A Brief Introduction of API 5L-Part 1

API 5L is the Specification for Line Pipe, it is used widely on petroleum. This Standard has high reputation and accepted by most petroleum in the world. We will make a brief introduce of API 5L standard:

On API 5L Specification, there have two basic levels of standard technical requirements for line pipe expressed as two product specification levels (PSL1 and PSL2).

The scope: This Standard specifies requirements for the manufacture of two product specification levels (PSL1 and PSL2) of seamless and welded steel pipes for use in pipeline transportation systems in the petroleum and natural industries.

The Standard stipulate almost all sides of the pipe: the materials chemical component, mechanical property, outside diameter tolerance, wall thickness tolerance, length tolerance, roundness, straightness, surface treatment, ends treatment, tolerance of welding seam, Inspection frequency, inspection documents, markings, etc.

It also requires a series test for the pipe: Hydrostatics test, flatting test, bending test, guided-bend test, CVN impact test. The exact requirements need to supplier and client both parties’ confirmation.

The following we will introduce the key parts of the above information.

  1. Pipe grade and delivery condition.

The pipe grades is consist of an alpha or alphanumeric designation that identifies the strength level of the pipe and is linked to the chemical composition of the steel, and for PSL 2 there includes a suffix that consists of a single letter (R, N, Q or M) that identifies the delivery condition.

R means as rolled.

N means normalizing rolled, normalizing formed, normalized or normalized and tempered.

Q means Quenched and tempered.

M Means Thermomechanical rolled or thermomechanical formed.

  • Chemical composition and mechanical property

The chemical composition of the PSL1 and PSL2 pipe are different, the requirements should mark on purchase order, both parties should compliance the agreed requirements

The tensile strength usually can show on the steel grade, like L245 means the min tensile strength is 245MPa.

The next part will introduce the pipe tolerance and inspection requirements.

 More information or request, please contact steel@tuspipe.com

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