Steel pipes can be divided into two categories according to production methods: seamless steel pipes and welded steel pipes. Welded steel pipes are referred to as welded pipes.
1. Seamless steel pipes can be divided into hot-rolled seamless pipes, cold-drawn pipes, precision steel pipes, thermal expanded pipes, cold spinning pipes and extruded pipes according to production methods.
Seamless steel pipes are made of high-quality carbon steel or alloy steel, and are divided into hot-rolled and cold-rolled (drawn).
2. Welded steel pipes are divided into furnace welded pipes, electric welded (resistance welded) pipes and automatic arc welded pipes due to their different welding processes. They are divided into straight seam welded pipes and spiral welded pipes due to their different welding forms. They are further divided into two types due to their end shapes. For round welded pipes and special-shaped (square, flat, etc.) welded pipes.
Welded steel pipes are made of steel plates rolled into tubular shapes and welded 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, electric welded pipes, etc. Seamless steel pipes can be used in liquid pneumatic pipelines and gas pipelines in various industries. Welded pipes can be used for water pipes, gas pipes, heating pipes, electrical pipes, etc.
Material classification
Steel pipes can be divided into carbon pipes, alloy pipes, stainless steel pipes, etc. according to the pipe material (i.e. steel type).
Carbon pipes can be divided into ordinary carbon steel pipes and high-quality carbon structural pipes.
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 steel tubes, precision alloy (such as Kovar alloy) tubes and high-temperature alloy tubes, etc.
Connection method classification
Steel pipes can be divided into plain pipes (pipe ends without threads) and threaded pipes (pipe ends with threads) according to the pipe end connection method.
Threading tubes are further divided into: ordinary threading tubes and threading tubes with thickened ends.
Thickened wire tubes can also be divided into: externally thickened wire tubes (with external threads), internally thickened wire tubes (with internal threads), and internally and externally thickened wire tubes (with internal and external threads).
Threaded pipes can also be divided into ordinary cylindrical or conical threaded threaded pipes and special threaded threaded pipes according to the thread type.
In addition, according to user needs, wire pipes are generally delivered with pipe joints.
Plating characteristic classification
Steel pipes can be divided into black pipes (uncoated) and coated pipes according to surface coating characteristics.
Coated pipes include galvanized pipes, aluminum-plated pipes, chrome-plated pipes, aluminized pipes and other alloy-layered steel pipes.
Coated pipes include outer coated pipes, inner coated pipes, and inner and outer coated pipes. Commonly used coatings include plastic, epoxy resin, coal tar epoxy resin and various glass-type anti-corrosion coating materials.
Galvanized pipes are divided into: KBG pipes, JDG pipes, threaded pipes, etc.
Classification Purpose Classification
1. Pipes for pipes. Such as: seamless pipes for water, gas pipes, steam pipes, oil transportation pipes, and pipes for oil and natural gas trunk lines. Agricultural irrigation faucet pipes and sprinkler irrigation pipes, etc.
2. Pipes for thermal equipment. Such as boiling water tubes, superheated steam tubes used in general boilers, superheated tubes, large smoke tubes, small smoke tubes, arch brick tubes and high temperature and high pressure boiler tubes used in locomotive boilers.
3. Pipes for mechanical industry. Such as aviation structural pipes (round pipes, elliptical pipes, flat elliptical pipes), automobile axle pipes, axle pipes, automobile tractor structural pipes, tractor oil cooler pipes, square pipes and rectangular pipes for agricultural machinery, transformer pipes and bearings Guan et al.
4. Pipes for petroleum geological drilling. Such as: oil drilling pipe, oil drill pipe (kelly and hexagonal drill pipe), drill jack, oil pipe, oil casing and various pipe joints, geological drilling pipe (core pipe, casing, active drill pipe, drill jack , press hoops and pin joints, etc.).
5. Pipes for chemical industry. Such as: petroleum cracking pipes, pipes for chemical equipment heat exchangers and pipelines, stainless acid-resistant pipes, high-pressure pipes for fertilizers, and pipes for transporting chemical media, etc.
6. Manage other departments. Such as: tubes for containers (tubes for high-pressure gas cylinders and general container tubes), tubes for instruments, tubes for watch cases, tubes for injection needles and medical equipment, etc.
