GB/T 9711 PSL1 vs PSL2

In the oil and gas industry, the national standard GB/T 9711 sets a benchmark for the technical requirements of conveying steel pipes. Among them, PSL1 and PSL2, as key product specification levels, represent different levels of quality and performance requirements, respectively, and constitute the quality double peaks of the steel pipe market.

1. Chemical composition and mechanical properties: the boundary between strict and loose
PSL2 stands out for its strict chemical composition and mechanical properties. In terms of key indicators such as tensile strength, yield strength and elongation, PSL2 sets higher standards than PSL1 to ensure the stable performance of steel pipes under extreme working conditions. In contrast, although PSL1 also has corresponding requirements, it is relatively loose and suitable for general working conditions.

2. Impact performance: the watershed of toughness
In terms of impact performance, the difference between PSL2 and PSL1 is particularly significant. PSL2 requires that all steel grades except X80 steel grade must pass strict impact toughness tests to ensure the crack resistance of steel pipes in low temperature environments. PSL1 exempts this requirement, reflecting the different pursuits of the two in material toughness.

3. Nondestructive testing: a sharp tool for quality control
Nondestructive testing is an important means to ensure the quality of steel pipes. PSL2 clearly stipulates that nondestructive testing must be carried out on each pipe to eliminate potential defects and ensure that each steel pipe is flawless. However, PSL1 does not list nondestructive testing as a mandatory inspection item, reflecting the difference in the strictness of quality control between the two.

4. Other details: the attitude of striving for excellence
In addition to the above core differences, PSL2 also shows higher standards in pipe end treatment, special material setting and testing requirements. For example, the pipe ends of PSL2 steel pipes need to be sandblasted to improve the reliability of subsequent connections; at the same time, special tests such as NACE hardness and acid resistance tests may also be carried out according to customer needs. These details all demonstrate PSL2's unremitting pursuit of quality.