Just a quickie [perhaps?]: I have rigged up three different gas bottles to my one regulator, so that I can choose whichever at a tap turn. All is fine and it is a good way to pressure test the regulator before putting expensive gas into the HP side, but that the ball valves right next to the regulator High side tends to leak a little. By leak, I mean ~ 0.05 scc/day/atm. So if there is 10 atm in the line to the regulator and the regulator has ~nothing in it, there is a ~0.5scc per day leakage into it.
I'm not so bothered about the leak rate itself, but it only has about [I estimate] 10 cc in the high side, so if I only have, say, 2 atm left in it and 10 in the line then after 4 days it will be 10% diluted with whichever gas was last in the line.
I can
1) add one or two more ball valves of the same time, such that I can vent high pressure into the space between the valves and it will leak out in both directions, mitigating dilution, or
2) I can buy a different valve, but should I try another ball type, or a needle valve, or other?
3) I could try adding a touch of thick silicone grease to the surface of the balls in the valves - i think it would actually be a good approach for this kind of leak rate, but would this help or hinder the ball's work?
4) I could just drop the multi-line approach and have one gas per regulator, of course!! This will necessitate some gas loss each time I swap the lines at the chamber end.