Joint Efficiency for Seamless Hemispherical Dished End
Joint Efficiency for Seamless Hemispherical Dished End
(OP)
We are having a case where,
Hemispherical Dished End = Seamless
Hemispherical Dished End to Shell Joint = No radiography
We have three queries:
1. As this Hemispherical Dished End to Shell welded joint is of Category-A, neither clause UW-11(a)(5)(-b) nor UW-12(d) will be applicable. Is our understanding correct?
2. What Joint Efficiency shall be considered for calculation of thickness for Hemispherical Dished End in this case?
3. PVElite software consideres following for Hemispherical Dished End : (File Attached)
a. Longitudinal Seam Efficiency = 0.85
b. Circumferential Seam Efficiency = 0.7
However, considers values of E = 0.85 in Design Calculations. Is that correct?

Please advice.
Thanks.
Hemispherical Dished End = Seamless
Hemispherical Dished End to Shell Joint = No radiography
We have three queries:
1. As this Hemispherical Dished End to Shell welded joint is of Category-A, neither clause UW-11(a)(5)(-b) nor UW-12(d) will be applicable. Is our understanding correct?
2. What Joint Efficiency shall be considered for calculation of thickness for Hemispherical Dished End in this case?
3. PVElite software consideres following for Hemispherical Dished End : (File Attached)
a. Longitudinal Seam Efficiency = 0.85
b. Circumferential Seam Efficiency = 0.7
However, considers values of E = 0.85 in Design Calculations. Is that correct?
Please advice.
Thanks.
Ashay Kadam
Mechanical Engineer
India.





RE: Joint Efficiency for Seamless Hemispherical Dished End
RE: Joint Efficiency for Seamless Hemispherical Dished End
The Circumferential Joint Efficiency is based on the weld between the dished end & the shell. As you have not carried out any radiography, this should have a Joint Efficiency of E = 0.7. Carrying out spot radiography on the welded joint would allow you to use E = 0.85, and if you carried out 100% radiography you could use a joint efficiency of E = 1.0.
RE: Joint Efficiency for Seamless Hemispherical Dished End
I just referred the solved example no. L-1.5.3 (d) of Appendix-L from ASME Sec. VIII Div. 1 (2011 Add.) & found your reply in line with it.
Refer attachment:
Ashay Kadam
Mechanical Engineer
India.
RE: Joint Efficiency for Seamless Hemispherical Dished End
In addition to the above noted, you can see the following link: http://www.pveng.com/ASME/ASMEComment/WeldEffic/We...
El que no puede andar, se sienta.
RE: Joint Efficiency for Seamless Hemispherical Dished End