Before purchasing large-diameter straight seam steel pipes (LSAW), you should follow the pre-designed specifications, lengths, materials, wall thicknesses, welding standards and weld requirements, which must be communicated well before purchasing.
1. The first is the specification. For example, 800mm is also called DN800, including 820mm and 813mm of A and B series, or the outer diameter of 800mm must be clearly required to avoid unnecessary losses.
2. The wall thickness of large-diameter straight seam steel pipe is required to be 16mm. It is possible that the actual thickness of the raw materials will be 15.75mm and 16.2mm, and there will be upper or lower differences. These are normal deviations. Because straight seam steel pipes are all ton prices, it is necessary to communicate in advance to avoid differences in weight.
3. The normal length of the large-diameter straight seam steel pipe is 12m. When it needs to be fixed, it needs to be communicated in advance, because the price of the fixed length will be more expensive. If it is not communicated in advance, it will be 9.87m long, and the manufacturer generally gives 9.9m directly.
4. The materials for purchasing large-diameter straight seam steel pipes should also be communicated well, and the materials should not be OEM. In addition, the materials should be guaranteed, and the original material list of the steel mill should be provided. Any material problems will be returned and compensated.
5. The welding standard for production and processing must be in accordance with automatic submerged arc welding LSAW GB/T3091-2015, and a product quality certificate is required. If the standard does not meet the requirements, the product fails.
6. When purchasing large-diameter straight seam steel pipes, it is required to communicate in advance about the level of weld flaw detection, because weld flaw detection will cost extra money. trouble.
7. In addition, large-diameter straight seam steel pipes above 1020mm may produce two welds. Many projects will not accept two welds without prior communication, and will be called defective steel pipes.
Therefore, it is necessary to communicate well in advance before purchasing any steel pipe, causing unnecessary disputes and economic losses.