SSAW pipe meaning

SSAW (Spiral Submerged Arc Welded) steel pipe is a kind of large-diameter and high-strength welded pipe made by rolling the steel strip at a specific spiral Angle and applying Submerged arc welding technology at the spiral seam. This process is widely applied in multiple fields such as water supply and drainage, municipal construction, oil and gas transportation, and structural support due to its flexibility and high metal utilization rate.

Compared with LSAW steel pipes, SSAW steel pipes (spiral steel pipes) have a shorter production cycle and are more economical in cost. However, due to its relatively low welding quality, SSAW steel pipes are usually not suitable for environments that can withstand high temperatures and pressures. This type of steel pipe is widely used in the field of water transportation, such as in the cooling water system of power stations. For those systems that require large capacity and can operate under low pressure conditions, spiral welded pipes are a suitable choice.

The manufacturing process of SSAW steel pipes

Uncoiling and leveling: Unroll large-sized steel coils, and use a leveling machine to remove internal stress and slight bending to ensure the flatness of the steel strip.
Spiral winding: The steel strip is continuously wound into a spiral tube blank at the designed spiral Angle (usually 45° - 60°). According to the width of the steel strip, the pipe diameter can be flexibly adjusted without changing the mold.
Submerged arc welding: Sprinkle granular flux at the spiral joint of the tube blank and use double-wire or multi-wire double-sided automatic submerged arc welding equipment for welding. The arc burns stably beneath the flux layer, fusing the edges into a dense weld seam. The spiral welds are evenly distributed around the pipe body, which helps to disperse the circumferential stress and thereby enhance the pressure-bearing capacity.
Straightening and sizing: After welding, the tube blank is cold straightened by a straightening machine or a hydraulic pipe expander to eliminate deformation and ensure that the dimensional tolerances such as outer diameter and ellipticity meet the standard (diameter tolerance is usually ≤ 0.12%, ellipticity ≤ 1%).
Inspection and processing: Conduct ultrasonic, X-ray, magnetic particle or penetrant tests on spiral welds and pipe bodies to ensure that 100% of the welds are qualified. Depending on different usage environments, various anti-corrosion coatings such as bare pipe, light oil anti-rust, sandblasting primer, epoxy powder (FBE), and three-layer polyethylene (3PE) can be selected.

Main features

Continuous and highly efficient production: Online roll forming is possible, cutting loss is significantly reduced, and metal utilization is increased to  6 %  -  8 %.
The equipment investment is economical and flexible to move: Equipped with a trailer-mounted device, it can be directly produced on the construction site, effectively saving logistics and inventory costs.
Balanced mechanical properties: The spiral weld effectively disperses the stress concentration points and has excellent pressure resistance and impact resistance.
Wide application range: Adaptable to various complex terrains and on-site construction requirements, it is particularly suitable for municipal water supply and drainage, farmland irrigation, and temporary pipeline projects.
Easy to achieve automation: The production process is stable, and the weld seam tracking and inspection technology can be highly automated.

Application field

Water supply and drainage engineering: covering urban water supply, sewage treatment, rainwater discharge, etc.
Oil and gas pipelines: Suitable for onshore and offshore transportation pipelines, especially for low to medium pressure systems.
Agricultural irrigation: It is suitable for temporary water conveyance pipelines in the field, facilitating rapid on-site laying.
Structure and pile driving: Suitable for wharves, Bridges, and building pile pipes, it has both load-bearing and transportation functions.

Combining spiral winding technology and multi-wire submerged arc welding process, SSAW pipes not only meet the diverse requirements of diameters and pressure grades, but also achieve efficient and low-cost mass production. It has become an indispensable pipe material choice in municipal construction, water conservancy projects and the fields of oil and gas transportation.