| 摘要 |
<p>In winding a continuous strip of sheet metal having chamfered edges into a helical seam pipe, the chamfered edges define an inside seam and an outside seam in the pipe. Initially, after forming the pipe, a tack weld is formed in the outside seam and then a finish weld is provided in the inside seam. Next, the pipe is cut into lengths and finally a finish weld is made in the previously tack welded outside seam. The cross sectional area of the inside seam is kept to a minimum and though different thicknesses of strip can be used for forming the pipe, the cross sectional area of the inside seam is maintained a constant over the range of strip thicknesses used to assure that the inside seam is finish welded in as short a time as possible with the pipe moving axially at the highest possible speed.</p> |
