Doug,
I get
57psi, 111 feet, for crush depth by external pressure on 10" pipe per the
chart specs you referenced. Did you remember to remove the stiffener
information in the spread sheet? By default, the spreadsheet employs 1.25
inch stiffener web and 1.5 inch stiffener flange. To compare a
common pipe you'd have to remove the stiffener info. The spreasheet
won't accept "0", so change the stiffener info to ".0001" or some ridiculously
small number like that. Then you'll see the difference between internal
and external pressure on the pipe.
Jon
Thanks for your help, Jay and Jon:
Yes this is the right kind of
chart, I just want it to have one more column which would be the working PSI
if the PSI force was external, aka
submarine.
Look at:
http://www.pveng.com/Charts/Pipe%201.03%2020ksi.pdf a 10" steel Schedule
20, .25 wall it shows Max PSI (I think E=1 means no safety margin, right?) of
827. And when if I am using the Hull Calculation sheet right I get 940
PSI for a 10 inch steel hull with a .25 plate thickness. But if I switch
the Young's Modulus of Elasticity to
20,000,000 to match the steel pipe it drops to 845 PSI.
So the PSI of
the 10" steel pipe seems to be the same regardless of the load being internal
or external. So, if that is true, would it hold true for larger diameter
pipe? How about aluminum pipe or PVC or UPVC pipe?
Looking forward to your comments, and
thanks again for your assistance.
--Doug
J