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Up Topic Welding Industry / ASME Codes / ASME B31.3 - MPI/LPT Requirement on GIrth/Butt Welds
- - By Nalla (***) Date 03-08-2010 14:24
Dear Friends

Base Material - CS & SS - Process Piping - Dia range from 2" to 6". Weld Porcess - GTAW(Root) SMAW (the rest ).
Based on what I've understood above code does not call for MPI/LPT on Butt/Girth Welds. I've done RT as as required in Project approved NDT Plan. Can some one guide to the code section which call for MPI/LPT? I need your guidance urgently. Thanks
Parent - - By Shane Feder (****) Date 03-09-2010 00:26
Nalla,
It is usually a requirment stipulated in the project specifications, not the code.
What service class are you fabricating to ?
If it is Severe Cyclic you will require MT / PT on specific joints but if it is Normal Fluid Service or Category D you will not.
Regards,
Shane
Parent - - By Nalla (***) Date 03-09-2010 07:33
Shane

Yes,it is Normal Fluid Service or Category D.

ISO drawing calls for 20%RT + 5%MT
Thanks
Parent - - By Shane Feder (****) Date 03-09-2010 07:42
Nalla,
Pretty standard if a little high for NFS / Cat D.
20% RT on your groove welds and 5% MT on sockolets/weldolets/ slip on flanges etc. Generally your 5% MT will be on items that you cannot RT.
Regards,
Shane
Parent - - By jon20013 (*****) Date 03-11-2010 12:12
There are no code requirements for MT of Normal Fluid Service or Cat. D welds.  MT only comes into play for severe cyclic and in that case for socket type welds that are not RT'd.  That said, the drawing in your case rules and your acceptance criteria should be: 344.3 Magnetic Particle Examination Examination of castings is covered in para. 302.3.3.
Magnetic particle examination of welds and of components other than castings shall be performed in accordance with BPV Code, Section V, Article 7.  Note too that acceptance criteria can also be made more restrictive by the fabricator or purchaser.
Parent - - By js55 (*****) Date 03-11-2010 13:41
Where you been hidin jon?
Parent - - By jon20013 (*****) Date 03-12-2010 06:06
I've just been back to work for a week, now working 28 days and off 28 days.  When I'm home in New Zealand I'm usually too busy enjoying life to come in! :)
Parent - By js55 (*****) Date 03-12-2010 14:13
I understand. You don't see me hittin this thing on weekends much.
Up Topic Welding Industry / ASME Codes / ASME B31.3 - MPI/LPT Requirement on GIrth/Butt Welds

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