What are the production equipment for spiral welded steel pipes?

With the development of the construction industry, the application of spiral welded steel pipes (SSAW) is becoming increasingly widespread. Their excellent pressure-bearing capacity and economy make them the first choice for many engineering projects. After anti-corrosion treatment, spiral welded steel pipes also possess excellent corrosion resistance. Various equipment is required in the production process of spiral welded steel pipes. The following are some common spiral welded steel pipe production equipment:

1. Spiral Forming Machine
The spiral forming machine is the core equipment in the production of spiral welded steel pipes. It uses multiple forming rollers to gradually extrude and curl the strip steel into a spiral cylindrical shape, thus forming the basic shape of the steel pipe. Currently, common forming machine types include three-roll forming machines and four-roll forming machines; the more rollers, the higher the forming accuracy.

2. Milling Machine
The milling machine is used to mill the edges of the steel strip on both sides to form the required bevel shape (such as I-type, V-type, X-type) to ensure sufficient weld penetration and good forming during welding. Precise milling is a prerequisite for ensuring weld quality.

3. Submerged Arc Welding Machine
Submerged arc welding machines are used to weld the formed spiral joints, typically involving two processes: internal welding and external welding. Submerged arc welding offers advantages such as high welding speed, deep penetration, and stable weld quality, making it a core welding equipment in spiral welded pipe production.

4. Straightening Machine
Straightening machines are used to straighten the welded spiral steel pipes as a whole. Multiple sets of staggered straightening rollers are used to gradually roll and eliminate bending and twisting generated during forming and welding, ensuring the straightness of the steel pipe meets standard requirements.

5. Flying Shear Machine (Short-Length Cutting Device)
Flying shear machines are used to cut continuously produced spiral steel pipes to a set length. It can complete the cutting while the steel pipe is continuously moving, ensuring a clean cut and precise length, making it a key piece of equipment for improving production efficiency and yield.

6. Anti-corrosion Coating Line
To improve the corrosion resistance of spiral steel pipes, anti-corrosion materials are usually coated on the inner and outer surfaces of the pipe. The anti-corrosion coating line includes external coating equipment (such as 3PE, FBE) and internal coating equipment (such as cement mortar, liquid epoxy). The coating line can evenly cover the surface of the steel pipe, significantly extending the service life of the pipeline.

7. Auxiliary Equipment
In addition to the main equipment mentioned above, the spiral welded pipe production line is also equipped with various auxiliary equipment, including:

● Uncoiling machine: Unwinds the strip steel;
● Leveling machine: Eliminates the original deformation of the strip steel;
● Non-destructive testing equipment: Uses ultrasonic or X-ray to detect weld defects;
● Hydrostatic testing machine: Verifies the pressure-bearing capacity of the steel pipe;
● Pipe end processing equipment: Beveling and chamfering.

Conclusion: 

The production of spiral welded steel pipes is a complex system engineering project involving the coordinated operation of multiple pieces of equipment. The close cooperation of spiral forming machines, milling machines, submerged arc welding machines, straightening machines, flying shear machines, anti-corrosion coating lines, and various auxiliary equipment ensures the manufacturing quality and production efficiency of spiral welded pipes.

Read more: Process Performance of SSAW Steel Pipe or Seamless vs. Welded Pipe