API 5L X52 specifications and application scope

API 5L X52 is a steel grade of API 5L, which specifies the manufacture of two product grades (PSL1 and PSL2) line pipes. X52 line pipes can be made seamless or welded and are widely used as pipelines for oil and natural gas transportation. CSC offers other grades for oil and gas transportation around the world: X42, X46, X52, X56, X60, X65, X70 line pipe.

manufacturing process

Steel ingots, billets, billets, coils or plates for the manufacture of pipes shall be manufactured by alkaline oxygen, electric furnace or open hearth combined with a ladle refining process. For PSL2, the steel should be killed and melted according to fine grain practices. Coils or sheets used for PSL2 piping shall not contain any repair welds.

For welding API 5L x52 line pipe, there are 3 welding types: ERW (Resistance Welding), LSAW (Longitudinal Submerged Arc Welding) and SSAW (Spiral Submerged Arc Welding) welding types.

Hydrostatic test

Pipe to withstand a hydrostatic test without leakage through the weld seam or the pipe body. Jointers need not be hydrostatic tested provide the pipe sections used were successfully tested.

Bend test

No cracks shall occur in any portion of the test piece and no opening of the weld shall occur.

Flattening test

Acceptance criteria for flattening test shall be:

EW pipes D<12.750 in:

X60 with T 500in. There shall be no opening of the weld before the distance between the plates is less than 66% of the original outside diameter. For all grades and wall, 50%.

For pipe with a D/t > 10, there shall be no opening of the weld before the distance between the plates is less than 30% of the original outside diameter.

For other sizes refer to the full API 5L specification.