ERW (Electric Resistance Welded) pipe is a type of steel pipe produced using the ERW manufacturing process. Here is an overview of the ERW pipe manufacturing process:
Coil Preparation: The process starts with preparing steel coils of the desired width and thickness. These coils are typically made from hot-rolled steel.
Uncoiling: The steel coil is fed into the uncoiler machine, which gradually unwinds the coil, allowing it to pass through the subsequent stages.
Strip Edge Milling: The edges of the strip are milled or trimmed to remove any irregularities and ensure smooth, squared edges.
Forming: The strip is passed through a series of rollers that gradually shape it into a cylindrical tube. The edges of the strip are brought together to form a longitudinal seam.
High-Frequency Induction Welding: As the strip edges come together, they are heated using high-frequency induction currents. The heat generated by resistance to the electric current fuses the edges together to form a solid weld.
Sizing: After welding, the tube passes through a series of sizing rolls that give it its final dimensions and ensure proper roundness and wall thickness.
Cutting: The continuous tube is then cut into individual pipe lengths according to the required specifications.
Straightening and End Facing: The cut pipes go through straightening machines to remove any residual stresses and ensure straightness. The ends are faced to achieve precise perpendicularity and clean surfaces.
Hydrostatic Testing: Some ERW pipes undergo hydrostatic testing to check their strength and leakage resistance. Water or another test fluid is pumped into the pipes under pressure while they are sealed at both ends.
Final Inspection and Coating: The pipes undergo a final inspection for dimensional accuracy, surface quality, and other specified requirements. They may also receive various protective coatings or treatments as per customer specifications.
Storage and Transportation: The finished ERW pipes are stored, bundled, and prepared for transportation to their intended destinations.
The specific details of the manufacturing process may vary depending on the pipe size, grade of steel, and applicable standards. The above steps provide a general overview of the ERW pipe manufacturing process.