1. Classification of Steel Pipes
By Production Process
Seamless Steel Pipe: No welded seam, made by hot rolling, cold rolling or cold drawing. High strength and pressure resistance, suitable for high-pressure and high-temperature conditions.
Welded Steel Pipe: Made by rolling steel strips and welding. Low cost, complete specifications, widely used in civil and general engineering.
By Surface Anti-corrosion Treatment
Black Pipe: Without anti-corrosion treatment, easy to rust.
Hot-dip Galvanized Steel Pipe: With zinc coating, strong rust resistance, long service life.
Epoxy Coated Steel Pipe: Resistant to acid, alkali and corrosion, ideal for buried and sewage projects.
Plastic Coated Lined Steel Pipe: Good for drinking water and chemical fluid transportation.
2. Main Production Processes
Seamless Process: Heating → piercing → rolling → sizing → straightening → inspection.
Welding Process: Rolling → high-frequency welding → straightening → cutting.
Anti-corrosion Process: Surface treatment → galvanizing or coating → curing → inspection.
3. Typical Applications
Construction: Scaffolds, structural supports, fire pipelines, water supply systems.
Municipal Engineering: Urban water supply, drainage, gas pipelines.
Fire Protection Systems: Mainly use galvanized steel pipes.
Petrochemical Industry: Seamless pipes and epoxy coated pipes.
Agriculture & Industry: Irrigation, compressed air pipelines, mechanical structures.
4. Key Selection Tips
Select by environment: Galvanized pipes for general use; epoxy coated pipes for corrosive environments; seamless pipes for high pressure.
Select by pressure: High-pressure projects prefer thick-walled or seamless pipes.
Select by installation: Galvanized pipes for threading and grooving; black pipes and seamless pipes for welding.
Select by cost: Short-term projects use ordinary pipes; long-term projects use high anti-corrosion pipes.
Summary
Steel pipes are fundamental materials for both civil and industrial fields. Seamless pipes focus on strength, welded pipes on cost, and anti-corrosion pipes on service life. Reasonable selection based on environment, pressure and budget ensures safety, durability and economy.