Putting the CO2 tank in there is fine, however, it will make your tank gauge in accurate since it is a liquid and cooler liquids take up less volume. That being said, as soon as it comes out of the tank and into the regulator, the pressure will be accurate since it is in a gas form. (someone correct me if im mistaken)
You're mistaken. Well actually that's not true, your statement that cooler liquids take up less volume is correct (hence the shrinkage of your batch from boil to pitching, and hydrometer correction).
But that isn't why the pressure gauge will read lower when the tank is in the fridge. The reason is that the vapor pressure of CO2 is lower at lower temperatures, and that is essentially what the primary gauge is measuring (and what makes it useless for anything except determining when your tank is almost completely empty; at that point all the liquid will have evaporated to gas, so the gauge will act like a normal gas gauge).
Edit: To add, you are correct on the last point you made. The pressure in the tank is way higher than in the hose, and the CO2 will be gas when it leaves the secondary regulator, so the pressure will be accurate.
Enter your email address to join: