API 5L X70 PSL2 is a specification that covers seamless and welded steel line pipes for the transportation of oil, gas, and water in pipeline systems. It is part of the API 5L specification and is categorized under the higher-performance PSL2 (Product Specification Level 2) standard, which requires stricter testing and material requirements than PSL1.

Key Specifications of API 5L X70 PSL2:

Material Grade: X70

X70 represents a minimum yield strength of 70,000 psi (about 485 MPa).

Chemical Composition (varies slightly based on the manufacturing process, but typically includes):

Carbon (C): Maximum 0.22%

Manganese (Mn): 1.10-1.65%

Phosphorus (P): Maximum 0.025%

Sulfur (S): Maximum 0.015%

Other elements: Trace amounts of Ni, Cu, Cr, and Mo may be present to enhance strength and resistance.

Mechanical Properties:

Yield Strength: Minimum 485 MPa (70,300 psi)

Tensile Strength: 570 - 760 MPa (82,665 - 110,200 psi)

Elongation: Varies with pipe dimensions, typically 21-23%

Toughness Requirements:

For PSL2, toughness testing (Charpy impact test) is required to ensure fracture toughness, especially in colder environments.

Pipe Manufacturing Process:

Pipes can be made using seamless, welded, or ERW (Electric Resistance Welded) methods.

Dimensions:

Available in various diameters and wall thicknesses according to customer specifications and industry standards.

Applications:

Mainly used in high-pressure oil and gas pipelines due to its strength and toughness.

Testing and Certification:

PSL2 requires more stringent testing than PSL1, including chemical analysis, mechanical tests, fracture toughness, and non-destructive testing (NDT) such as ultrasonic or radiographic tests.

API 5L X70 PSL2 is chosen for critical infrastructure projects where strength, toughness, and reliability are vital.