What is LSAW and SSAW Pipe?

LSAW and SSAW are variants of SAW (submerged arc welded) pipes. The difference between them is the way they are welded. In LSAW pipes, the welding is longitudinal, which means that steel (hot rolled coil plate) is rolled into a pipe and the seam is welded longitudinally. In the SSAW type, steel coils are welded spirally, like a helix, so that the coil (strip) assumes the shape of a pipe. SAW pipes are used mainly in oil and gas transportation. On the other hand, seamless (non-welded) pipes are mainly application in oil and gas exploration projects.

An LSAW pipe (“submerged arc welding”) is manufactured by cutting, bending, and welding steel plates (JCOE process). The two main types of LSAW pipes are the longitudinal (with a single or double straight seam weld, DSAW) and the spiral type (called, HSAW, SSAW or SAWL pipe).

Spiral steel pipes (SSAW Pipe) and straight seam steel pipes are currently widely used in water pipelines, construction and other industries, but there is a big difference between the two.

1. Different pressure-bearing capacity
The strength of spiral steel pipes is generally higher than that of straight seam steel pipes. The main production process is submerged arc welding. Spiral steel pipes can use blanks of the same width to produce steel pipes with different pipe diameters, and can also use narrower blanks to produce steel pipes with larger pipe diameters.

2. Different specifications
The specifications of spiral steel pipes are generally above 219mm, and most of them are of large diameter. The specifications of straight seam steel pipes are mostly of small diameter, but some manufacturers also have many large diameters.

3. Different prices

Spiral steel pipes are mostly settled by measuring rulers, and the price of straight seam steel pipes is mostly settled by weighing, but the price of spiral steel pipe is about 300 yuan/ton cheaper than that of straight seam steel pipe.

4. Different manufacturing processes

LSAW (Longitudinal Submerged Arc Welded)
It is made by welding steel plates longitudinally, and generally uses UOE, JCOE and other forming processes.
Features: straight seam welding.

SSAW (Spiral Submerged Arc Welded)
The hot rolled coil is welded after forming at a spiral angle, and the weld is distributed in a spiral shape.
Features: Spiral weld.

5. Different weld types

LSAW: Straight weld, along the axis of the pipe.
SSAW: Spiral weld, wrapped around the pipe at an oblique angle.

6. Different strengths and quality control

LSAW: Short weld, easy for flaw detection, more stable and reliable quality;
Suitable for high pressure, large diameter, key structure projects.

SSAW: Long welds with more potential weld defects;
Slightly lower strength than LSAW, but cheaper to manufacture.

7. Different application ranges

LSAW: Commonly used in high-demand situations such as long-distance high-pressure oil and gas transportation and structural support projects.

SSAW: Widely used in low-pressure fluid transportation, urban pipelines, infrastructure, etc.

Read more: Difference between Spiral Steel Pipe and LSAW Steel Pipe