B31.3 Can you tack welds without Filler?

[stanweld99]

Per B31.3, 328.5.1 (C) Tack welds at the root of the joint shall be made with filler metal equivalent to that used in the root pass.

Does that mean you have to use filler material for tack welds or you can weld autogenously, but you will need to use the same filler as the root if you tack weld with filler.

Just want to confirm if we can tack welds autogenously.

 

[metengr]

Yes, tack welds can be autogenous.

 

[GenB]

the whole root can be autogenousmif you follow the Code