Steel pipes can be divided into two categories according to consumption methods: seamless steel pipes and seam steel pipes. Seam steel pipes are referred to as straight seam steel pipes for short. Seamless steel pipes can be divided into hot-rolled seamless pipes, cold-drawn pipes, fine steel pipes, hot-expanded pipes, cold-spinned pipes, and extruded pipes according to consumption methods. Seamless steel pipes are made of high-quality carbon steel or alloy steel, and are divided into hot-rolled and cold-rolled (drawn). The main feature of seamless steel pipe is that it has no welded seam and can accept greater pressure.
The product can be a rough cast or cold drawn part. Welded steel pipes are divided into furnace welded pipes, electric resistance welded (resistance welded) pipes and automatic arc welded pipes due to their different welding processes. Due to their different welding methods, they are divided into two types: straight seam welded pipes and spiral welded pipes. Because of their end shapes, they are divided into round Shaped welded pipe and special-shaped (square, flat, etc.) welded pipe.
Welded steel pipes are formed by welding steel plates rolled into a tube shape with butt seams or spiral seams. In terms of manufacturing methods, they are divided into welded steel pipes for low-pressure fluid transportation, spiral seam electric welded steel pipes, direct coil welded steel pipes, and electric welded pipes. Seamless steel pipes can be used for liquid pressure pipes and gas pipes in various industries. The welding channel can be used for water pipelines, gas pipelines, heating pipelines, electrical pipelines, etc.
Fine steel pipe is a product that has appeared in recent years, mainly because the inner hole and outer wall dimensions have strict tolerances and roughness. Fine steel pipe is a kind of high-precision steel pipe material after cold drawing or hot rolling treatment. Since the inner and outer walls of fine steel pipes have no oxide layer, no leakage under high pressure, high precision, high brightness, cold bending, no deformation, flaring, flattening and no cracks, etc., they are mainly used to produce pneumatic or hydraulic components, such as cylinders or Cylinder.