Torispherical Crown radius

[Jugal rana]

As per ASME UG-32, (d) states that inside crown radius equals outside dia of skirt. But how to calculate outside dia without known thickness. Appreciate your help on this....

 

[JStephen]

Assume a thickness, calculate OD and inside crown radius, then recalculate the thickness. Repeat if necessary.
In many cases, it is the OD of the vessel that is fixed, not the ID.
There are some alternate formulas in Appendix 1 also.

 

[marty007]

Just be sure to consider ASME interpretation VIII-1-86-175:

Interpretation Number : VIII-1-86-175
Question(s) and Reply(ies):
Question (1): Does a torispherical head satisfy Code requirements if the inside crown radius exceeds the outside diameter in the corroded condition but meets the requirement of UG-32(j) in the noncorroded condition?

Reply (1): No; see Appendix 1-4.

Question (2): If the answer to Question (1) above is no, which paragraph of the Code should the thickness of the torispherical head be calculated?

Reply (2): The torispherical head must meet the requirements of UG-32.
​

To meet this requirement, the inside crown radius of your torispherical head should not exceed: Crown ID = Head OD - CA

 

[Jugal rana]

Thank You, Gentlemen's for your reply..