RE: Secondary creep laws

>Hello Babara,

were u able to complete your creep life study. mind sharing it. im interested because of the failure mechanism of our ethylene furnace heater tubes(we're using a HP-40 mofified alloys) is due to creep and carburazation.

several years back, operation has also operated our boilers way above the 750def F threshodld for CS pipe. The result is the expansion of our 24" main steam header way above the design (as much as 2 feet compare to a computed movement of 13" max). i figure that because creep has set in, i may not be able to pull the piping back to its original location and may have to modify the expansion loop during the steam outage. the algor stress analysis that we've run does not look good. i really hate to mess around with the main header - the resources required to perform the modification and hydro is a nightmare.

> I am undertaking a creep life study for a steam line on a refinery.
>
> I have completed the pipe stress analysis using PSA5 and have the
> pipe moments and forces from the BS806 Hot Stress case (DW + Pressure
> + Thermal expansion).
>
>
>
> Barbara James
>
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Received on Tue May 29 05:17:00 2001