Welding Pad plate after Hydrostatic Test 1

[Merzi]

we have hydrotested a Heat Exchanger( 20" Dia) later on we welded a pad( fillet weld) on the shell to support a pipe.

Do I have to test the Exchanger again because of the fillet weld. Or if we do an NDT like PT ot MT will that suffice

Merzi

 

[Rich2001]

You welded on a pressure containing member, changing the microstructure of the material (grain growth), diluted the base material with filler material and induced additional stresses due to the welding process. What makes you think that you would not have to rehydrotest the vessel?

Vita sine litteris mors est.

 

[kukes1954]

without having more details such as code of construction,new construction or a vessel already in service,material,thickness,pwht requirements,etc.,i would suggest that you discuss this with your A.I. of record or the local jurisdiction as applicable.

 

[metengr]

You need to provide more information – what is the code of construction? If the vessel was built to ASME B&PV Code, hydrotested, and the AI signed off the data report as having completed construction, yes, you might be able to avoid having to re-hydrotest the vessel. This could be treated as a repair under the National Board Inspection Code requirements.

However, if the vessel was hydrotested and the AI did not complete the data report for the vessel, it would need to be re-hydrotested.

 

[PAN]

Merzi,
You said, weld a pad to support a pipe. In my undestanding, there will be additional external load to the shell.
- What is the size/load of pipe to be supported by this exchanger?
- What is the welded plate thickness?
I do not know the code. However, in my company, we will not allow to weld the pressure vessel for pipe support (except special case).