ComifoWhisper-Loc Seam Closer,seaming machine,Standing Seam Machine,whisper-loc seam closing,seam closing machine General three different seams are common in the industry to connect the corners of the ducts: button lock seam, Pittsburgh seam and Duct seam. Button snap lock and Pittsburgh lock can be produced on the Comifo lock forming machines. The Pittsburgh seam shows much better results and can also be used for a higher pressure.Whisper-Loc Seam Closer are available in the horizontal or vertical and close pittsburgh seams. Pittsburgh joint is commonly used to join the seams of metal ducts. Seam closing has traditionally been accomplished by manually hammering the margin of the seam against the duct wall (peening). Disadvantages of such peening include the time required and the almost intolerable noise produced. The latest design in seaming technology is now available. At the Pittsburgh joint, the individual seams are called Pittsburgh seam(pittsburgh lock) and standing seam(right angle flange). On a Pittsburgh joint, the operator pushes the standing seam into the Pittsburgh seam, fastens them to each other and closes the joint on a seam machine. Model No. Style Thickness Range Duct Length SpeedVWSC-1300 Vertical 0.4-1.2mm18-30 Ga1000-1250mm 24m/min (78FPM) VWSC-1600 1000-1550mm HWSC-1300 Horizontal 910mm, 1130mm, 1160mm HWSC-1600 1130mm, 1160mm, 1440mm More Detailed Pictures: