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.). It can be divided into two product specification grades: PSL1 and PSL2.

PSL1: Standard quality control.
PSL2: More stringent chemical composition, mechanical property and inspection requirements, often used in harsh or acidic environments; Suffixes with N/Q/M/S indicate delivery status or applicable conditions.

API 5L ERW carbon steel pipe is made by resistance welding technology. After rolling the steel coil into a tubular shape, it is welded along the longitudinal direction of the tube wall and pressure is applied to completely fuse the two ends of the tube blank. Steel pipes produced by resistance welding have uniform weld seams, high dimensional accuracy, and can be mass-produced. They are particularly suitable for API 5L pipes of medium and small diameters. High-frequency ERW process can enhance the quality, strength and density of weld seams.

Common material grades and size ranges

Common material grades of API 5L tubes include gr.  B, X42, X46, X52, X56, X60, X65, X70. API 5L X60 ERW pipe, yield strength 415MPa, suitable for high-pressure conveyance.
The specifications of ERW pipes are usually: outer diameter 2 "- 24", and their wall thickness can meet various requirements such as Schedule 40 to Schedule 160, adapting to various working pressures and temperature conditions.

Chemical composition and mechanical properties

Take the typical Grade  birw tube as an example:
The carbon content is usually 0.26-0.28%, manganese - 1.2-1.4%, P/S ≤0.03%, and it may contain Cr, Ni, Mo, Cu and V.
Mechanical properties: Taking X60 as an example, the minimum yield strength of API 5L X60 ERW pipe is 360MPa, the minimum tensile strength is 460MPa, and the mechanical properties of different grades are also different.

Common testing methods

Chemical analysis, mechanical property testing and other methods are carried out on the pipes to test the yield strength, tensile strength, elongation and other properties of the steel pipes.
Technical performance testing: such as flattening test, bending test, hardness impact test, etc.
Non-destructive testing (NDT) : Common methods include ET (eddy current), RT (radiographic), and UT (ultrasonic) testing.
Hydrotest: It can effectively ensure the sealing performance and pressure-bearing capacity of the pipeline.

Typical application scenarios

Petroleum and natural gas pipelines: Widely used in the oil and gas industry, they feature pressure resistance, corrosion resistance, and reliable welds.
Engineering structure support, mechanical manufacturing: It can be used as storage racks, platform pillars, brackets, ladder beams, etc., and also as equipment structural components, rollers, hydraulic cylinder bodies, bearing sleeves, etc.
For drinking water or industrial water supply systems: PSL1 grade pipes are often used in medium and low pressure water supply projects, which are both economical and safe.

API 5L ERW carbon steel pipes are widely used in oil and gas transportation pipelines, water treatment projects, gas pipelines and industrial structures. Especially in high-pressure transportation and corrosive environments, when combined with anti-corrosion coatings (such as 3PE, FBE), it can effectively extend the service life of pipelines and reduce maintenance costs.

Why choose API 5L ERW Carbon Steel Pipe?

High cost performance: Compared with seamless pipes, ERW pipes have lower production costs and are suitable for large-scale purchases.
The manufacturing process is mature: Resistance welding technology ensures the stability of the weld seam and reduces safety hazards.
Diverse specifications: Meeting the requirements of various diameters and wall thicknesses, suitable for different engineering scenarios.
Widely applied: It performs exceptionally well in the petroleum, natural gas and water conservancy industries.