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Line Pipe 30in : Collpase Resistance, Internal Yield (Burst) and Tensile Yield
09 December 2017

I Need your Help about the following Line Pipe, I don't found its mechanical Properties

Line Pipe  : OD 30in, Thickness 9.52mm API 5L GR B Spiral Welded pipe

Collpase Resistance : .............psi
Internal Yield (Burst) : : ............. Tonnes
Tensile Yield: .............psi

4 answer(s)
Consultant [retired Shell staff]
Total Posts: 248
Join Date: 02/09/05
It looks like it is a LinePipe to be used as casing. This should be looked at with extreme care as only IF YOU USE Casing acceptance criteria, the linepipe can be considered fit for purpose.

Burst is perhaps the only indication you could trust. The collapse depends on roundness which is not typical of LinePipe, more oval than round.

Furthermore, you must watch the week point i.e. the acute angle of the spiral weld when it meets the orthogonal weld of the flange. Normally it either leaks or will leak soon after.
Drilling Engineer
Sonatrach Petroleum Corporation
Total Posts: 32
Join Date: 24/09/14
Excel File to Calculate Elsatic Collpase Resistance (psi)
Documents uploaded by user:
Elastic Collapse.xlsx
Drilling Engineer
Sonatrach Petroleum Corporation
Total Posts: 32
Join Date: 24/09/14
Thanks all Lot Olango , I patriciate your advise
Well Engineering Consultant and Instructor
Olango Consulting
Total Posts: 21
Join Date: 23/03/16


Looks like your conductor is made from B grade steel plate which is welded spirally into a pipe shape. Not sure that this is in compliance with API 5L would recommend that you check with the pipe supplier as to what steel has been used to make this pipe

The specification of B grade steel pipe is that it has a minimum tensile strength of 50,000 psi (see ASTM Spec for grade B carbon steel).

Pipe has an OD of 30 and an ID of 29.25 so you have a high D/t ratio (large OD with thin wall) That gives you an D/t ratio of 80

Using the API 5C3 calculations

50,000 psi yield strength with a D/t ratio of 80 gives you

burst pressure of 1090 psi

collapse pressure of 94 psi

Tensile strength of 1,744,000 lbs

Very low collapse is a result of the large OD to wall thickness ratio.


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