Section VIII, Div.1, UG-39

[Bangrod]

If a bolted flat head with multiple openings is reinforced per UG-39(e)(2), does it also have to be reinforced per UG-39(d)(2)?

My thinking is that UG-39(d)applies to flat heads with a single opening, while UG-39(e)applies to flat heads with multiple openings, so it seems to me that only the UG-39(e) reinforcement would be applicable and would be added to the required thickness from UG-34(c)(2).

THANKS

 

[vpl]

Section UG-39(e)(2) is used to calculate the reinforcement thickness using the formulae in UG-39(d) as modified by a factor, h. So you aren't adding both thicknesses, you're using the formulae modified from UG-39(d) to calculate the thickness required for UG-39(e)(2).

Patricia Lougheed

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[Bangrod]

Thank you Patricia. Now that I read over UG-39 again, I see what you are saying with regard to modifying the formula from UG-39(d) by the h factor from UG-39(e)(2).

I have another application that is similar, except that it is being designed to ASME Section I. It appears to me that the ligament section of PG-52 is different from the reinforcement requirements in Section VIII in that it does not use an 'h' factor, just a ligament efficiency. In this case, would the flat head thickness from PG-31 be divided by the ligament efficiency to determine the total reinforced thickness requirement?

I appreciate any input you can provide.

Thanks,
Mike Bange