The quality inspection requirements for API 5L line pipe involve multiple aspects, including chemical composition of materials, tensile testing, and non-destructive testing. The following are specific quality inspection requirements:
api 5l steel Pipe Chemical composition:
- PSL-1 grade: For line pipe X52/L360 steel grade, the carbon content shall not exceed 0.28%, the manganese content shall not exceed 1.40%, the phosphorus content shall not exceed 0.030%, the sulfur content shall not exceed 0.030%, and there are other restrictions on alloying elements.
- PSL-2 grade: For line pipe L360N/X52N steel grade, the carbon content shall not exceed 0.24%, the silicon content shall not exceed 0.45%, the manganese content remains unchanged, the phosphorus content shall not exceed 0.025%, the sulfur content shall not exceed 0.015%, and there are other restrictions on alloying elements.
API 5L PSL1 PSL2 Pipe Tensile test:
- PSL-1 grade: The yield strength requirement is not less than 360MPa, and the tensile strength requirement is not less than 460MPa.
- PSL-2 grade: Yield strength ranges from 360MPa to 530MPa, tensile strength ranges from 460MPa to 760MPa, and yield strength ratio must be less than 0.93.
API 5L Seamless Line Pipe Nondestructive testing:
API 5L standard includes a variety of nondestructive testing methods, such as ultrasonic testing, liquid penetrant testing, magnetic saturation eddy current testing, magnetic flux leakage testing, etc., which are used to check the internal and surface defects of steel pipes.
