Do those V Band Flanges have an O ring gasket in them also?
I don't know if they will move when you have them coated. How hot does the oven need to get for ceramic coating? Will they fit in the oven all put together?
My brother-in-law is a metalurgist and has the second largest oven in Texas so oven size is not an issue. He is a Shop Foreman for the second largest heat treaters here.