Testing of vessel 1

[welder007]

I have a vessel tetsed at 75 bar which has an inbuilt coil.The coil has been tetsed at 15 bars.The vessel has(designed to Sev VIII Div 1- not certified)undergone a minor repair by welding(no alteration) at one of it's nozzle. If i pressure test the vessel at 75 bar, will it affect the coil's integrity? any other way to avoid pressure test the vessel?it has been 100% radiographed.Closure weld procedure did not follow during repair.

 

[gr2vessels]

welder007,
If the vessel was designed to ASME VIII, then the coil has been designed to take 75 bar external pressure, even if it was tested for internal pressure of 15 bar. What makes you think that making a small repair on a nozzle, you'll affect in any way the coil? Hang on, did you alter the coil nozzle?? If not, you go ahead and test it again, as you already did that previously.
Cheers,
gr2vessels

 

[welder007]

Thanks gr2 vessels
No repair work carried out at coil nozzle , your answer clarified me.

 

[metengr]

You did not need to pressure test, period. Depending on the type of nozzle repair nondestructive testing could have been performed in lieu of pressure testing. All you need to do is to confirm the integrity of the weld repair provided no alteraiton was performed. Pressure testing is not needed unless NDT cannot be performed.

 

[JR97]

Welder007,

Can you manifold the coil and vessel inlet piping together. During the test the coil and vessel will be at the same pressure (except the inlet portion of the coil) so no stress on coil?

JR97

 

[welder007]

metengr
That vessel was 100% radiographed and hydrotested on construction.If hydro test can be waived then pls provide me the code referance.

JR 97
The coil and vessel has been tested at diiferent pressures (coil 15 bar and vessel 75 bars).So ican't test both at the same pressure.

 

[metengr]

API 510 or National Board Inspection Code deal with requirements for in-service vessel weld repairs. As I stated, for a vessel that has been placed into service there is no need for repeat hydrotesting after weld repairs.