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Steam Drum - Separators Replacement

Steam Drum - Separators Replacement

Steam Drum - Separators Replacement


We need to replace existing separators from a steam drum with new separators. Can Separators be supports welded with shell ? Is it a violation or it will require R stamp ?

RE: Steam Drum - Separators Replacement

Any attachment welding performed on the pressure boundary material (shell) is under the NBIC (R-Stamp).

RE: Steam Drum - Separators Replacement

Thank you for your reply.
Can you please help me with the following as well ?

Our company does not contains R stamp, now this project is under manufacturing stage of separators that will be installed in May 2017. What will be the process for R stamp?
and what inspection & testing processes shall be during and after installation of separators

RE: Steam Drum - Separators Replacement

The process for obtaining an R-Certificate from the National Board of Boiler and Pressure Vessel Inspectors is outlined below


Typically for attachment (fillet) welds to a pressure boundary (drum shell surface), either Liquid Penetrant or wet fluorescent MT are selected to ensure the integrity of fillet welds.

RE: Steam Drum - Separators Replacement

Thank you sir for answering all

Can you please help me with the following as well

I have WPS for P.No 1 Group 1 SA 106 Gr. B, Will it be approved / applicable for SA 516 Gr 70 P. No. 1 Group 2?

RE: Steam Drum - Separators Replacement

You only need a P-No 1 to P-No 1 WPS for the above so yes it is acceptable.Group numbers only apply for impact qualification WPS, and since this is a BPV I component, no impact qualification is necessary.

RE: Steam Drum - Separators Replacement

Since this is a steam drum this will likely require field PWHT as well, which can be quite costly.

I suggest you look into finding a way to detach the separators an inch or two away from the ID of the drum, thereby making it a non-Code weld. If this isn't possible, see NBIC RD-1030 for PWHT alternatives.


RE: Steam Drum - Separators Replacement

Thank you for your replies @metengr & @christine74

Regarding PWHT, we are following ASME VIII Div 1 UCS-56 which states that PWHT is applicable for P1 material unless preheat of 200F is applied for 32mm to 38mm thick shell plates

RE: Steam Drum - Separators Replacement

If this is a boiler steam drum you should be using Section I. Also, you could use the National Board Inspection Code for repairs. In lieu of PWHT for the drum elevated preheat could be used. This is Welding Method 1 in the NBIC.

RE: Steam Drum - Separators Replacement

This is not a boiler steam drum that is why we are using Section VIII
Thank you for mentioning PWHT exemption code

There is another question regarding WPS
IS there any separate WPS required for socket welds, we have already butt weld wps

RE: Steam Drum - Separators Replacement


RE: Steam Drum - Separators Replacement

Is there any code which supports that butt weld covers socket welds

RE: Steam Drum - Separators Replacement

Section IX does. Has a lovely table and everything...

Nathan Brink

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