jacketed vessel design
jacketed vessel design
(OP)
If you have a jacketed vessel and the internal vessel is operates under full vacuum (15 psi external) and the water jacket has 35 psi internal would the internal vessel be required to have a external design pressure of 50 psi or 35 psi based on the pressure in the water jacket?





RE: jacketed vessel design
I think its needs a design pressure of 50psi externally as your pulling a vacuum on the inside and pressure from the water jacket is 35psi.
hope this helps
RE: jacketed vessel design
However it is not impossible that the internal vacuum is never concurrent with the jacket pressure, so that they are not to be superimposed. Note by the way that I've never met such a condition and that it would need to be clearly specified in the design conditions for the vessel.
prex
http://www.xcalcs.com
Online tools for structural design
RE: jacketed vessel design
To my opinion it is absolutely clear that the external design pressure should be of 50 psig, it is NOT unusual condition requirement. However, even though process engineer clearly defines that process requirements never combine internal vacuum and external heating / cooling, your design conditions have to take into account the possibility of control or operating failure.
Good luck.
RE: jacketed vessel design
What do the U1 from the National Board say?
Leonard@thill.biz
www.thill.biz
RE: jacketed vessel design
it may be easier to consider all pressures in terms of absolute. The description mixes absolute pressure and gauge pressure. The Jacket sees 35psig (gauge), and the vessel sees -14.7 psi gauge (i.e 0 pressure absolute). So if all pressures are read as absolute then the jacket vessel sees 35+14.7=50psi on its internal face and (35+14.7)-14.7(due to atmosphere)=35psig on its external face.
RE: jacketed vessel design
So, in my opinion, the design pressure should be 50 psig on inward faced members and 35psig on outward faced mambers unless process engineer or customer clearly specifies that the vacuum and 35 psig of jacket doesn't concur. It seems to be very unlikely that they would specify so, though.
kyong
RE: jacketed vessel design