Steel pipes are essential materials in modern industry, construction, and infrastructure. Due to differences in materials, manufacturing processes, performance characteristics, and application fields, beginners often find it confusing to select the right type of steel pipe. This article provides a comprehensive explanation of the main types of steel pipes, their features, advantages, and typical applications, helping you quickly build a complete knowledge framework and make informed decisions.
1. Seamless Steel Pipe
Features:
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Made by perforating solid steel billets and forming them through hot rolling or cold drawing without welding, resulting in excellent integrity.
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Smooth internal and external surfaces, high dimensional accuracy, and uniform mechanical properties.
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Resistant to high temperatures and pressures, suitable for harsh and demanding environments.
Typical Applications:
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High-pressure boiler pipes and steam transmission.
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Oil drilling pipes and natural gas pipelines.
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Mechanical parts like drive shafts and load-bearing structures.
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Nuclear power, aerospace, and military industries.
2. Welded Steel Pipe
Features:
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Produced by rolling and welding steel plates or coils, featuring mature manufacturing technology and lower costs.
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Suitable for mass production with customizable outer diameter and wall thickness.
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The welded seam has slightly lower strength than seamless pipes but performs well under normal pressure conditions.
Typical Applications:
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Residential water pipes and gas lines.
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Structural supports in buildings, bridges, and greenhouses.
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Low-pressure oil and gas transportation.
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Exhaust and ventilation systems.
3. Spiral Welded Pipe
Features:
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Formed by spirally rolling steel strips and continuously welding them, with evenly distributed weld seams and stable strength.
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Capable of producing large-diameter pipes in long lengths, ideal for long-distance pipelines.
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Highly automated welding process, suitable for mass production.
Typical Applications:
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Oil and gas transmission pipelines.
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Large municipal water supply and drainage networks.
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Foundation piles for bridges, docks, and groundworks.
4. Straight Seam Welded Pipe (ERW/LSAW)
Features:
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The welding seam runs parallel to the pipe's axis, offering precise welding and uniform strength.
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High production efficiency, suitable for small to medium diameters.
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Common manufacturing processes include Electric Resistance Welding (ERW) and Longitudinal Submerged Arc Welding (LSAW).
Typical Applications:
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Urban oil and gas networks.
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Square and rectangular tubes for structural supports.
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Highway guardrails and posts.
5. Galvanized Steel Pipe
Features:
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Coated with a layer of zinc to prevent oxidation and corrosion, greatly improving service life.
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Available in hot-dip galvanizing (thicker zinc coating, stronger corrosion resistance) and electro-galvanizing (smoother, more uniform coating).
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Silver-white appearance, ideal for outdoor and humid environments.
Typical Applications:
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Water supply and heating pipelines.
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Outdoor protection structures like balconies and fences.
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Agricultural greenhouse frames and protective sheds.
6. Alloy Steel Pipe
Features:
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Alloyed with elements like chromium, molybdenum, vanadium, and nickel to improve heat resistance, corrosion resistance, and strength.
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Higher cost than ordinary carbon steel pipes, but superior performance.
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Can withstand long-term high-temperature and high-pressure environments with excellent wear and impact resistance.
Typical Applications:
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Boiler pipes and heat exchangers in thermal power plants.
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Corrosion-resistant equipment in the chemical industry.
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Nuclear power stations and military applications.
7. Stainless Steel Pipe
Features:
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Contains high levels of chromium (Cr) and nickel (Ni), providing excellent corrosion and oxidation resistance.
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Attractive appearance, easy to clean, combining functionality and aesthetics.
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Excellent mechanical properties, suitable for repeated welding and forming.
Typical Applications:
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Sanitary fluid pipelines in the food and pharmaceutical industries.
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Marine engineering and highly corrosive chemical processing environments.
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Decorative railings and stair handrails in buildings.
8. Precision Steel Pipe
Features:
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Manufactured through cold drawing or cold rolling, achieving extremely small dimensional tolerances and smooth surfaces.
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Offers excellent dimensional consistency and concentricity, ideal for precision machining.
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Stable mechanical performance, balancing strength and toughness.
Typical Applications:
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Automotive hydraulic systems and fuel pipelines.
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Components in CNC machinery and industrial robotics.
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Precision bearings and mechanical transmission systems.
9. Casing and Tubing
Features:
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Specially designed for oil and gas drilling, suitable for extreme operating conditions.
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High strength, corrosion resistance, and pressure resistance to stabilize wellbores.
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Includes casing, tubing, and drill pipe categories.
Typical Applications:
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Onshore and offshore oil and gas wells.
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Shale gas fields, deep-sea oil fields, and arctic oil and gas extraction.
10. Plastic Coated Steel Pipe
Features:
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Internally and externally coated with polyethylene (PE), epoxy (EP), or other corrosion-resistant materials.
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Excellent corrosion resistance, wear resistance, and anti-scaling properties, extending service life.
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Smooth inner walls reduce fluid resistance and improve conveying efficiency.
Typical Applications:
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Municipal water supply and drinking water systems.
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Chemical liquid transportation and wastewater discharge systems.
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Fire sprinkler pipe networks.
11. Square & Rectangular Steel Pipe
Features:
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Square or rectangular cross-section, evenly distributed stress, and stable structures.
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Easy to weld, drill, and cut, suitable for secondary processing.
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Practical and attractive, widely used in structural and decorative fields.
Typical Applications:
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Building frameworks and curtain wall supports.
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Furniture frames and sports equipment.
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Billboards and signage structures.
12. Hydraulic Steel Pipe
Features:
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Manufactured using cold-drawn seamless steel pipe technology for excellent pressure resistance.
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Clean inner and outer surfaces to prevent hydraulic oil contamination.
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High dimensional accuracy, suitable for precision hydraulic systems.
Typical Applications:
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Hydraulic systems in construction machinery and industrial equipment.
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High-pressure gas and fluid transmission systems.
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Industrial automation equipment and cranes.
Summary: How to Choose the Right Steel Pipe?
Each type of steel pipe has its own advantages. You should select the right pipe according to your working environment, medium type, pressure requirements, and budget. For high-pressure and high-temperature applications, seamless and alloy steel pipes are recommended. For general purposes, welded and galvanized pipes offer a cost-effective choice. In highly corrosive or aesthetically demanding environments, stainless steel and plastic-coated pipes are ideal.
