Remedial Action!!!!!

[FAHADRANA]

Dear Experts;
In the picture attached below shows the distance between the CS & nozzle weld toe is very less than the actual required, as thumb rule the distance between the weld toe shall be a minimum of 1.5 to 2 times wall thickness of the shell plate. But it looks less than that, it is approximately 10mm or less.
Even though as per ASME standard Clause PW-14 or UW-14 opening can be located on Welded joint providing that all NDT fully accomplished but it is the thumb-rule for pressure vessel fabrication to maintain a minimum of 1.5 to 2 times wall thickness of the shell plate. There is a metallurgical reason for this requirement, due to less weld toe gap (overlapping) in the Heat Affected Zone fatigue performance of the shell will affect and it will tend to harden the base metal and result in losing the ductility of the metal. It will also affect high opposed tensile stress applied to the narrow member between the welds due to weld shrinkage of the adjacent welds.
Please propose remedial action for the effect on pressure vessel due to the change in metallurgical properties like hardness in HAZ, fatigue impact and excess tensile stress in the narrow member.

Construction Code: ASME SEC I 2019
Stamp Required: Yes (S-Stamped)
Shell Thickness: 45mm
Nozzle Thickness: 10.97 mm
PWHT: Yes



M.FAHAD RANA
WELDING ENGINEER

 

[Dhurjati Sen]

There is no picture !

Check the hardness of the weld, HAZ and base metal. If they are within limits, you are good.

DHURJATI SEN
Kolkata, India

 

[DekDee]

If you are a Welding Engineer you should be proposing remedial action yourself - not asking for advice on an internet welding forum.
And forget about this "thumb rule" - if it is a critical measurement it will be noted in the applicable code.
If it is not noted and you consider it relevant it is your job as the Welding Engineer to ensure it is in the Project Specifications.

 

[weldstan]

The vessel is subject to PWHT. Why are you concerned? There is no "thumb rule" in ASME I.

 

[FAHADRANA]

Thanks Dhurjati sen , sure i will.

M.FAHAD RANA
WELDING ENGINEER

 

[MJCronin]

You have a question about violation of a "thumb rule" that no one in the West has ever heard of and is not part of any ASME code ?

Is that how pressure vessels are built in your country ???.... By just "common knowledge", "thumb rules" and "recent rumors" ?

DekDee and weldstan give good advice above ....

MJCronin
Sr. Process Engineer

 

[weldstan]

Your concern about opposed tensile stress on the membrane between welds is essentially eliminated by PWHT. Whereas the HAZ width in material that thick is about 1/8" and the potential interference of the nozzle fillet toe on the long or girth seam is only at one point, your concerns are essentially pointless.

And I assume that the nozzle is a set on type where the full penetration weld thickness is the nozzle thickness. Again your concerns are pointless.