With the increased use of pressure vessels, pipelines and piping systems, more and more pipes are being put into use. Mechanical damages in the form of dents and cracks occur frequently. These damages are mainly caused by 3 party or operation activities, fabrication errors etc.

Typical defects that may found in the pipeline systems include:

Multiple cracks often occur in offshore pipelines through the development of fatigue cracks, girth weld defects during offshore construction and pitting  corrosion.

There are several type of cracks on offshore pipeline:

Pipeline suffered bent and cracks that usually occur because of external pressure hydrostatic, axial compression, bending applied, or a combination of all of them. It usually occurs during installation.

Pipe rupture or tear because of the bend pipe and high pressure in the pipes that lead to a crack pipe and then rupture / tear

Pipes leak that lead to the appear bursts of fluid in the pipe due to the big internal preassure from inside of pipe.

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Source:

Bai, Yong and Bai, Qiang. Subsea Pipelines And Risers. USA: Elsevier Inc. 2005.

http://www.eng.nus.edu.sg/cee/updates/seminar/27072015.pdf