PWHT
PWHT
(OP)
Hi All,
My question is related to our Deaerator vessel(ID=3800mm,TL-TL=15500mm, thk=12mm, Temp.=119c, P=1.9barg)
Based on our process data sheet,PWHT shall be applied for vessel, but our subcontractor does not want to consider PWHT and explains that if they perform PWHT the vessel will be defomed because its thin shell plate.please let me know your idea about this matter.its possible to perform PWHT for this vessel?
Thank you
My question is related to our Deaerator vessel(ID=3800mm,TL-TL=15500mm, thk=12mm, Temp.=119c, P=1.9barg)
Based on our process data sheet,PWHT shall be applied for vessel, but our subcontractor does not want to consider PWHT and explains that if they perform PWHT the vessel will be defomed because its thin shell plate.please let me know your idea about this matter.its possible to perform PWHT for this vessel?
Thank you





RE: PWHT
Yes, PWHT of the vessel can be performed in sections or stages of the vessel with resistance heating elements. The entire vessel would need internal bracing as temporary support if you were using a large furnace.
RE: PWHT
I'm fully satisfied by your explanation
RE: PWHT
RE: PWHT
I don’t know the status of the recommendations that came out in the 80's concerning the construction, inspection, and repair of deareators after several fatal incidents involving same. I do know that when we replaced a unit in the mid 90's it did have a PWHT. There must have been some pretty sound reasoning as I recall there was no screaming and hollering about carrying out the PWHT.
There was quite a lot of information published about the failures.
http
Here is a little information from the web.
http://
RE: PWHT
and Correction of Deaerator Cracking) that may be of use to you. The deaerators in my plant are all PWHT.
~NiM
RE: PWHT
We have included this recommendation in the NBIC Part RB because of reported cases of environmentally assisted cracking (EAC) after weld repairs to these vessels located at or below the waterline.