Welding pipe to pressure vessel nozzle
Welding pipe to pressure vessel nozzle
(OP)
If you have a code certified pressure vessel, with a stub pipe coming off the side and bottom head of the vessel, are you allowed to weld a pipe directly to it?
Is this acceptable, or do all connections need to be flanged or screwed into a threaded connection on pressure vessels.
The vessel is approx 18 inches OD x 4 ft T-T
Is this acceptable, or do all connections need to be flanged or screwed into a threaded connection on pressure vessels.
The vessel is approx 18 inches OD x 4 ft T-T





RE: Welding pipe to pressure vessel nozzle
Weld the pipe directly to what? To the pipe stub, like a butt weld? To the shell, for a new nozzle? To the bottom head for a new nozzle?
What is the purpose for welding the pipe to this vessel?
What is the function of the pressure vessel? Pressure?
Are you qualified to perform this work by virtue of having a National Board Certificate of Authorization to Repair Boiler/Pressure Vessels?
RE: Welding pipe to pressure vessel nozzle
A question properly stated is a problem half solved.
Always remember, free advice is worth exactly what you pay for it!
RE: Welding pipe to pressure vessel nozzle
If it needs to be certified as a repair to the vessel we will go with a flanged connection. The tank (vessel) contains 245 fa refrigerant, and we are trying to make it leak free. Threaded connections have leaked on us in the past and thats unacceptable. If we can't weld we'll explore different gasket materials for flanged connections.
RE: Welding pipe to pressure vessel nozzle
RE: Welding pipe to pressure vessel nozzle
For 2" Sch 40 pipe nozzle, it would make better sense to weld versus using a threaded connection. If you are going to butt weld or fillet weld a flange to the existing nozzle on this vessel, you need an R-Certificate issued by the National Board. If you don't have this, hire a repair contractor that is licensed for boiler/pressure vessel weld repair and sub this work to them.
RE: Welding pipe to pressure vessel nozzle
RE: Welding pipe to pressure vessel nozzle
Thanks for the clarification. That's exactly what I needed to hear.
RE: Welding pipe to pressure vessel nozzle
The weld metal and pipe are in the scope of the piping code which you are working to. Yes, it is understood that part of the nozzle (vessel) will be melted and refrozen in the welding process.
jt