electrode with an electric arc. The filler metal serves as both heat source and filler metal for the welding point.

Tig welding uses heat generated by an electric arc struck between a consumable tungsten electrode and the piece to fuse metal in the joint area and produce a molten weld pool joining without filler.