UW-12(d) interpretation
UW-12(d) interpretation
(OP)
How should UW-12(d) be interpreted for an ASME CODE heat exchanger that has a seamless tube side (cup forging) with a bolted cover and welded nozzles (welded shell side)? (The cup forging is an integral tubesheet/shell/flange on the tube side, with a shell welded to the shell side of the tubesheet).
It would be my understanding that the effeciency (E from UG-27) would be = 1 (for the tube side only), since there is no welding on the cric. and long. "seams" (no welding of a head), thus the seamless vessel section does not need to meet the UW-12(d) requirements. (The shell side circ. seam would meet the applicable UW effeciency.)
My concerns would be if anyone could interpret this any other way, or if there would be any exceptions.
It would be my understanding that the effeciency (E from UG-27) would be = 1 (for the tube side only), since there is no welding on the cric. and long. "seams" (no welding of a head), thus the seamless vessel section does not need to meet the UW-12(d) requirements. (The shell side circ. seam would meet the applicable UW effeciency.)
My concerns would be if anyone could interpret this any other way, or if there would be any exceptions.





RE: UW-12(d) interpretation
muld0020,
I'm not entirely sure I understand the design you describe, but for seamless tubing which does not contain the welds described in UW-11(a)(5)(b) the requirements for spot radiography in UW-12(d) would not apply and would allow E = 1 for you circumferential stress calcs.
Regards.
RE: UW-12(d) interpretation
RE: UW-12(d) interpretation
Question: is your exchanger TEMA Type DEU heat exchanger one pas shell side, two presses tube side
TUVE SIDE: PRESSURE?
RE: UW-12(d) interpretation
This is a hypothetical situation so you can assume the following:
Tube side = 3000 psig
Shell side = less than tube side
Sec. VIII Div 1
Material of Tube Side (Tubesheet/Channel Barrel) = SA350 LF2 Cl.1
Material of Shell Side (Shell) = SA516 Gr70
I just want to cover my bases and be certain that choosing E = 1 correct and justifiable.
RE: UW-12(d) interpretation
Regards,
Mike
RE: UW-12(d) interpretation
RE: UW-12(d) interpretation
E = 1 for the channel shell.
The tube sheet ligament efficiency will be per Part UHX for tubesheets integral to channel and shell.
If the shell side is seamless (or welded pipe) with a headed attached with a Type 7 joint, as it appears it is welded to the tubesheet by a corner joint as well, then E would also be 1 regardless of SRT to UW-11(a)(5)(b).
Regards.