Spiral Welded Steel Pipes High-Capacity Steel Pipe Solutions for Natural Gas, Potable Water, Wastewater & Deep Well Projects ???? Product Description Spiral welded steel pipes are manufactured by forming hot-rolled steel coils into a spiral shape. The edges are joined using submerged arc welding (SAW) on both the inner and outer surfaces. Throughout the production line, the edges are opened, formed, welded, and tested with 100% ultrasonic inspection to detect any weld flaws.