API 5L 46th ed. Hydrostatic Testing of L450 (5LX65M) 36" x .562wt

[APIpipeWholesaler]

Seeking Hydro of 100% SMYS @ 70KSI yield.

API 5L 46th ed. L450 (5LX65M) PSL 2 36" x .562wt Actual Yield on MTR is 72,300

Mill hydro'd at 2230# for 10 seconds

What hydrostatic test pressure would be required to meet 100% SMYS @ 70KSI yield?

As always, thanx everyone in advance.

-=Fred=-

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1628092823/tips/36_x_.562_MTR_07-27-2021_h31ymo.pdf[/url]


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[1503-44]

P₆₅ = 65000 x 2 x 0.562 / 36 = 2029 psig
P₇₀ = 70000 x 2 x 0.562 / 36 = 2185 psig

Actual yield stress is always somewhat higher than the minimum specified yield stress values of 65 and 70,000 psi.

Test pressure of 100% yield is based on the pipe's minimum specified yield stresses.

 

[LittleInch]

I don't understand.

SMYS means specified MINIMUM yield strength.

Why are you testing at the yield on the MTR.?

"Yield" is not an exact term or test number but commonly taken to be the point where the stress strain graph slope changes by 50%. It will also vary between pipes as will the wall thickness.

So some yield takes place.

Doing hydro that high is not, IMHO, doing you any good and potentially partially straining the pipe.

Mill tests are usually 90% of SMYS to avoid this issue.

But you must know this already?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

Back in the day Northern Natural Gas/Enron tested to 103% of SMYS.
Reason: "The pipe has already been mill tested, this is for testing the welded joints."

I convinced them that they should probably not do that offshore, to which they agreed, but still went about it for onshore work.