What is the Spiral Welded Pipe Spiral welded pipe(SSAW pipe, also called HSAW pipe). The pipe is formed by spiral submerged arc welding technology. Spiral welded pipes are formed using narrower plates or hot rolled coils, which lowers their production costs significantly. The welding line is shaped like a helix. The spiral welding process permits the production of large-diameter pipes suitable for transporting large volumes of oil and gas. Some SSAW pipes were historically limited to low-pressure applications.