Hydraulic seam closing machine can be usedwith duct forming line, TDF roll formingmachine, and Pittsburgh lock machine. Theideal duct connection includes a united jointand the right-angle side works out seams ofhigh quality without the help of anotherauxiliary connecting tool. The process doesnothing to hurt the surface of the workpiecewith low noise.The finished seam is close,even, and effective. Plates in differentthicknesses are workable and can be finishedquickly and safely.