Yeah, that’s the cause of some interesting pressure gauge behavior that initially confused me. The CO2 tank will read just under 900 PSI for ages, then drops like a rock. Due to some chemistry stuff about gasses that I long ago forgot, as long as there’s any liquid in the tank, the gas pressure in the tank will read as full. Once the last little bit of liquid CO2 has been depleted, even 900 PSI of gaseous CO2 will not last long in a carbonating situation.
Perhaps just as well you went for the Amazon hose.
I recently tried to order one of the cheap ones from one of the eBay sellers, and a couple days later got an odd apologetic message that they only had one left and it was damaged, and she’d be canceling and refunding my money. I was puzzled, as the listing still showed up, and I didn’t reply. Sure enough, a refund came through a couple days later. But now, any time I try to bid on a similar item on eBay, it says I’m blocked from purchasing. Obviously, one of the Chinese import operations has a bunch of different eBay accounts listing these hoses, supposedly in different US locations—but why they have no product and have blocked me from all of them I can’t quite figure out.
At any rate, after a reinstallation (and a week of buying seltzer at the supermarket) my old hose no longer seemed to leak gas, so the need for a new one abated.
Sounds like it is good that the tank be full of liquid, because liquid CO2 is denser than the gas. The vapor pressure at room temperature will be 5.7 MPa or more or less, depending on the temperature; whatever it is will not change if you extract some.
As does target. Also there are more than one service where you just sign up to send in your empties and have full ones returned.
Now, more than a month on (it feels like much longer), I finally have a satisfactorily working setup. I got a full used 5-lb tank at the nearby gas supplier and ordered this hose that comes with a pressure gauge and relief valve.
It all seemed to work fine at first, but after a few days the Sodastream machine started leaking, so that a faint stream of gas was constantly coming out of the nozzle. At first I thought I might have damaged something in the inner workings of the Sodastream, but after watching some videos on how to take it apart, I finally realized that the fault was in the valve in the adapter that screws into the SS machine.
It my research, I learned that it’s not necessary to open the top valve on the cylinder all the way, and that I may have actually caused the damage to the adapter valve by doing so. Since then I only open the valve l a little bit, and slowly
So I bought another hose, longer and made of stainless steel, with a metal adapter, but no gauge or bleed valve. Although the increased length was more convenient in my setup, the new valve wouldn’t open when connected to my machine. Returned.
I then bought just a valve, to use with my original hose. No joy, same as the last one. Returned.
Finally, I bought another hose that seemed to have the same valve as my original, but without the gauge and bleed valve, so it was cheaper. I transferred the valve to the original hose (because I find the gauge and bleed valve to be convenient), and finally everything worked just the way I wanted it to.
So it was a bit of a slog, and took some figuring out, but I got there in the end. Thanks for all the suggestions and advice.