Internal Hydro test welded cap

[abehong]

Hello:

I have been working on a large vertical vessel alteration project. The client wants to add a new 12" nozzle on existing vessel. We had a discussion about site hydrotest requirement few days ago. We will have to weld a cap internally to cover up the new nozzle and then proceed hydrotest . It seems to be a tricky design for the welded cap through due to the shape of it . I do not think that standard weld cap will fit in place. It might be some kind special design . Just seek the possibility that someone likes to share the experience with me .

Thank for your consideration

Abraham

 

[gr2vessels]

abehong, are you trying to hydrotest the nozzle only, without testing the altered vessel itself? Can you clarify a bit what are you trying to do?
Cheers,
gr2vessels

 

[abehong]

Hello, gr2vessels:

Yes, We are planning to do local hydrotest on the new nozzle only after fabrication because the size of vessel and some restraints on site , it is almost impossible to do hydrotest on the whole vessel.

Thanks

Abraham

 

[gr2vessels]

I don't think that's going to work;- whatever you weld, it will put a lot of undue stress on the shell at the weld circumference, obviously depending on the hydrotest pressure. If possible, I suggest extend the nozzle neck inside the vessel and weld the cap on that end. After test, remove as much as needed/possible of the internal extension.
Cheers,
gr2vessels

 

[XL83NL]

there are standard solutions available on the market which allow you to locally hydro a nozzle. that should solve your problem.
as an example (found this through google in few seconds);

http://carber.com/services/nozzle-testing.html