API is a standard formulated by the American Petroleum Institute for pipeline systems transporting fluids such as oil, natural gas, and water, covering seamless pipes and welded pipes (including ERW, LSAW, SSAW, etc.).

ERW carbon steel pipe is the abbreviation of resistance welded carbon steel pipe. It features efficient welding, uniform wall thickness and excellent mechanical properties.

A53 ERW carbon steel pipe (ASTM A53 resistance welded carbon Steel Pipe) is a kind of welded pipe produced in accordance with the American Society for Testing and Materials (ASTM A53/A53M) standard.

ERW (Electric Resistance Welded) carbon steel pipe is a kind of steel pipe formed by rolling steel plates or steel strips and then welded by resistance high-frequency welding.

Schedule 40 ERW carbon steel pipe is a medium wall thickness carbon steel pipe produced based on ERW (Electric Resistance Welded) in accordance with ANSI/ASME B36.10M "Schedule 40" standard.

ERW Carbon Steel Pipe, also known as Electric Resistance Welded Carbon Steel Pipe, is a kind of highly efficient welded steel pipe. It is formed by rolling steel coils or steel strips into pipe blanks through a forming machine, heating both ends of the pipe blanks with high-frequency current and welding the edges under pressure.

Steel pipe piles are a type of cylindrical steel structure and a common deep foundation structure. They can transfer the load of the superstructure to the deep hard soil or rock layer by directly driving or drilling into the foundation through frictional resistance and end bearing force.

Steel sheet piles are a commonly used structural component for support and retaining in civil engineering, usually composed of longitudinally interlocked thin-walled steel plates. They can interlock with each other through the interlocking at the edges to form continuous retaining walls or enclosure structures.

Large-diameter seamless steel pipes generally refer to large-sized steel pipes with an outer diameter of 300 millimeters or more, which are formed in one piece through processes such as hot rolling or hot expansion, and have no welds in the pipe body.

Seamless steel pipes are widely used in industries such as structures, fluid transportation, boilers, and oil and gas due to their excellent strength, pressure resistance, and extensive application fields.

LSAW (Longitudinal Submerged Arc Welded) steel pipes are manufactured by longitudinal Submerged arc welding. First, steel plates are rolled into tube blanks, and then longitudinal welds are formed through inner and outer submerged arc welding.

Ceramic linings and cement mortar linings are two relatively common types of linings in pipeline transportation. They differ in structure, performance, applicable scenarios, advantages and disadvantages, etc.

Concrete lined steel pipe and Cement lined steel pipe, as two common choices of steel pipes, each have their unique advantages and applicable scenarios.

Square tubes are steel pipes with typical hollow square cross-sections made from steel billets or steel strips through rolling or welding. They are also known as hollow profiles or structural square tubes.

In the standard system of the American Petroleum Institute (API), API 5L usually refers to the pipeline steel standard, which mainly includes two specifications: PSL1 and PSL2.