API 5L Pipe general:

API 5L pipes is used for conveying gas, water and oil either in the oil or natural gas industries. Line pipe can meet all requirement of high-pressure transmission pipeline for natural gas & petroleum, can be used in on-shore, off-shore oil & gas transmission.

API 5L ~ American Petroleum Institute specification API 5L cover seamless or welded steel line pipe. The purpose of this specification is to provide standards for pipe suitable for use in conveying gas, water, and oil in both the oil and natural gas industries.


Grades covered by this specification are A25, A, B and the followed by “X” Grades (X42, X46, X52, X56, X60, X65, X70, X80). The two digit number following the “X” indicates the Minimum Yield Strength (in 000’s psi) of pipe produced to this grade.


Pls refer to other topic for more information – Pipe & piping

api 4

Chemical & Mechenical properties:

The API committee issues standards in regards to these pipes, that most Energy companies require adherence to. PSL-1 and PSL-2 are standards that have been put in place to help with the more strict requirements for each grade. These two basic specifications are in part recognized as different levels of physical and technical requirements.

api 5
api 6

PSL-1 is a loose standard quality for API 5L pipe, whereas PSL-2 contains additional testing requirement, stricter chemical physicals, along with different ceiling limits of mechanical properties, and require Charpy impact testing conditions.

api 9

Furthermore, additional testing requirements under PSL-2 include CVN testing, non-destructive inspection of seamless products, certification to SR15, and mandatory trace-ability throughout the entire production process. Most FERC, DOT, or FEMSA lines require PSL-2, meaning these types of requirements are a must when supplying pipe for pipelines that are regulated by any of these governing bodies ( pls find define in specification for more understand: SR15, FERC, DOT, FEMSA… )

API 5L: PSL 1& PSL 2 comparison information / difference: 



+ PSL is short for the product specification levels. Product specification level pipeline is divided into PSL1 and PSL2, it can be said the quality level is divided into PSL1 and PSL2. PSL2 is higher than PSL1, these two specification level not only have difference testing requirements, and the chemical composition, mechanical properties requirement are different, so, when ordering according to API 5L, terms of the contract in addition to the indicators of the size & grade, must also indicate the product specification level, ex PSL 1 or PSL 2. PSL2 in chemical composition, tensile properties, the impact energy, non-destructive testing and other indicators are more stringent than PSL 1.

PSL2 do require Impact test.

+ PSL2 prohibited to repair on Damaged surface by Welding

4 thoughts on “PIPE API 5L: PSL1 vs PSL2

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s