Before purchasing large -caliber steel pipes, you should communicate in accordance with the pre -designed specifications, length, material, wall thickness, welding standards and weld requirements. You must communicate before purchasing.
1. First of all, specifications. For example, 800mm is also called DN800, including 820mm and 813mm of the A and B series, or the outer diameter of 800mm must be clearly required to avoid unnecessary losses.
2. The wall thickness requirements of large -caliber straight steel pipes are 16mm. The actual thickness of the raw materials may be 15.75mm and 16.2mm, which will be different. These are normal deviations. Because the straight seam steel pipes are tons, they need to communicate in advance to avoid differences in weight.
3. The normal length of the large -caliber straight steel pipe is 12m. You need to communicate in advance when you need to fix it, because the price of the fixed length will be more expensive. If you do not communicate in advance, it is 9.87m long, and the manufacturer generally gives 9.9m directly.
4. The materials for the purchase of large -caliber straight steel pipes must be communicated well, and the materials cannot be well -behaved. In addition, the materials must be guaranteed and the original material list of the steel mill will be provided. Any material issues will be returned and compensated.
5. The welding standard for production and processing must comply with automatic buried arc welding LSAW GB/T3091-2015, and requires product quality certificates. If the standard does not meet the requirements, the product is not qualified.
6. When buying large -caliber straight steel pipes, you need to communicate the level of welded seams in advance, because the welding seam detection requires additional money. trouble.
7. In addition, large -caliber straight steel pipes above 1020mm may produce two welded seams. Many projects do not accept two welds without accepting pre -communication, and they will be called defective steel pipes.
Therefore, before buying any steel pipe, you need to communicate well in advance, causing unnecessary disputes and economic losses.
