Key factors determining the quality of spiral welded pipes

Spiral welded pipes (SSAW), commonly known as spiral steel pipes, are extensively utilized across various industries. These pipes are manufactured by extrusion welding of steel strip coils. Smaller diameter pipes are typically produced using high-frequency welding, while larger diameter pipes are made with double-sided submerged arc welding. High-frequency welding technology enhances both efficiency and product quality during the manufacturing process of these welded pipes (ERW). What is the key to determining the quality of spiral welded pipes? Read on to learn more.

Key Factors Determining the Quality of Spiral Welded Pipes

- Strict Adherence to Production Standards:

Ensuring quality involves strictly following production standards, with 100% X-ray inspection of welds to verify that the mechanical properties and chemical composition meet the required standards. High-frequency welding is used to heat the workpiece to the necessary temperature, creating a uniform metal molten pool that results in a stable weld. This method is suitable for both large and small diameter pipes, offering precise control over the heating and weld quality.

- Automatic Double-Wire Double-Sided Submerged Arc Welding:

This advanced welding process enhances efficiency by reducing the number of welding passes required. It is widely adopted in production due to its ability to address potential defects in manual welding, making it a preferred choice in industries like construction and building decoration.

- Pre-Forming and Heating:

The tube blank must be properly chamfered and heated to a high temperature before forming, ensuring uniform distribution of spiral welds and misaligned edges. Heating the tube blanks directly in a furnace without preheating maximizes material utilization.

- Post-Welding Stress Management:

After welding, annular brackets are attached to both ends of the pipe section to disperse stress in the weld area. This helps reduce the residual stress and plastic deformation often observed in spiral welded pipes compared to straight seam welded pipes, improving their bending performance.

- Manual Arc Welding for Large-Diameter Pipes:

For large-diameter tube blanks, manual or electric arc welding is used to ensure full penetration of the heat-affected zone. The welding current is carefully controlled to ensure even distribution, preventing defects like cracking and ensuring consistent weld quality.

These measures collectively ensure the high quality and performance of spiral welded pipes across various applications, addressing challenges such as stress distribution, weld uniformity, and material efficiency during production.