What are the commonly used straight seam steel pipes in industrial projects

First, the acceptance steps for straight seam steel pipes:

1. The approval procedure for batch acceptance of straight seam steel pipes should comply with the corresponding product standards.

2. Straight seam steel pipes should comply with the corresponding product standards, including inspection items, sampling quantity, sampling location, and test methods. With the buyer's consent, hot-rolled seamless steel pipes can be sampled in batches according to the number of rolled pieces.

3. If any items do not meet the product standard requirements, the non-conforming items should be selected, and two samples should be drawn from the same batch of straight seam steel pipes for re-inspection. If the re-inspection results do not meet the standards, the batch of straight seam steel pipes shall not be released from the factory.

4. Straight seam steel pipes that do not meet the standards (including items that do not meet the standards and are not allowed to be re-inspected) should be submitted to the supplier for acceptance at once, or a new batch should be subjected to reheat treatment (reheat treatment should not exceed two times).

5. If there are no special provisions in the product standard, the chemical composition of the straight seam steel pipe will be accepted based on the melt composition.

Second, what is the difference between straight seam steel pipes and high-frequency straight seam steel pipes?

Welded steel pipes with only one longitudinal weld seam are called straight welded steel pipes. According to GB/T 9711.1, straight welded steel pipes have a diameter greater than 914.4 mm, a welding angle of 180°, and can have two identical straight seam welds. Straight seam steel pipes can be divided into JCOE straight seam steel pipes and rolled straight seam steel pipes based on their production process. High-frequency straight seam, submerged arc straight seam, electric welded straight seam, and pipe straight seam are collectively referred to as straight seam steel pipes. High-frequency straight seam steel pipes utilize the high-frequency current skinning effect, causing high-temperature, short-time external force extrusion at both ends of the steel plate. This is a true electrodeless metal butt joint, using hot-rolled coils as raw material. The wall thickness of ERW high-frequency straight seam steel pipes can be controlled to approximately ±0 mm. The 2mm steel pipe ends conform to the American APL standard or GB/T 9711.1 standard. Pipe ends are cut, and the transport length is fixed. In recent years, ERW steel pipes have been widely used as the main steel pipes for natural gas pipeline projects and urban pipeline networks of gas companies. Currently, high-frequency straight seam steel pipes account for 60% of the world's steel pipes, a significant portion of the explosives left over from wars. Double-sided submerged arc welded straight seam steel pipe is also a type of straight seam steel pipe. Submerged arc welded straight seam steel pipe adopts the JCOE cold forming process, using welding wire and granular flux for submerged arc welding. The main production process of submerged arc welded straight seam steel pipe is flexible, capable of producing any specification with a wall thickness of 325~1420 mm. It largely meets international requirements for steel pipe dimensions. High-frequency straight seam steel pipe is typically used in domestic standard production. High-frequency straight seam steel pipe is often referred to as "original steel pipe," and the industry name differs from submerged arc welded straight seam steel pipe or thermal expansion high-frequency straight seam steel pipe; their names are often confused.