Issues with domestic steel pipe procurement

Generally, it is expressed as diameter * wall thickness. I have seen tender documents with the following requirements: Specification, Unit, Quantity, Unit weight (Kg), Total weight (Kg). Remarks: 1. The technical standards to be applied for seamless steel pipes. 2. Minimum size of the steel pipe. 3. The delivery weight of the steel pipe must meet the requirements of the theoretical weight. 4. The delivered steel pipes shall be accompanied by a quality certificate, indicating the steel grade, batch number, specifications, factory inspection mark, and standard number.

As an additional note: In addition to the items mentioned by friend LS, we usually specify our requirements to suppliers using the outer diameter and wall thickness of seamless steel pipes as the parameters, with length measured in meters; we also indicate the specific material and the corresponding standard number. For reference!

Find a steel pipe standard, such as GB8163, which details the information that should be specified when purchasing steel pipes

First, determine whether to purchase large-diameter or small-diameter pipes, and then provide the material and pipe grade; for example, if purchasing ASME standards pipes: PIPE A106-B SMLS PE SCH80

Generally, we just need to specify the outer diameter, wall thickness, and the length of each piece, as well as how many pieces to order. We also need to indicate the material type, desired condition, and the national standards according to which they should be manufactured

Purchasing actual seamless steel pipes requires some knowledge. First of all, don’t assume that just because there is a material report available it means the pipe is indeed seamless; there are many fake seamless pipes in China, such as welded pipes that are presented as seamless, and judgment in such cases relies entirely on experience. There are generally two domestic standards for seamless pipes: one is GB8163, and the other is SH3405-96 (a petrochemical standard). The 8163 standard is also divided into A and B series; for example, for pipes with a diameter of 100, one may have an outer diameter of 108 while another has 114. In addition, seamless pipes are generally not supplied in fixed lengths – if no special requirements are specified, all pipes will be of the same length, and in such cases there is a high probability that there will be problems. There are also seamless pipes that are not sold at their theoretical weight; since there is a upper deviation for such pipes, they are sold after being weighed. If you bought the lower deviation version, there might also be a problem. Now many small factories can also produce seamless pipes, but the quality is not satisfactory. It’s better to buy from a major brand. Also, it’s very difficult to buy it directly from the steel mills; they ignore you, haha