Different properties
1. High-frequency welded steel pipe: After hot-rolled coil is formed in a forming machine, the skin effect and proximity effect of high-frequency current are used to heat and melt the edges of the tube. Pressure welding is then performed under the action of squeeze rollers to produce the product.
2. Straight seam welded steel pipe: including double-sided submerged arc welded straight seam welded steel pipe and high-frequency resistance welding. The English abbreviation of high-frequency resistance welding is ERW. Submerged arc welded straight seam steel pipe is divided into UOE, RBE, and JCOE steel pipe according to its different forming methods.

Different Materials
1. High-Frequency Welded Steel Pipe: High-frequency resistance welded steel pipe uses a different welding process than conventional welded pipe. The weld seam is formed by melting the base metal of the steel strip, resulting in greater mechanical strength than conventional welded pipe.
2. Straight seam welded steel pipe: The materials of straight seam welded steel pipe mainly include Q195, Q215, Q345, and X42 pipeline steel series. According to the specified wall thickness, straight seam welded steel pipes are divided into ordinary steel pipes and thickened steel pipes. According to the form of the pipe ends, steel pipes are divided into threaded and non-threaded types.

Different Features
1. High-frequency welded steel pipe: Smooth surface, high precision, low cost, and minimal weld height, making it suitable for 3PE anti-corrosion coating. High-Frequency Welded Steel Pipes differ significantly from Submerged Arc Welded Pipes in welding methods. Since welding is completed instantly at high speed, the difficulty of ensuring welding quality is much higher than that of submerged arc welding.
2. Straight seam welded steel pipe: The length of straight seam welded steel pipe is mainly divided into fixed length and variable length, which is mainly based on customer requirements. The length is generally 6-14 meters. Large-diameter straight seam welded steel pipe may require two steel plates for rolling, which also forms a double weld.

This layer, applied around the exterior of a pipeline to provide insulation and heat insulation, generally consists of the following components:
1. Anticorrosion Layer: Two coats of anti-rust paint are applied to the outer surface of the pipeline.
2. Thermal Insulation Layer: A layer of thermal insulation and heat-insulating material;
3. Moisture-Proof Layer: This layer prevents moisture from entering the thermal insulation layer. Typically, this layer is wrapped with felt and has asphalt mastic applied to the seams. This layer is typically used for cold pipes.
4. Protective Layer: This layer protects the thermal insulation layer from damage. Typically, this layer is made of glass cloth wrapped around the protective layer.
5. Coloring Layer: This layer is painted a specific color to distinguish the fluid within the pipeline.
The purpose of corrosion protection is to isolate the metal surface of the pipeline from the corrosive environment, extend the life of the pipeline, and prevent leakage; reduce the heat loss of the medium in the pipeline (such as steam, hot water), or reduce the external heat transfer to the low-temperature medium (such as chilled water); maintain the medium temperature to meet process requirements or prevent the medium from solidifying.

Unequal-leg angle steel is a steel material with a right-angled L-shaped cross-section and unequal sides. It is a type of angle steel. Compared with equal-leg angle steel, its two sides are of different lengths.
The side lengths of unequal angle steels range widely, from 25mm x 16mm to 200mm x 125mm. These steels are rolled through hot rolling mills and have excellent mechanical properties and weldability. In steel structure construction, unequal angle steels are often used as structural components for support, connection, and reinforcement to ensure the stability and safety of the building.
The characteristic of unequal-leg angle steel is that the lengths of the two sides are unequal, which makes it more suitable for certain structures.