How to re-assemble bronze dual ball washing machine after soldering?

[Kris Kersch]

I took the valve apart and soldered. Found liquid flux had a better flow, seal, and adherence than paste flux. Anyone with advise on putting it back together so it doesn't leak. How should the screws be tightened? Do you silicone the O-rings? They look awfully thin. Had a Power Out in the middle of this post so here goes just in case!