In terms of manufacturing methods, galvanized steel pipes are divided into welded steel pipes for low-pressure fluid transportation, electric welded pipes, spiral seam electric welded steel pipes, etc. Seamless steel pipes can be used in various liquid and gas pipelines, etc. Welded pipes can be used for water pipes, gas pipes, heating pipes, etc.
Steel pipes can be divided into two categories according to the production method: seamless steel pipes and welded steel pipes.
1. According to the production method, seamless steel pipes can be divided into: hot-rolled seamless pipes, cold-drawn pipes, precision steel pipes, thermal expansion pipes, cold spinning pipes and extruded pipes. Seamless steel pipes are made of high-quality carbon steel or alloy steel, and can be divided into hot-rolled and cold-rolled (drawn).
2. Welded steel pipes are divided into furnace welded pipes, electric resistance welding (resistance welding) pipes and active arc welded pipes due to their different welding processes. It is round welded pipe and special-shaped (square, flat, etc.) welded pipe. Welded steel pipes are welded by steel plates rolled into a tubular shape with opposite seams or spiral seams.
Classification by raw materials Steel pipes can be divided into carbon pipes, alloy pipes, stainless steel pipes, etc. according to the pipe-making raw materials (ie steel types). Carbon tubes can be divided into general carbon steel tubes and high-quality carbon structural tubes. Alloy pipes can be divided into: low alloy pipes, alloy structural pipes, high alloy pipes, and high strength pipes. Bearing tubes, heat-resistant and acid-resistant stainless tubes, fine alloy (such as Kovar alloy) tubes and high-temperature alloy tubes, etc.
According to the connection method, the steel pipe can be divided into: threaded pipe and bare pipe according to the pipe end connection method. The threaded tube is divided into: general threaded tube and pipe end thickened threaded tube. Thickened threaded tubes can also be divided into: externally thickened (with external threads), internally thickened (with internal threads) and surface-intensified (with internal and external threads) and other surface-threaded tubes. Threaded pipes can also be divided into threaded pipes according to thread type: general cylindrical or conical threads and special threaded pipes.
