Dear All,
Can you explain the requirements, if the hub thickness of flange is higher than the pie wall thickness being joined.(pipe thickness is 19.05mm and flange hub is 28.5mm, but actual thickness is 19.05)
1. is it required to do preheat during welding (because flange hub is higher than 25mm)
2. How about WPS thickness range ,,?(is it need consider the flange hub thickness is as maximum thickness..?)
I assume you are referring to a slip-on or socket type flange. That being the case, the welds are fillet welds.
With regards to preheat, I would use the thickness of the thicker part being welded.
For fillet welds, the range of thickness is not the same as it is for groove welds if I recollect, but that is something you can easily look up in Section IX.
Al
Thanks for your reply............
This is not slip on flange , it's 36" sch 40 single bevel (Groove weld)
So, its a weldneck flange?
You can take a look at B16.25 for the weld details you should be using and how to address the mismatch or different wall thickness of the pipe and the flange.
Al
Dear....
Ya it's weld neck..........
B16.25 is for end preparation.........when you refer B16.47 from Fig-1 to Fig-3, you can see something related to my question, but it's not cleared to me fully.........so i want know anybody's previous experience if have.
For dissimilar wall thickness weld details please refer Fig 434.8.6-2 of B31.4 regardless of piping codes. For CS materials, PWHT is required only if the thickness exceeds 32 mm as per B31.8 sec.825.
Forum