200 litres of steel barrels of seam welding machine, its working principle belongs to the range of resistance welding: after the workpiece combination, through the electrode pressure, using the electric current flows through the joint resistance heat generated in the interface and its adjacent areas, thus forming a series of overlapping each other fusion nuclear and airtight weld. This equipment adopts welding method for seam welding, rolling wheel, cylinder was its width is greater than the plate lap part to control the thickness of the joint, welding electrode using high pressure when the welding current and continuous.