Preheat reuirements for fillet welds 1

[wagnermj]

I have a scope of work to seal weld two plugs (3/4" dia tapered S/S 304) to an existing tube (SA-179 x .083") and tube sheet (SA516-70 x 1-1/8") using GTAW process and ER309L filler material. I plan to use a two-pass process to accomplish this work. My question is: Do I need to consider preheat/ heat maintenance above 50° F (Minimum on WPS) due to the thickness of the tubesheet.

 

[metengr]

Yes, for this tubesheet thickness. I would recommend a 150 deg F minimum preheat.