The large-diameter spiral steel pipe factory employs numerous protective measures for spiral steel pipes during the winter.

Winter protection measures for large-diameter spiral steel pipe plants: Professional pipeline maintenance agents can be used to regularly clean, disinfect, and sterilize sewer pipes, ensuring unobstructed flow and preventing the pipes from becoming breeding grounds for pathogens. When cleaning pipelines, it is essential to use specialized pipeline maintenance products to effectively eliminate bacteria, neutralize odors, and prevent blockages. When selecting maintenance and unclogging products, prioritize safety and opt for those with high bactericidal efficacy that have been rigorously tested by reputable, authoritative institutions.

Currently, demagnetization of large-diameter spiral steel pipes typically employs a DC demagnetizing coil, which is connected downstream of the magnetic particle inspection machine. However, the demagnetization results often fail to meet customer requirements. The issue lies in the fact that the DC demagnetizing field generates only a reverse half‑cycle magnetic field, which can only partially counteract the residual magnetism inside the pipe, leaving the external residual flux within the specified limits—yet the effect remains unstable. As a result, while on‑site measurements may initially comply with specifications, the residual magnetism can exceed the allowable threshold after the pipe is moved or tapped.

For flaw detection in the welds of large-diameter spiral steel pipes, the most effective method is to employ pulsed‑echo ultrasonic testing. Since the primary objective is to determine whether defects are present, we use a scanning ultrasonic flaw detector. This instrument exploits the reflection characteristics of ultrasonic waves: on the display screen, the vertical axis represents the amplitude of the reflected echoes, while the horizontal axis indicates the travel time of the echoes. By analyzing the amplitude and timing of the defect‑related reflections, the size and location of the defect can be accurately assessed.

In terms of the specific raw materials used in their manufacture, large-diameter spiral steel pipes exhibit certain distinctive characteristics. Unlike conventional pipe materials, their defining feature lies in the hollow cross‑sectional design; this hollow structure results in a substantial internal surface area. Consequently, such pipes have seen widespread adoption in pipeline transportation applications. Endowed with numerous advantageous properties, they have earned significant recognition as a specialized material in the field of fluid conveyance.

During the production of large-diameter spiral steel pipes, edge misalignment frequently occurs, and numerous factors influence this phenomenon. In practical manufacturing, such misalignment often leads to grade downgrading of the pipe due to excessive dimensional deviations. Therefore, it is essential to analyze the causes of edge misalignment in small-diameter spiral steel pipes and to develop appropriate preventive measures. All welds—both the butt joints of the strip steel and the T‑joints where they intersect with the helical welds—are inspected by X‑ray fluoroscopy or radiography. Each pipe undergoes a hydrostatic pressure test, with pressure applied using radial sealing.

Structural steel pipes, including welded and seamless tubes, are particularly well suited for withstanding radial internal and external pressures. Large-diameter spiral-welded steel pipes, with their ideal annular cross-section, exhibit exceptional resistance to local buckling, making them among the most effective lightweight structural members. Steel pipes can be fabricated into fundamental elements such as columns and beams; they can serve as standalone structural components or be assembled into a wide variety of structural systems, including frames, trusses, and space frames.