The process characteristics of the pipe manufacturing machine

The main technological features of the straight seam steel pipe forming machine are reflected in the forming method, welding technology, and quality control. The following is a detailed analysis:
1. Main forming process characteristics
UOE forming method
It is completed in three steps: pre-bending → U-shaped press forming → O-shaped press forming, and finally cold expansion to eliminate stress.
The equipment is large but has a high level of automation, suitable for mass production, and can manufacture steel pipes with a wall thickness of up to 40mm.
The weld length is only half that of spiral welded pipes, with a low defect probability.
JCOE forming method
It is formed in stages by pressing into a J shape → C shape → O shape, and finally expansion (E).
The cost is lower than UOE, and the mold wear is small, suitable for small and medium batch production.
The forming quality is comparable to UOE, but the output is lower.
RBE forming method
It is formed by continuous three-roll bending and rolling, with uniform stress distribution.
The investment is small, and it is convenient to change specifications, but it is limited by pipe diameter and wall thickness.
2. Welding technology characteristics
Submerged arc welding: Using filler material and flux protection, the weld quality is stable, suitable for large-diameter steel pipes (up to 1500mm).
High-frequency welding: Utilizing the skin effect of the current, the welding speed is 15-45 meters/minute, suitable for thin-walled pipes.
Pre-welding + final welding: In the UOE process, pre-welding is done by gas protection welding first, and then final welding by submerged arc welding to ensure strength.
3. Quality control and equipment features
100% inspection: Including ultrasonic/ X-ray flaw detection to ensure no incomplete fusion, pores, etc. defects.
Expansion process: Both UOE and JCOE use cold expansion for size accuracy and strength improvement.
Intelligent control: The production line is equipped with a data acquisition system to achieve real-time parameter monitoring.
4. Application and limitations
Advantages: Straight seam pipes have good roundness and uniform pressure-bearing, suitable for fluid transportation; UOE/JCOE are suitable for thick-walled pipes, and high-frequency welding is suitable for thin-walled and irregular-shaped pipes.
Limitations: UOE equipment has a high investment, and RBE is limited by specifications.