Comparison of quality standards between PSL1 and PSL2

In the API 5L steel pipe standard, the quality standards (or requirements) of steel pipes are divided into PSL1 and PSL2. PSL is an abbreviation for product specification level. PSL1 provides general pipeline quality level requirements; PSL2 adds mandatory requirements for chemical composition, notch toughness, strength properties and supplementary NDE. The following is a comparison of PSL1 and PSL2 in terms of quality standards:

1.The quality standard of PSL2 is higher than that of PSL1. These two specification levels are not only different in inspection requirements, but also in chemical composition and mechanical performance requirements. Therefore, when ordering according to API 5L, in addition to the usual indicators such as specifications and steel grades, the terms in the contract must also indicate the product specification level, that is, PSL1 or PSL2. PSL2 is stricter than PSL1 in terms of chemical composition, tensile properties, impact energy, non-destructive testing and other indicators.

2.PSL1 does not require impact performance. For all steel grades except X80 of PSL2, the average value of Akv (impact energy) at 0°C in the full size: longitudinal ≥ 41J, transverse ≥ 27J. Full-scale 0℃ Akv average of X80 steel grade: longitudinal ≥ 101J, transverse ≥ 68J.

3. The line pipe should be subjected to hydraulic test one by one, and the standard does not stipulate that non-destructive substitution of water pressure is allowed. This is also a big difference between the API standard and the Chinese standard. PSL1 does not require non-destructive testing, and PSL2 should be non-destructive testing one by one.