So, I don't know much about plumbing, but I know that many plumbing parts are specialized with a certain type of fluid in mind in their design. I'm wondering if this is true of check valves, and if so what kind of valve I should use for a line where water will run one way and air will be exerting pressure against the flow. I'm building a box for dispensing CO2 by evaporating dry ice. There will be an adjustable valve for the output and an air line input to force gas out. I plan to put a check valve and a shutoff valve on the air input so that I can seal up the box when not in use.
I'd also like to add something to raise the heat inside the box when I want a higher CO2 concentration. I'm not certain about what kind of heating element would be advised, and I prefer mechanical tools over electric anyways, so my idea was to have an optional water input. Like the air input, it would have a shutoff valve as well as a check valve to prevent backflow. But do I need to use a special type of check valve if I want water to flow through it but expect the stuff that tries to flow the other way will be air?
My gut tells me that no, a valve built for a dense, hard-to-compress fluid like water should have no problem resisting the physical stresses of air. But I've been wrong about this kind of thing before. Also, since there will be low temperatures, what type of material will resist cracking/freezing up? Is there a certain check valve design that's better suited to this application?