Hydrostatic Test in Tanks designed to API 650

[leont]

After change a nozzle in a existing atmospheric Tank, is mandatory to carry out a Hydrostatic Test???.

Around the new nozzle we can see shell deformation as a bulge that could input stress concentration in weld Joint between nozzle and the shell.

It is mandatory once we have detected the bulge or it is mandatory according codes API 650 / API 653 each time you replace a shell nozzle..?

Thanks a lot in advance

 

[IFRs]

Please read API 653 for when a hydrotest is required. It is very clear on this subject.

 

[Bonswa]

I disagree. You have to get an older version of 653 to find the criteria. It used to be clearly stated, however now it's not.

 

[JoeTank]

Bonswa,
Now I disagree. Get a copy of the curent version of API-653 and read 3.20(a) and (b) regarding nozzle sizes that constitute a major repair/alteration that reequires a hydrotest.

Joe Tank

 

[Bonswa]

Ahh... sorry for that. for some reason I had 3.2 stuck in my head and not 3.20. When I looked up 3.2 and saw "definition deleted", i thought that maybe they deleted that information you needed. However, i was looking in the wrong area. 3.20 is EXACTLY what you need.

Thanks Joe. Sorry IFR.

 

[leont]

Thanksa lot guys. I know what API 653 state about it, however I would like to know anything else, since Codes state the minimum requirements to be accomplished

 

[786392]

Dear Hello/Good Morning,
I feel your understanding might be correct,but this could be the 'Optimum value'indeed!

Best Regards
Qalander(Chem)

 

[API123]

If you are in need to evaluate the stresses on the nozzle relative to your deformation in the shell, you may want to look into part 8 of API 579.