Before performing the actual welding process, several critical steps must be taken to ensure the quality and integrity of the welded steel pipe. Pre-welding preparation is crucial for achieving optimal results, minimizing defects, and ensuring the safety and durability of the final product. Below are key factors to consider during the pre-welding stage:
Joint Alignment:
The joint, also known as the forming seam, must have no misalignment, or the misalignment should be within the specified limits. Generally, the allowable amount of misalignment is ≤ 8% of the plate thickness, with a maximum value not exceeding 1.5mm.
Penetration and Deposition Control:
It is essential to ensure that the weld seam has the appropriate penetration depth and deposition volume. This helps prevent issues such as cracking or burn-through after welding. Additionally, controlling the height of the weld seam is necessary to avoid affecting the reinforcement of the external weld.
Continuous Weld Bead:
The weld bead must be continuous and properly formed to facilitate subsequent external welding. This ensures a smoother welding process and strengthens the joint.
Absence of Defects:
The weld seam should be free from defects such as welding deviation, porosity, cracks, slag inclusions, burn-through, or back welding bumps. Furthermore, the center deviation of the weld seam must be controlled within a tolerance of ≤1mm.
No Arc Burns or Spatter:
During the pre-welding process, there should be no arc burns, minimal spatter, and no impact on the bevel and surface of the pipe end. This helps maintain the integrity and appearance of the pipe.
Weld Seam Matching:
The weld seam should match the base metal, ensuring that the physical and chemical properties of the weld metal meet the required standards. This guarantees that the final welded structure will have the necessary strength and durability for its intended application.
By following these pre-welding guidelines, manufacturers can produce welded pipes with higher quality, fewer defects, and better long-term performance.
United Steel Industry As the most important steel pipe manufacturer and exporter in China, in the past 20 years, we have completed more than 100 projects, with partners in more than 100 countries, and established relationships with oil and gas and EPC companies in many countries business relationship.
For more information about the product price, catalog and rolling mill inspection certificate,
please consult:Email:Sales@usisteels.com
