WHAT IS HSAW (SSAW) PIPE?

HSAW stands for Helical Submerged Arc Welding. In the steel pipe industry, it is also widely referred to as SSAW (Spiral Submerged Arc Welding). Both acronyms describe the exact same manufacturing process.

Unlike LSAW pipe which has a single straight seam, HSAW pipe features a weld seam that wraps around the cylinder like a helix or a spiral staircase. It is a highly cost-effective method for producing extremely large diameter pipe for water transmission, deep foundation piling, and structural casing.

How is HSAW Pipe Manufactured?

The primary difference between HSAW and other heavy-wall pipes is the raw material. While LSAW is made from individual steel plates, HSAW is continuously manufactured from massive coils of hot-rolled steel.

• 1. Uncoiling & LevelingThe heavy steel coil is unwound, flattened through a series of leveling rollers, and the edges are milled to prepare them for welding.
• 2. Spiral FormingThe flat steel strip is fed into a specialized forming machine at a specific angle (the forming angle). By simply changing this feed angle, the mill can produce different outside diameters (OD) from the exact same width of steel coil.
• 3. Double Submerged Arc WeldingAs the edges meet to form the spiral, they are tack-welded and then permanently fused using the Submerged Arc Welding process. Just like DSAW, it is welded from both the inside and the outside under a protective layer of granular flux to ensure 100% weld penetration.
• 4. Cutting & TestingThe continuously forming pipe is cut to the requested length (often 20ft, 40ft, 60ft, or custom lengths up to 80ft+) using a plasma cutter that travels with the pipe. It then undergoes rigorous ultrasonic and hydrostatic testing.

The HSAW Advantage