1. Under normal circumstances, the dimensions of the straight seam steel pipes we come into contact with are all fixed. The more common ones are six meters, nine meters and twelve meters. Basically, the size of the steel pipe is made according to the needs of customers. However, seamless steel pipes rarely have a fixed size. Why? Because if the seamless steel pipe is made into a fixed size, it will increase the cost, and the price will naturally be high. Basically, many customers can't accept it under normal circumstances.
2. We can also see from the cross section at both ends of the pipe. If there is rust on the upper side, wipe it clean and look again. If you look closely, you will find traces of welding on the upper side.
①The quality inspection and acceptance of straight seam steel pipes are all checked and accepted by the supplier's quality supervision department.
②The supplier needs to ensure that the delivered straight seam steel pipe meets the requirements of the corresponding product standard. The purchaser has the right to inspect and accept according to the corresponding product standards. If it is unqualified, it will not be passed.
③The inspection items, sampling quantity and inspection methods of straight seam steel pipes need to meet the requirements of the corresponding product standards. After the purchaser's consent, hot-rolled seamless straight seam steel pipes can be sampled in batches based on the rolled root array.
④In the test results of straight seam steel pipes, when one of them does not meet the requirements of the product standard, it is necessary to immediately pick out those that do not meet the requirements, and immediately take the same batch of samples of the same batch of straight seam steel pipes to double the unqualified items for inspection. If the re-inspection result is unqualified, this batch of straight seam steel pipes cannot be delivered.
⑤If there are no special regulations in the product standard, acceptance should be carried out according to the chemical composition of the straight seam steel pipe according to the melting composition. This is also one of the methods that can be distinguished.
3. A straight seam steel pipe is a steel pipe with only one longitudinal weld. According to the process, it can be divided into LSAW steel pipes and LSAW steel pipes. Straight seam steel pipes are steel pipes whose welds are parallel to the longitudinal direction of the steel pipe.
The seamless steel pipe has a hollow cross-section, and its function is mainly used for pipelines that transport fluids, such as pipelines that transport oil, natural gas, gas and certain solid materials.
From a structural point of view, the difference is not very large. Straight seam steel pipes are not seamless. The centroid of the welded pipe may not be in the middle. Therefore, when we use it as a compression member during construction, we should pay more attention to the welded pipe welds.
The seamless steel pipe (A53 steel pipe) is limited by processing technology, and the wall thickness of the steel pipe will not be very thin. The big difference between seamless pipes and welded pipes is that they are used for the transmission of pressurized gas or liquid.