Before purchasing large-diameter spiral steel pipe, purchase according to pre-designed specifications, length, material, wall thickness, welding standards, and weld requirements, ensuring thorough pre-purchase communication.

First, consider the standard. For example, 800mm is also known as DN800, and also includes 820mm and 813mm in the A and B series. Alternatively, the outer diameter of 800mm should be clearly indicated to avoid unnecessary losses.

The wall thickness requirement for large-diameter straight seam steel pipe is 16mm. The actual thickness of the raw material may vary between 15.75mm and 16.2mm, with some fluctuation. These fluctuations are normal. Since straight seam steel pipe is priced by tonnage, prior communication is necessary to avoid weight discrepancies.

The standard length of large-diameter straight seam steel pipe is 12 meters. If a custom length is required, it is recommended to communicate in advance, as the price of custom lengths will be relatively higher. If no prior communication is made, the typical length is 9.87 meters, and the manufacturer will generally provide 9.9 meters directly. 

 When purchasing large-diameter straight seam steel pipe, ensure thorough communication with the supplier to ensure that the materials used are not OEM products. A raw material list from the steel mill must be provided to verify the authenticity of the materials. Any material issues will result in a return and compensation.

Welding standards during production and processing must comply with the requirements of Automatic Submerged Arc Welding (LSAW) GB/T3091-2015, and a product quality certificate must be provided. If these standards are not met, the product will be deemed unqualified.

When purchasing large-diameter straight seam steel pipe, be sure to confirm weld inspection requirements in advance, as this testing incurs additional costs.

In addition, large-diameter straight seam steel pipe over 1020 mm may have two welds. Many projects do not allow the use of two welds without prior consultation, and this will be considered a defective pipe.

Thus, prior consultation is crucial before purchasing any steel pipe to avoid unnecessary disputes and financial losses.

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