Pipe Cap elliptical ratio

[Tony1t]

I designed a vessel with B16.9 pipe cap as head. B16.9 said that the shape of these caps shall be ellipsoidal and shall conform to the requirements given in the ASME Boiler and Pressure Vessel Code. Which elliptical ratio should be indicate in MDR? thkx .

 

[gr2vessels]

You are kidding, don't you? How did you designed a pressure vessel to ASME VIII if you don't know the type/ratio of dished end you were using? You mentioned the ASME B16.9 standard, did you bother at least to check in the standard what shape is the ellipsoidal pipe cap? How do you know the design you made is safe? Do you care?
I can't believe that the forum can tolerate this behaviour and we can be held accomplices to potential unsafe design, by simply answering a naive? question.

 

[bpv66]

I could be wrong but I think all he is asking is what ratio to record on the U Form.

In my opinion I would not record a ratio on the U-Form. UG-44 requires B16.9 to be calculated as straight seamless pipe. UG-27 calculations do not require a ratio to be used in the formulas and B16.9, Table 10 note (b), does not address a ratio.

I've been told that B16.9 pipe caps are not true 2:1 ellipsoidal heads and if that is the case then not sure how you can record 2:1 on U Form.

 

[bpv66]

I could be wrong but I think all he is asking is what ratio to record on the U Form.

In my opinion I would not record a ratio on the U-Form. UG-44 requires B16.9 to be calculated as straight seamless pipe. UG-27 calculations do not require a ratio to be used in the formulas and B16.9, Table 10 note (b), does not address a ratio.

I've been told that B16.9 pipe caps are not true 2:1 ellipsoidal heads and if that is the case then not sure how you can record 2:1 on U Form.

 

[Tony1t]

thanks BPV66

 

[sanshu1111]

ASME B16.9 may not be a true 2:1 ellpsoidal head as indicated by bpv66. I will prefer to mention std cap as per B16.9 instead of mentioning any ratio.

This question will mainly arise when we need to perform any calculation for the standard cap in case of any opening on the same. Any idea if 2:1 can be considered for the same and what will be the basis, any code reference?

Regards

Sanj

 

[SnTMan]

You may a) ask the manufacturer, b) measure it.

Regards,

Mike