Under "Prequalified WPS Requirements", 3.29 (3) states "The minimum preheat shall be sufficient to remove moisture from the work, unless other means are used to keep moisture away from the weld puddle area."

5.1.2.1 states "Preheat temperatures shall be sufficient to remove moisture from the joints to be welded, as a minimum. Specific preheat and interpass temperatures are largely dependent on the material types and thickness to be welded. Both preheat and interpass temperatures shall be in accordance with the approved WPS or as otherwise specified or approved by the Engineer."

But, Table 4.1 "WPS Qualification Variables", 6.3 states "A decrease of more than 100°F [55°C] in the preheat temperature qualified. The minimum temperature for welding shall be specified in the WPS."

I'm having trouble locating what the "minimum temperature for welding" is. D1.6 seems to be less clear than D1.1 with regards to a minimum "temperature for welding", and according to 6.3 in Table 4.1, this is something that must be shown on the WPS.

Where can I find this information? We're welding 304 to 304 and 304 to 316L.