ASME Sec. I External Pressure Calculation
ASME Sec. I External Pressure Calculation
(OP)
Dear all,
Can anybody help me with Section I calculation?
In PFT-51.1.2, the code describes the method for evaluation of the maximum allowable external working pressure, which is just like Sec. VIII procedure. However, in the case of a cylinder with definite pattern openings, what consideration should I use to consider these openings? Should I include the ligament efficiency?
Best regards.
Can anybody help me with Section I calculation?
In PFT-51.1.2, the code describes the method for evaluation of the maximum allowable external working pressure, which is just like Sec. VIII procedure. However, in the case of a cylinder with definite pattern openings, what consideration should I use to consider these openings? Should I include the ligament efficiency?
Best regards.





RE: ASME Sec. I External Pressure Calculation
Of course you won't find the rules for that in ASME I, and even ASME VIII doesn't treat, if I recall correctly, the case of openings in a definite pattern under external pressure.
The point is that ASME VIII requires for external pressure 50% of the reinforcement for internal pressure, but I wonder whether this can be straightforwardly applied to patterned holes. However, if you can provide 100% of the reinforcement as for internal pressure (the required thickness being still determined for the external pressure) you'll be OK.
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RE: ASME Sec. I External Pressure Calculation
RE: ASME Sec. I External Pressure Calculation
What I suppose I would do:
1)Calculate the required thickness per UG-28
2)Consider each hole in the pattern as an isolated opening by setting the limit of reinforcement equal to half the minimum distance between holes
3)Calculate the required reinforcement per UG-37 (50% of the value required for internal pressure)
4)Check that the extra thickness in the wall is sufficient for compensation.
prex
http://www.xcalcs.com : Online engineering calculations
http://www.megamag.it : Magnetic brakes for fun rides
http://www.levitans.com : Air bearing pads