That's a great point about the heating, pressurizing the cooker. I'll have to install a pressure gauge on the pressure cooker. I think they may come with a pressure relief valve.
Yes, my compressor is an oil less Viair. I have a 2 gallon air tank that it charges. I should be able to drain the pressure cooker several times on one tank charge.
Great tip on the Balston filter. Looks like I pick one up on Ebay, reasonably.
Since you guys have me thinking about clean air, I've come up with a possible alternative. I have a 3 lb. CO2 bottle, with a regulator. I used to use it before I had electric OBA and I could easily justify it as redundant air on my trailer. Off the top of my head, I should be able to pump a bunch of showers out of one 3 lb. CO2 bottle. I tried to do the actual calculations, but I got hung up on the Boyles Law stuff. This much I determined. At sea level, 1 lb. of CO2 decompresses to about 65 gallons of air. So a 3 lb. tank will hold about 195 gallons of air at 0 PSI. What I don't know is how many gallons it is at 15 PSI (which is my pressure cooker operating pressure). Is it as simple as dividing by a factor of 15? If so, I'd get 13 gallons of air at 15 PSI out of a 3 lb. CO2 fill. The pressure cooker is two gallons, so I'd get 7+ water runs out of one 3 lb. air tank. Any engineers reading this?
I'll probably do both, the coalescing filter and the CO2, with the electric OBA as backup.
I would think that it would make its own pressure as it is heated. I would heat it first then add pressure if needed.
As for the oil in the potable water I would suggest a good coalescing filter like a Balston and an oil less compressor if you plan to drink it, but if it is for bathing and washing I would not be concerned the greatest time for oil carryover will be while the pump is running and for a little bit after it has stopped, so some planning my be part of keeping the majority of oil contaminants out if a coalescing filter is not used.
