GBENARD
Specifier/Regulator
- Dec 12, 2003
- 13
We have some problem. ASME code seems to allow the use of welded headers (A387 91) as well as seamless pipe (A335 P91) for the manufacturing of headers for boilers. Even if it seems, from some studies, that we can expect a more significant creep-fatigue interaction for 91 in HAZ than from 22 material, as well as some reduce impact strength for welded pipe in from of seamless, we have no definite statement for the advantage of the use of seamless headers against welded pipe headers. I should add that this is concerning HRSG designed for a baseload service, something like 20 cold start up per year for a 25 years design life, the headers working at 565°C/130 and 30 barg.
Is there anybody knowing of a serious study on that problem or having experience on that matter (in that case, for how long because my concern is the long term)?
Is there anybody knowing of a serious study on that problem or having experience on that matter (in that case, for how long because my concern is the long term)?