[Hernan Rizza]

gpsvn, if you are requiring carbide tungsten is because you have a metal-metal ball seat in your ESDV. Probably you have carbide tungsten in the ball and in the seat, and if you use carbide tungsten only in the seat and bare 316ss in the ball you are going to have the galling there. So, I think that 316 is ok for seat and ball but if you are going to use a metal-metal seat you have to use carbide tungsten in both sides.