Process Characteristics of Spiral Tubes

　　 Spiral tube The raw materials used in production are steel coils, welding wire, and flux. Before being put into service, these materials must undergo rigorous physical and chemical testing. At the enterprise, steel coil ends are joined using single‑wire or dual‑wire submerged arc welding; during the post‑welding process after rolling into steel pipes, a fully automated submerged arc welding system is employed. Prior to forming, the strip undergoes leveling, edge trimming, edge planing, surface cleaning, and bending. An electrical safety pressure gauge is used to regulate the pressure of the cylinders on both sides of the conveyor, ensuring smooth and stable material transport.

　　External or internal controlled roll forming is employed. A weld‑gap control system is utilized to ensure that the weld gap meets the specific requirements of the welding process, with strict management of pipe diameter, misalignment, and weld‑gap dimensions. Both internal and external welds must be performed using Lincoln equipment, employing either single‑wire or dual‑wire submerged arc welding to achieve consistent weld quality. All weld seams are inspected online by a continuous ultrasonic automated flaw detector, guaranteeing 100% nondestructive testing coverage of the spiral welds. Any detected defects trigger an automatic alarm and are marked with spray‑on identifiers, enabling production personnel to promptly adjust process parameters and eliminate defects.

　　Steel pipes are cut into individual lengths using an air plasma cutter. After each batch of steel pipes is cut into single‑length sections, they undergo a rigorous first‑article inspection to verify the mechanical properties of the welds, the chemical composition, the metallurgical condition, and the surface quality of the steel‑concrete composite. Nondestructive testing is also performed to ensure that the pipe‑fabrication process meets all specifications before the pipes are approved for full‑scale production.

　　At locations on welds marked for continuous ultrasonic testing, manual ultrasonic and X-ray inspections shall be performed. If defects are detected, they must be repaired and then re‑examined using nondestructive evaluation techniques until it is confirmed that the defects have been eliminated. For strip steel butt welds, as well as for pipe sections where D‑shaped joints intersect with spiral welds, X‑ray fluoroscopy or radiographic film inspection shall be conducted. Each steel pipe shall undergo a hydrostatic pressure test, with the pressure applied to achieve radial sealing. The test pressure and duration must be strictly managed and controlled by the microcomputer‑controlled pipe hydrostatic testing system.

　　Spiral pipes are primarily used in water supply systems, the petrochemical and chemical industries, power generation, agricultural irrigation, and urban infrastructure development. Applications include fluid conveyance—such as potable water and wastewater—and the transportation of natural gas, steam, and liquefied petroleum gas. Structural applications encompass pile casings, bridge construction, wharves, roadways, and various building structures.

　　During the study of spiral pipe forming, the steel plate exhibits uniform deformation temperature, low residual stress, and a scratch-free surface. The fabricated spiral pipes offer significant flexibility in terms of diameter and wall thickness, particularly when producing high-grade thick-walled pipes—especially medium- and small-diameter thick-walled pipes—providing advantages unmatched by other processes and meeting diverse customer requirements. There are numerous specifications required for spiral pipes.

　　Advanced double-sided submerged arc welding technology enables enterprises to achieve optimal welding positions, thereby minimizing issues such as edge misalignment, weld deviations, and defects, and facilitating effective control over weld quality. To ensure thorough inspection and monitoring of the entire steel pipe production process, 100% quality checks are conducted on all pipes, effectively guaranteeing product quality. All equipment along the production line is equipped with connectivity to a computer-based data acquisition system, enabling real-time data transmission.