Specific Modern Flange Design Question

[Gorpomon]

Hello,

I'm using Modern Flange Design Bulletin #502 from Taylor Forge for Full Faced Flanges, using the worksheet on page 14. If anyone has any experience using this document I have a question about two of the equations. On page 14, in section 4 "Load and Bolt Calculations" the equation for H'gy and Wm2 read:

H'gy = (hg/h'g) * b * pi * G * Y = 48,555
= (1.325/.633) * 1.375 * 3.14 * 26.85 * 200 = 48,555

Wm2 = (b * pi * G * y) + H'gy = 23,196
= (1.375 * 3.14 * 26.85 * 200) + 48,555 = 23,196 ???

Clearly, if H'gy is 48,555, and you only add the b*pi*G* value to it, how can it reduce down to 23,196? Seems like an error to me, but I might be missing something.

Furthermore, if you just resolve the first part of Wm2 and ignore the H'gy part, you get:

Wm2 = (b * pi * G * y) = 23,184 (by my calculator), close enough to what the handbook says.

So is that H'gy an error in that spot? If it is, then what is its use?

Has anyone resolved this in the Taylor forge handbook?

I realize this is specific, but has been bugging me for sometime, so I figured I'd ask it here. Any help is greatly appreciated!

 

[Canadieng]

For what it is worth:

In Structural Analysis and Design of Process Equipment - 2nd Ed - Jawad and Farr:

On page 312, there is a worked out example of the same calculation sheet, with different numbers.

There H'Gy = 443,496 & Wm2 = 619,186

Without looking at it more, this would imply that the example numbers in the Taylor Forge 502 bulletin are wrong/typoed.