cyclic design limitations to lower pressure rated vessels

[Tony Hines]

If a standard carbon steel vessel with 150 series flanges is operated at max pressure of 75 psi down to a vacuum in a cyclic non-corrosive gas environment of 350,000 cycles per year, at atmospheric temperatures ranging from 0F to 110F, must the vessel have an ASME VIII Div 2 stamp or can it have a Div 1 stamp? Is it possible to have a Div 1 stamp that because of the low operating pressure range that unlimited cycles is possible?

 

[SnTMan]

Tony Hines, per Div. 1, UG-22 cyclic loading must be considered in design however, Div. 1 contains no specific design rules for cyclic loadings. Presumably one would need to apply some form of engineering analysis under U-2(g).

But, yes, a vessel subject to cyclic loading may be stamped to Div. 1.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[TGS4]

With that number of cycles, you will need some type of analysis. Unless your design pressure (and hence your thickness is based on) a pressure of at least 450psi, you will need some description of evaluation. U-2(g) should point you in the direction of VIII-2, but your vessel would otherwise be stamped to VIII-1.