Help me understand Thin wall Pressure vessels 1

[ed72073]

I don't know if this is the correct area for my question, but I am trying to understand what is considered a thin wall pressure vessel. First I am no expert in any way, and this site has more information that I can even understand at times, but I know I should be able to have my questioned answered with all the knowledge of people on this forum.

My understanding is a thin wall pressure vessel is calculated as such, Diameter of outside tank, divided by the wall thickness, should be greater than or equal to 20, Is this correct? So my example is I have a pressure vessel that has an OD of 24" and a wall thickness of .250" is calculated to 96 an fits the formula of a thin wall pressure vessel, or am I not correct?

24 / .250 = 96
96 > 20

 

[fegenbush]

24" Diameter x 0.250" Wall thickness definitely falls under the Thin Wall Assumption. The idea of the this assumption is that the membrane stresses are much larger than the bending stresses, and thus control the design. The assumption becomes invalid at R/t = 10 when the bending stresses begin to control. Further explanation of the assumption and derivation of the limit can be found in common reference texts such as Mechanical Engineering Design by Shigley and Mischke.

 

[ed72073]

Thank You with your responds, I was think based on the formula it falls under a thin wall vessel, but I was unclear ant not sure that is why I asked. Basically all the others that are larger diameter with the same wall thickness would still be a thin wall vessel, assuming the formula of R/t > 20.