tube to tubesheet joint and channel/shell flanges pwht

[pastyl]

Hi all
I am interested for the following clarifications

1) According TEMA-R only tubes expanded in tubesheet and back fillet welded are acceptable method or tubes welded with sealing (fillet) weld and groove weld (full strength) (acc. ASME VII UW without being expanded) are also acceptable joint method.

2) Does anybody knows if at any case channel and shell flanges shall be pwht. Using PVElite Code arises the above requirement, even if the thickness and the material of the welding joints does not such as pwht be necessary accor. ASME VII.

 

[metengr]

pastyl;
Are you asking if PWHT is required of the tubesheet or channel head based on tube to tubesheet seal or groove welding???

 

[pastyl]

No
I am asking first if acc. TEMA R welding joint of tubes to tubesheet with sealing and strength weld is acceptable and secondly if pwht is required to the joint of channel or shell flanges to the shell or channel.
The reason is that when at PVElite I insert a body flange it requires to declare the joints as pwht

 

[gr2vessels]

Pastyl,
The strength weld of tubes to the front of tubesheet AND the seal weld of the tubes at the back of the tubesheet is not prohibited in TEMA R, nor is in the ASME, or API 660, then is acceptable. Obviously, there are other problems related to the differential expansion which cracks the seal weld, also the welding procedures, the lot...
The channel/bonnet/shell fitted with girth flange may exceed the thickness required for PWHT (refer UW-40) and that's automatically detected by the PV Elite. In that case you have to declare the joint as PWHT, in order to progress the calculation.
Hope this helps,
cheers,
gr2vessels