Dear all

We are having a U bundle exchanger with channel side integral with tubesheet; Tubesheet is with a lip and hemispherical head is welded to the lip.

4-18-4 para c of of ASME Section VIII Div2 imposes a condition that the head shall be directly welded to tubesheet and no cylindrical shell shall be welded in between; Similar condition exists in ASME Sec VIII Div1 (UHX - 10 b)

My personal interpretation is the lip of short length (machined from tubesheet) is not a cylinder and the intention of code is not to weld a separate cylindrical shell in between. Hence welding the hemispherial dished end without any cut back to the lip of tubesheet should be OK.

The job is not code stamped ; We would like to have your expert opinion on the issue please


Thanking You and with regards

_________________
R.SRINIVASAN
Sr. VICE PRESIDENT
Head, Design and Engineering
PED,ISGEC,
YAMUNANAGAR
HARYANA -135001
INDIA

I agree with your interpretation.
Mauro