Description
I. Core Production Processes and Classification
According to the welding process and application scenarios, straight seam welded pipes are mainly divided into two mainstream types: High-frequency Resistance Welding (ERW) and Submerged Arc Welding (LSAW). The production process is standardized and refined, ensuring highly controllable product quality.
1. High-frequency Resistance Welding Straight Seam Pipe (ERW)
Using steel strip coils as raw materials, relying on the skin effect and proximity effect of high-frequency current, the welding seam edges of the pipe are instantly heated and melted, and then seamlessly welded through mechanical pressure. No filler material is required throughout the process. The overall production speed is fast, the dimensional accuracy is high, the pipe wall is uniform, and the internal and external burrs can be precisely removed. It is the mainstream process for medium and small-sized diameter, thin-walled straight seam pipes. The production process mainly includes: steel coil unwinding → steel plate straightening → edge milling and trimming → rolling forming → high-frequency welding → internal and external deburring → cooling and shaping → sizing and straightening → cutting and finishing → flaw detection.
2. Straight Seam Submerged Arc Welding Pipe (LSAW)
Using a single thick steel plate as raw material, it is pressed into a tubular shape through UOE, RBE, JCOE, etc. forming processes, and formed using a double-sided submerged arc automatic welding process. The welding process has a large weld penetration, dense welds, and strong forming stability. This process is suitable for medium and large-sized diameter, thick-walled, high-pressure pipe production. The welding quality is higher, the pressure-bearing capacity is stronger, and it is mostly used in key projects and high-pressure fluid transportation scenarios.
II. Main Product Characteristics and Advantages
Compared with spiral welded pipes and ordinary seamless pipes, straight seam welded pipes have distinct comprehensive advantages and are suitable for most conventional and medium-high pressure scenarios:
- Stable structure, good pressure-bearing performance: A single longitudinal straight weld seam, the shortest weld length, low probability of welding defects, uniform force on the pipe circumference, excellent resistance to deformation and internal pressure, and overall structural stability far exceeds that of spiral welded pipes of the same specification.
- Precise dimensions, strong adaptability: High accuracy in pipe diameter, wall thickness, roundness, and pipe mouth is flat and regular, without obvious deformation, facilitating cutting, connection, and installation, and suitable for precise matching of pipe fittings, with high construction convenience.
- Excellent material quality, reliable performance: Mainly use high-quality carbon steels such as Q235B, Q345B, 20#, etc., with high mechanical strength and good toughness, possessing excellent pressure-bearing, wear resistance, and low-temperature resistance, capable of adapting to conventional outdoor and complex working environment scenarios.
- Outstanding cost performance: High production efficiency and high yield rate, compared to seamless pipes, the cost advantage is significant; compared to spiral welded pipes, the weld quality is more stable, the detection difficulty is lower, and the overall engineering cost performance is higher.
- Strong capability： Supports secondary processing such as hot-dip galvanizing， anti-corrosion coating， bevel processing， bending， drilling， etc.， and can customize special processes such as anti-corrosion， wear resistance， and rust prevention， suitable for diverse engineering needs.
