Anyone used on board air to pressurize a water tank?

[tte30m3]

I have on board air in my tow vehicle. I will have a 18g water tank in the trailer. Rather than adding another component (pump), it seem like I could add a fitting and pressure regulator to pressurize the tank for my water pressure. I'm guessing I'd need less than 10 lbs of pressure.

Thanks!

 

[LuckyDan]

Actually, back in the day pressurized potable tanks were somewhat common on regular camp trailers. As a kid my relatives had a Kenskill trailer with a pressurized tank. The fill lid had a inner tube valve in the middle of it. Used to keep a bicycle pump in the storage bin to service it in the woods.

I think those tanks were steel though. I don't know if a modern poly molded tank would take much if any pressure beyond what the water itself exerts. Maybe? Maybe not?

Good luck however you do it.

 

[Robert Bills]

Vintage Airstreams also had air pressurized water cylinders fitted with Schrader valves. Early tanks were galvanized steel; later versions were aluminum. The trailer industry began using 12v demand pumps rather than air pressurized systems in the early 1960's.


Example of Airstream tank:

Air pressurized tank from Streamline trailer:

I think LuckyDan is correct that one cannot pressurize a poly tank with air - it would bulge and increase volume rather than build pressure, and most likely leak long before working pressure is reached.

I use a simple gravity feed system with the 13 gal. poly tank in my Bantam trailer (ignore the rust on the "radiator" fill tube - it was wirebrushed off and painted after the photo was taken).

If I ever find that I "need" running water I will plumb an inexpensive RV hand pump faucet into the system and call it a day.

 

[RagnarD]

At one point I was considering marking one out of a beer/Pepsi keg. Never got around to it though.

 

[twblanset]

I did this with two soda/Cornellius kegs in my drawer system. They are very light and are safe to pressurize to 150lbs. I use a pressure reducer and a little generic sink sprayer. If you are interested, reply here and i'll take pictures and do a small write up this weekend. I'm a homebrewer so I had the soda kegs lying around, but you can buy them used off of Craigslist without a problem.

 

[jeep670]

I did this with two soda/Cornellius kegs in my drawer system. They are very light and are safe to pressurize to 150lbs. I use a pressure reducer and a little generic sink sprayer. If you are interested, reply here and i'll take pictures and do a small write up this weekend. I'm a homebrewer so I had the soda kegs lying around, but you can buy them used off of Craigslist without a problem.

I'm interested. Thanks in advance!

 

[downhill]

Just be sure your compressor does not contaminate your water. Any oiled pump will have some oil vapor in the air it pumps.

 

[Nd4SpdSe]

I've seen this done in a Jeep rear bumper using his OBA. I'm sure it's pretty easy to find on YT

 

[Brettster]

I'm pressurizing a 10' piece of schedule 40 PVC pipe for my water tank. It holds exactly 15 gallons and runs at 25psi.
I have a small oil less air pump connected thru a pressure switch. Works like a charm.

 

[KTM-Todd]

IF 5 gal of water is enough a soda keg will work great, not cheap any more because of the home brewers buy them up fast. If you need more that five gallons just put in a pump. Any kind of water tank that can handle pressure is going to be expensive be it plastic or steel, stainless steel or aluminum. I got a very heavy 15 gal drum from work to make a week sprayer to use with my compressor. at 15 pounds the drum almost looked like a ball. And with a 20' 3/8' hose hardly no pressure. I cut the drum apart to fit it in the garbage and it had a wall thickness of 1/4" on the thin side to over 3/8". Good luck finding an RV water tank that thick. A good pump is what $75-$100?