CROSSED LINK BETWEEN UG-36 AND UG-39? 1

[nachocivicos]

Hi,

In case of openings in flat heads, I am not fully sure of the logic linking UG-36 and UG-39 in ASME VIII Div. 1. As a first "general" appearance in the "OPENINGS AND REINFORCEMENTS" subject, one could think that openings meeting UG-36 requirements do not need to be further checked for reinforcement, and that´s all. But later, when reading UG-39 (a), one more requirement "do not exceed one-fourth the head diameter or shortest span" appears, and hence openings meeting UG-36 requirements but exceeding that one-fourth limit would still need reinforcement calculations according to UG-39.

Furthermore, would all the rules for multiple openings apply as far as only one of the openings in a group of three fails to meet size requirements? At first glance I think "yes" but again, perhaps is it a too-much conservative point of view?

I try to illustrate it with my proposed interpretation in the attached PDF for multiple openings. Am I right? Could anyone confirm or add some more info?

Many thanks in advance,

J.I.G.C.
Chemical Engineer

 

[unclesyd]

You might want to take a look at this document. Look at page 20+. This is simplification of what I think you are trying to do.

http://www.pdhonline.org/courses/m205/m205content.pdf