Fusion weld
One process for producing pipe is Fusion Weld, sometimes called “Continuous Weld” and is produced in sizes 1/8” to 4-1/2”. Fusion Weld pipe begins as coiled steel of the required width and thickness for the size and weight of pipe to be made. Successive coils of steel are welded end to end to form a continuous ribbon of steel. The ribbon of steel is fed into a leveler and then into a gas furnace where it is heated to the required temperature for forming and fusing. The forming rolls at the end of the furnace shape the heated skelp into an oval.
The edges of the skelp are then firmly pressed together by rolls to obtain a forged weld. The heat of the skelp, combined with the pressure exerted by the rolls, form the weld. No metal is added into the operation. Final sizing rolls bring the pipe into its required dimensions.
