Sec. VIII Div. 1...L-1.6

[dtn6770]

Example L-1.6 in Appendix L (page 551) cites an equation for a 2:1 ellipsoidal head.

t= PD
2SE+0.4P

Is that equation correct?
I only ask because I have not found it elsewhere in the Code. The equation resembles

UG-32(d)
t= PD
2SE-0.2P

and

UG-27(c)(2) applicable if the long. stress of a head to shell cir. weld is being considered.
t= PR
2SE+0.4P

What are the chances the the author of this example goofed? It's more likely that I'm missing something but I figure it's worth asking.

 

[vesselfab]

NO 1 is correct for an o.d. head

NO 2 is for o.d. hemispherical head

N0 3 is o.d. circumferential seam

if your vessel is id...they are different

pick up a pressure vessel handbook

spells it out clearly

 

[dtn6770]

I’m disappointed vesselfab.

I had picked up my Pressure Vessel Handbook and it offers the following for a 2:1 ellipsoidal head in terms of outside dimensions

t= PD
2SE+1.8P

That equation is the same as what's derived from Appendix 1, 1-4(c) and IS NOT the first equation, as you suggest, that I listed above from the L-1.6.1 example.

That same handbook offer this for a hemi. head (OD)

t= PR
2SE+0.8P

Which IS NOT the second equation I listed above.

Lastly, the third equation I listed above is for what I stated in terms of inside dimensions and IS NOT for an OD circumferential seam as you suggest.

I guess what we can agree on is that the handbook does spell most of these equations clearly.

 

[vesselfab]

ok

i messed it up

 

[dtn6770]

$hit happens...no blood, no foul.