external pressures on vacuum vessels
external pressures on vacuum vessels
(OP)
I have been asked to build a vessel out of 30" schedule 40 carbon steel pipe, that will be 36" tall and sealed at both ends. The cylinder will be placed under a vacuum in excess of 29" hg. at an operating temperature of less than 200 degrees c. Even if an absolute vacuum could be achieved, the external pressure would never exceed 15psi at sea level. The wall thickness of the pipe is 3/8" and I would think it capable of handling such a load, but I can not find a formula to prove it to myself. Your comments would be appriciated.





RE: external pressures on vacuum vessels
RE: external pressures on vacuum vessels
RE: external pressures on vacuum vessels
RE: external pressures on vacuum vessels
Be sure of your materials specification. I have designed a built many vacuum vessels. None used carbon steel, all were fabricated of 304 Stainless steel. Based upon your inital statements .375 is more than enough wall thickness, however do consult with ASME Section VIII, Div.1 with sub paragraphs as suggested by "TGS4" and "codeeng". If this is for an aerospace application it will not be acceptable if carbon steel is used.
Be sure.
Best regards
pennpoint
RE: external pressures on vacuum vessels
RE: external pressures on vacuum vessels
You should also recheck yourself using the code appropriate to your own country as you are the designer and need to document your calculations - as pointed out by others.
Naresuan University
Phitsanulok
Thailand
RE: external pressures on vacuum vessels
Larry