• Size

    18″ through 72″ OD

  • Spec

    ASTM A-53 Grade: A & B; A-135
A-252 Grade 1, 2, 3; API5L Grade A & B; and API5LX42 thru X-70

Double submerged arc welded pipe (DSAW) derives its name from the welding process wherein the welding arc is submerged in flux while the welding takes place. Both inside and outside welds are required and are usually accomplished in separate processes, hence the word “double.” These separate welds consume a portion of the other resulting in a single high quality weld nugget.

DSAW pipe is produced in sizes from 18″ through 72″ OD and wall thicknesses from .250″ through 1.5″.

Two different processes are used to manufacture DSAW pipe; the “Pyramid Rolls” method, and the “UOE” (U-ing, O-ing and Expanding) method. The difference in the processes is found only in the method of forming the cylinder. In the Pyramid Rolls process the cylinder is formed between 3 rolls arranged in a pyramidal fashion. The UOE method uses a “U” press, and “O″ press for forming the cylinder. The finishing and inspection processes are similar, and both methods use a flat steel plate as the raw material.

DSAW pipe may or may not be cold expanded. Cold expansion is a process where the pipe is expanded (up to 1.5%) to obtain its final OD dimension. In the process, a gain of yield strength results. Expansion is most often utilized in a UOE mill due to the need to recover yield strength lost during forming in the “O” press. DSAW pipe is available in the following grades: ASTM A134, A139, A252, A671, A672, A690, A691, CSA (Canadian) – Z245.1 and custom specifications. API 2B, 5LB, 5L X42 – 5L X80

DSAW pipe is normally produced in double random lengths with square ends or beveled ends. It is usually furnished bare but varnished pipe is also offered. A wide range of external coatings and internal linings are available with DSAW pipe.