Double Submerged Arc Weld (DSAW)
Definition - What does Double Submerged Arc Weld (DSAW) mean?
Double submerged arc welding is a process that involves two submerged arc welding passes. One pass of submerged arc welding takes place on one side of the material, and another pass takes place on the opposite side of the first pass.
Double submerged arc welding is advantageous over other pipe seam welding processes such as electric resistance welding because it can be used to form large diameter (4 inches and larger) and thick (1/4 inch and up) pipe. It also has high deposition rates and can easily makes welds with exceptional mechanical properties that can pass a variety of nondestructive examinations.
Corrosionpedia explains Double Submerged Arc Weld (DSAW)
Double submerged arc welding is a variant of the submerged arc welding process. The submerged arc welding process causes metal to coalesce through use of an electrical arc. The electrical arc is transmitted to the workpiece being welded through a consumable electrode. To prevent oxidation from occurring, the electrode and molten base material are protected from oxidation by a flux powder. When the flux powder is brought into contact with the heat from the electrical arc, it melts and resolidifies as slag.
Double submerged arc welding is commonly used in the oil and gas industry to make large diameter pipelines. These pipelines typically have either a straight, longitudinal double submerged arc weld or a spiral double submerged arc weld. Other industries that use the double submerged arc welding include any that involve the joining of thick plates, such as heavy equipment, mining, or infrastructure projects such as bridges.