Differences between API 5L PSL1 and PSL2

Key Differences Between API 5L PSL1 and PSL2 Pipes

API 5L pipes, whether seamless or welded, are available in two product specification levels: PSL1 and PSL2. These two grades differ significantly in terms of chemical composition, manufacturing process, mechanical properties, heat treatment, documentation, and traceability.

PSL2 Offers Higher Quality Than PSL1

PSL stands for "Product Specification Level." The API 5L standard defines two main quality levels: PSL1 and PSL2. PSL2 is considered a higher-grade specification than PSL1. It not only includes more rigorous inspection requirements but also imposes stricter standards on chemical properties and mechanical strength. Therefore, when ordering API 5L pipes, it's essential to clearly specify the pipe grade, size, and most importantly, whether the product should meet PSL1 or PSL2 standards.

PSL2 is more stringent in several aspects, including chemical composition, tensile strength, non-destructive testing (NDT), and impact testing.

Different Impact Test Requirements for PSL1 and PSL2

For API 5L PSL1 pipes, impact testing is not required. However, PSL2 pipes have specific impact test requirements. For example:

  • Except for grade X80, all other API 5L PSL2 pipes must undergo an impact test at 0°C. The average Akv values should be: longitudinal ≥ 41 J, transverse ≥ 27 J.
  • All dimensions of API 5L X80 PSL2 pipes must also be tested at 0°C, with average Akv values of: longitudinal ≥ 101 J, transverse ≥ 68 J.

Different Hydrostatic Testing Requirements

In API 5L PSL2, every individual pipe must undergo a hydrostatic test. Unlike some other standards, the API specification does not allow NDT to replace hydrostatic testing. This is one of the key differences between the Chinese standard and the API 5L standard. While PSL1 may not require NDT, PSL2 requires NDT for each single pipe, ensuring greater quality control.

Variations in Chemical Composition and Mechanical Properties

The chemical composition and mechanical properties of PSL1 and PSL2 pipes are also distinct. For instance, API 5L PSL2 places stricter limits on carbon equivalent (CEQ). If the carbon content is above 0.12%, a different CEQ calculation is applied. Additionally, PSL2 line pipes have maximum tensile strength limits. For detailed specifications, refer to sections 9.2 and 9.3 of the API 5L standard.

Understanding these differences is crucial for selecting the right pipe grade based on project requirements, environmental conditions, and performance expectations. Always consult the official API 5L documentation for the most accurate and up-to-date information.

CNC Horizontal Lathe

Cnc Horizontal Lathe,Cnc Horizontal Lathe Machine,Cnc Lathe Machine,Industrial Lathe Machine

Suzhou Loong Won Machinery Technology Co., Ltd. , https://www.loongwon.com