Performing NDT in lieu of hydrotest
Performing NDT in lieu of hydrotest
(OP)
We have a waste heat boiler for new sulfur recovery unit. This equipment is in 3 sections. Boiler, reaction furnace and burner section. Boiler and reaction furnace are manufactured by one manufacturer and welded together and hydrotest at shop. Burner section is manufactured separately and hydrotested. At site first 2 sections are already erected on foundation and now the burner section is being erected. After erection both section need to be welded together so there will be one circumferential joint joining the burner section and boiler + reaction furnace section.
Now my question is that is it mandatory to perform hydrotest of this field weld joint. If we do so then the other parts will be rehydrotested , would this be a problem. Is there any way we can waive off hydrotest and perform other NDT testing only.
Now my question is that is it mandatory to perform hydrotest of this field weld joint. If we do so then the other parts will be rehydrotested , would this be a problem. Is there any way we can waive off hydrotest and perform other NDT testing only.





RE: Performing NDT in lieu of hydrotest
I have not seen this done before, but I have heard it brought up as an option a few times. I imagine someone here will have a direct reference for you.
RE: Performing NDT in lieu of hydrotest
Do NOT perform that final closure weld until you have agreement from the appropriate parties. In addition to post-weld NDE, there will likely be some additional in-process inspection that may need to be witnessed.
RE: Performing NDT in lieu of hydrotest
RE: Performing NDT in lieu of hydrotest
RE: Performing NDT in lieu of hydrotest
Richard
RE: Performing NDT in lieu of hydrotest
I appreciate vessels are different, but that's my experience of these things.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Performing NDT in lieu of hydrotest
1) The equipment does not have drain nozzles, so how the hydrotest water will be drained?
2) The foundation design was on operating weight only, so if we fill the equipment with water the foundations will fail.
For 1st point I checked the drawings and visited the site also and found 4 No, 2" nozzles at the bottom of equipment, which I think can be used for draining the water.
For 2nd point I doubt the foundation is only designed for operating load, so I have requested the contractor to provide the design calculations for the foundation to verify the same. If this comes out to be correct then I think there is no way to do the hydrotest. So is this case can we go for pneumatic test instead of going for NDT.
Also a good point is mentioned above to contact the authorized inspector in this regards.
Thankyou.