The biggest advantage of large diameter alloy steel pipe is that it can be recycled 100%.Seamless steel pipe is divided into hot-rolled (extruded) seamless steel pipe and cold-drawn (rolled) seamless steel pipe because of its different manufacturing technology. Cold-drawn (rolled) pipes are divided into circular pipes and special-shaped pipes. Sales of large-caliber alloy steel pipes are mainly used to transport high temperature and high pressure fluid pipelines on fertilizer equipment. The representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc. Large-diameter alloy steel pipe is defined according to the material used in production (i.e. material), as the name implies, it is made of alloy pipe; seamless pipe is defined according to the production process (seamless), which is different from seamless pipe is seamless pipe, including straight welded pipe and spiral pipe.