local stress

COADE Piping Stress Analysis Seminar Note say"use WRC107 to calculate local stress"(stanchion/bend)page 3-16.Considering WRC107 limits and that it is applicable for cylindrical and spherical, Someone can give me explaination on it? Anyway, I use SIF to analyise on actual job.

Sir,

There is no harm in using SIF of these ASME B 31.3 unlisted components like elbow stanchion or 90 deg trunions; better the SIFs come from some FEA analysis using FEPIPE.

If we have only C2, we can multiply/divide B 31.3 App D SIF/flexibility factor by some safety factor ( say 1.5 or 2), by first getting larger of unreinforced/reinforced tee & bend SIF/flexibility factor from C2.

Perhaps you are discussing about 90 deg trunions, where Coade directive of using WRC-107 for cylindrical shell/nozzle attachment is okay. But, I have seen people using 2.1(max value for fillet weld joint,socket weld flange or fitting SIF in B 31.3 App-D) as SIF in this application, the source of which some experienced forum member may be able to explain to us.

regards,

sam

Hi!Richard,can you tell how to use WRC107 to analyise local stress for elbow with stanchion. Thanks!

Your configuration is "technically" outside the scope of WRC107. The recommended way to evaluate local stresses for an elbow with a stanchion is with the Finite Element method.

For a "quick", "rough" check, you can apply WRC107, but you will have to make a number of assumptions along the way, which could lead to inaccuracies in the results. I apologize for not being more specific, but I can't make these "engineering assumptions" for you.

The Course Notes don't recommend WRC107. What the notes say is "3 - local stresses at the stanchion are only as accurate as WRC107 bulletin". Personally, I don't think the accuracy is there and I suggest you go the FE route.