Thermocouple welds require ASME/R-Stamp?

[rmillercwi]

I have recently been involved in the attachment of temporary thermocouples to boiler tubes that has been in service for some time. Have done it many times. Process and equipment (Zap gun) identical to what is used when attaching thermocouple to completed welds to monitor PWHT temperature.

The customer is asking about an R-stamp and all the relevant paperwork that would go with it. I dont believe its required but dont really have an answer to give as to why I believe this. It is a weld process being performed on a pressure part and I guess technicly would require a qualified welder and procedure. Or is an R-stamp and the associated paperwork nessesary or is there an "out" in the NBIC code somewhere?

Thank you in advance

 

[SnTMan]

rmillercwi, sorry I am not able to answer your question, but this looks to me like following logic off the cliff.

Regards,

Mike

 

[metengr]

You don't need to have an ASME qualified welding procedure specification for attaching TC's using a capacitance discharge method. ASME Section VIII does accept the capacitance discharge method to attach temporary TC's during fabrication. They consider it as being similar to resistance welding in accepting it's use.
Interpretation: VIII-80-50
Subject: Section VIII - Divisions 1 and 2, Attachment of Studs or Thermocouples to a Vessel
Date Issued: June 5, 1980
File Number: BC-79-332

Since you don't need to have or to qualify an ASME welding procedure for the capacitance discharge technique, this is outside of the scope of the NBIC (R-Certificate).

 

[rmillercwi]

Thanks Metenger. I tried to locate the interpretation you detailed and could not find it. Perhaps I am out of touch with older interpretations? I searched both divisions 1 and 2 diligently and could not find it.

 

[moseley]

rmiller,
you should still contact your AI and let him know what the customer is wanting. There decision is probably coming from their AI? Like it has been said above the process that you use to attach these TC's isn't considered a welding procedure (although some engineers believe that it is)and if the boiler tubes are less than 5" OD then this would still be considered a "routine repair" which doesn't usually doesn't considered stamping the vessel. This all depends on the customer's AI and your AI's interpretation.