Structural steel pipe should theoretically be the same, the difference is not very big, LSAW pipe is not as regular as seamless pipe, welded pipe may not be in the centre of the form of the centre, so used as a compression member, especially pay attention to the welded pipe weld defects in the relatively high probability of important parts of the important parts of the pipe can not be replaced by a seamless pipe, seamless pipe by the limitations of the processing process can not be done to make a very thin tube wall thickness (the same diameter of the seamless pipe wall thickness on average to be thicker than welded pipe).In many cases, seamless pipe material use efficiency is not as good as welded pipe, especially large diameter pipe.The biggest difference between seamless pipes and welded pipes is that they are used for the transmission of pressurised gases or liquids (DN).