What is SSAW steel pipe?

What is SSAW steel pipe?


SSAW steel Pipe (Spiral Submerged arc-welded Pipe) is a kind of steel pipe made by coiled steel plates into billets in a spiral shape and Welded by double-sided Submerged Arc welding technology. The Angle of spiral welding makes the weld of the pipe spiral distribution, uniform distribution, which is conducive to withstand greater internal and external pressure.

SSAW steel pipe production process

The production of spiral submerged arc welded pipe is divided into the following main steps:
Uncoiling and straightening: the steel coil is unrolled and straightened to make it flat without bending.
Edge milling: The edge of the steel plate is finished to ensure that the welding edge is smooth and smooth.
Centring welding: the steel coil joint is partially welded to ensure continuous production.
Pre-bending and forming: The edge of the steel plate is pre-bent, and then the steel plate is rolled into a spiral tube blank by the forming machine.
Spot welding: Initial fixing of the joint of the steel plate.
Internal and external submerged arc welding: The submerged arc welding technology is used to weld the weld inside and outside the pipe to form a continuous weld.
Cutting and dressing: the steel pipe is cut according to the required length and the end is trimmed (expanding, chamfering, etc.).
Detection:
Ultrasonic inspection and X-ray inspection: ensure that the weld is free of defects.
Hydraulic test: verify the pressure resistance and tightness of the steel pipe.
Coating and labeling: anticorrosive coating is treated according to requirements, and specifications, batch and other information are marked.

SSAW steel pipe features

High production efficiency:
Spiral forming and welding at the same time, high production efficiency, suitable for large diameter pipe manufacturing.

Strong flexibility:
By adjusting the spiral Angle, a larger diameter range of steel pipes can be produced, especially for large diameter steel pipes (common diameter of 1200mm or more).

Lower cost:
Using steel plate as raw material, compared with seamless steel pipe, the production cost is lower.

High strength and sealing:
The spiral weld is evenly distributed, can effectively disperse external force, and the welding quality is stable.

Long weld length:

Spiral welds are longer than straight seam welded pipe (LSAW), there are more welding points, and the quality of the weld is more dependent on process control.

The main uses of SSAW steel pipe

Transportation pipeline:
Often used to transport oil, natural gas, water and other media.
Structural pipe:
Used for bridge, wharf, road construction and other structural support.

Power and Chemical equipment:
Used in the manufacture of pipeline support structures and anti-corrosion devices.

Municipal construction:
Used for water supply and drainage, sewage treatment system pipe network.

Comparison with other welded steel pipes

SSAW vs. Straight submerged Arc Welded Pipe (LSAW) :
Weld direction: SSAW is spiral weld with long weld length; LSAW is a straight seam weld with a short weld length.
Use: LSAW is more suitable for high strength, high pressure demand occasions, such as oil pipelines, SSAW is suitable for long distance medium and low pressure transportation.
Cost: SSAW has higher production efficiency and lower cost; LSAW has high cost due to complex process.

SSAW vs. Resistance Welded Pipe (ERW) :
Size range: SSAW is suitable for large diameter steel pipe; ERW is mainly used for small diameter steel pipes.
Welding process: SSAW adopts submerged arc welding, with high weld quality; ERW adopts resistance welding and is suitable for thin-walled pipe production.
Application scenario: ERW steel pipe is mostly used for low pressure pipes and structural parts, while SSAW is mostly used for medium and large caliber conveying and engineering structures.

Contrast with seamless steel pipe

Manufacturing process:
Seamless steel pipe is processed by the whole billet, no weld, good integrity; SSAW is manufactured by rolling plate welding and has welds.

Features:
Seamless steel pipe has higher pressure resistance and corrosion resistance, more suitable for high temperature and high pressure environment; SSAW is more suitable for long distance transport and low pressure environments.

Cost:
The manufacturing of seamless steel pipe is difficult and the cost is high. SSAW steel pipe production process is simple, low cost.

Size range:
The seamless steel pipe is mostly small and medium-sized diameter pipe, the maximum diameter is limited; SSAW can produce large diameter steel pipes.

Typical applications:
Seamless steel pipes are often used in high-pressure boilers, chemical equipment and other high-demand scenarios; SSAW is used for long-distance oil and gas pipelines and municipal construction.

Conclusion:

Spiral submerged arc welded pipe (SSAW) is a kind of large diameter welded steel pipe with high cost performance and high flexibility. It is widely used in conveying fluids, building structures, and municipal engineering. Compared with other welded steel pipes, SSAW is more suitable for long-distance pipeline transportation; Compared with seamless steel pipes, although the performance is slightly inferior, it has more advantages in terms of cost and manufacturing efficiency. SSAW is one of the essential materials in industry.

read more: What are the major advantages of welded steel pipes? or Types of welded steel pipes