Classification by Production Method
1. Seamless Steel Pipe
Seamless steel pipe is made by perforating a solid round bar, with no weld seams on the surface. Types include hot-rolled steel pipe, cold-drawn steel pipe, precision steel pipe, heat-expanded pipe, cold-spun pipe, and extruded pipe.
2. Welded Steel Pipe
Welded steel pipe is made by welding rolled steel plates together with butt or spiral seams. It can be simply categorized as straight seam pipe and spiral pipe.
Classification by Steel Pipe Material
Steel pipe can be categorized by the material (i.e., steel grade) of the pipe: carbon steel pipe (also known as carbon steel pipe), alloy steel pipe, stainless steel pipe, etc. Carbon pipe can be further divided into ordinary carbon steel pipe and high-quality carbon structural pipe. Alloy pipe can be further categorized into low-alloy pipe, alloy structural pipe, high-alloy pipe, high-strength pipe, precision alloy (such as Kovar) pipe, and high-temperature alloy pipe.
Classification by Coating Characteristics
Steel pipes can be divided into two types based on surface coating characteristics: coated steel pipes and uncoated steel pipes (also known as black pipes). Coated steel pipes further include galvanized pipes, aluminum-coated pipes, chrome-coated pipes, and aluminized pipes.
Classification by Cross-sectional Shape
Steel pipes can be divided into two types based on cross-sectional shape: circular steel pipes and special-shaped steel pipes. Special-shaped steel pipes refer to steel pipes with non-circular cross-sections, such as square pipes, rectangular pipes, elliptical pipes, semicircular pipes, hexagonal pipes, and pentagonal plum blossom pipes.
Steel pipes can be categorized by application into pipelines (water pipes, gas pipes, oil pipelines, etc.), thermal equipment pipes (boiling water pipes, superheated steam pipes, etc.), machinery industry pipes (aerospace structural pipes, automotive axle pipes, transformer pipes, etc.), petroleum and geological drilling pipes (petroleum drilling pipes, oil pipes, core pipes, etc.), chemical industry pipes (petroleum cracking pipes, chemical equipment heat exchangers and pipelines, stainless and acid-resistant pipes, etc.), and pipes for other sectors (container pipes, instrumentation pipes, etc.).