Straight Seam Welded Pipe

Straight seam welded pipe, is a kind of pipe with welded seam longitudinally parallel to the steel pipe, it is made by rolling up hot-rolled or cold-rolled steel coil to form a round steel pipe then weld together using the welding equipment. (It is known as the straight seam line). Straight seam welded pipe production process is of simplicity, high production, efficiency and low cost. According to the production process, straight seam steel pipe can be divided into high-frequency straight seam steel pipe (ERW pipe) and submerged arc straight seam steel pipe (LSAW pipe). Straight seam steel pipe is mainly used in water works, electricity, agricultural irrigation, urban construction for conveying of gas, steam, liquefied petroleum gas etc.

Straight Seam Welded Pipe

Straight Seam Welded Pipe

Straight seam welded pipe is a type of steel pipe manufactured by bending a steel plate or strip into a tubular shape and then welding along the longitudinal direction, with the weld seam appearing in a straight line, hence its name. It is one of the widely used pipes in the industrial field, playing an important role in various industries due to its simple production process and relatively low cost.

I. Production Process

The production process of straight seam welded pipe mainly includes the following steps:

Raw material preparation: Select hot-rolled or cold-rolled steel plates and strips that meet the requirements, and perform pre-treatment such as cutting and derusting.

Forming: Continuously bend the steel plate/strip into a tubular shape using a forming machine to ensure the roundness and dimensional accuracy of the pipe blank.

Welding: Adopt welding processes such as high-frequency resistance welding (ERW) and submerged arc welding (SAW) to weld the longitudinal seam of the pipe blank, forming a complete tubular structure.

Finishing: After welding, perform processes such as sizing, straightening, and pipe cutting. Some products also require subsequent processing, such as flaw detection, heat treatment, or anti-corrosion coating, to ensure quality.

II. Main Characteristics

Weld seam feature: The weld seam is distributed in a straight line along the length of the steel pipe, which is significantly different from the spiral weld seam of spiral welded pipes.

Production efficiency: The forming and welding processes are relatively simple, suitable for mass and continuous production, with high production efficiency.

Cost advantage: The utilization rate of raw materials is high, and the processing flow is short, resulting in a lower cost compared to seamless steel pipes.

Specification limitations: Due to the limitations of the forming process, it is more challenging to produce large-diameter and thick-walled straight seam welded pipes, resulting in a relatively limited specification range.

III. Application Fields

Due to their high cost performance, straight seam welded pipes are widely used in various fields:

Water supply and drainage engineering: Used for transporting tap water, sewage, etc., usually requiring anti-corrosion treatment.

Gas transmission: Suitable for low-pressure gas pipelines, with strict requirements on the quality of the weld seam.

Steel structure manufacturing: Used as components such as supports and columns in buildings like factories and bridges.

Mechanical manufacturing: Can be used as raw materials for parts, which are processed and then used in equipment assembly.

Straight seam welded pipes occupy an important position in industrial and civil fields. Their performance and application scenarios are closely related to the production process. When selecting, factors such as specifications, material, and weld seam quality should be comprehensively considered according to specific needs.