Pressurized water tank

[larrie]

For some the person who owned my SMB before me pulled the fresh water tank and pump out from under the sink. They left the pump switch, wiring, sink drain, and city water connection. I want to replace the on board fresh water but am not sure that I want to put in a pumped system.

Has anyone put in a pressurized water system?

My thought is to have a fresh water tank that can hold around 10 gallons at 65 to 90psi. At that pressure the water should flow out of the faucet just like at home.

As the pressure in the tank decreases it could be brought back up with either a hand pump or on board air.

Thoughts?


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I am here: http://maps.google.com/maps?ll=45.605993,-123.945605
- Larrie
89 Ford RB

[Skywagon]

"Thoughts?"

How about a non-pressurized tank and a Shur-flo pump? You get steady water pressure and no need to re-pressurize the tank all the time.
Plus you don't need a pressure tank...

Bill

[Ford_6L_E350]

You are looking at substantial metal tank. Maybe a 15-20 gallon tank to hold 10 gallons and enough air volume to keep it pressurized.

Tank can't be bare steel, it would rust. Aluminum might work, maybe 3/16" thick to hold the pressure. It should be a round tank, like an air tank on a compressor, to best resist the pressure and deformation.

Look at a 20 gallon air compressor tank for approximate size. Or maybe two 10 gallon tanks, one for water, one for air. Where would you locate it? Who will fabricate it for you? Would you have it pressure tested?

A rectangular plastic tank and pump look like a much simpler, smaller solution to the problem.

Mike

[scatter]

Originally Posted by Skywagon

How about a non-pressurized tank and a Shur-flo pump? You get steady water pressure and no need to re-pressurize the tank all the time.
Plus you don't need a pressure tank...

Bill

X2. You're making things a bit more complicated then you need to. But if that's what you want, and if the noise of the Sure-flo running each time you want water bothers you, check out Badger's site. He put in a pressurized system.

[jage]

I don't think it's a bad idea, I do think you shouldn't be looking at a house/well type system- you don't need to deliver 8 GPM after all.

I've got a pressure washer that runs off of compressed air. It stinks as a pressure washer, but as a pressurized water source or outdoor shower it's great. The pressure comes from the OBA source- which is not pressurized for long term use but simply drives the water- meaning your air compressor will run instead of the sure-flo pump, but in terms of simplifying the system and dual purposing your OBA, I don't see why it wouldn't work.

[Silver350]

Cement trucks have pressurized water for adding water to the cement or washing off the equipment. If you have an on board compressor you can just put a regulator on the water tank and you're done.

I read of a couple that overlanded for 20 years in a VW Bus. They had a gravity feed system with the tank at the rear inside of the raised roof. no moving parts there, didn't do much for COG, however.

[joey2cool]

I'm with Jage on this one. If you only carry 10 gallons of water in a tank, it's gone in four minutes at 2.5 gpm (which is what the SMB installed faucet feeds at using Shurflow pump head pressure). Even with a water restrictor, you're not going to extend water use much. The entire system should not exceed 120 psi or it will require steel piping vs. plastic. If you're into using a hand pump faucet, that would work too.

[larrie]

This is all great information. Thanks. I am thinking of doing this Myth Buster style. There is some 3" PVC pipe in the back yard that will be used as to make a proof of concept small scale test setup. If that works then I will up scale it in PVC and do some additional testing.

Still working out location. So far have come up with three; under the body with protection plate, back under he sink, or on the floor under the stove.

Am trying to stay away of an electric water pump. Am already sharing circuits because my distribution panel only has four. The one for the pump is being used for the Igloo cooler.


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I am here: http://maps.google.com/maps?ll=44.590346,-123.264525
- Larrie
89 Ford RB

[Ford_6L_E350]

A word of caution here. PVC pipe and pressurized air are not a good combination. Over time the pressure will cause the PVC to crack and fail. Pressurized air will rapidly expand and the PVC will literally explode, throwing shards everywhere. It doesn't happen to every piece of PVC, and it doesn't happen immediately. But, it can happen and with nasty results. That is why is against codes everywhere to run compressed air in PVC pipe. A test with a piece of PVC will only prove that piece won't explode at the test pressure and time. It could blowup an hour or a year later, or maybe never. I've seen one PVC/compressed air (100 psi) explosion, and it wasn't pretty. It was the reason my garage has compessed air run in copper pipe.

Water in PVC is not an issue, because if the pipe fails, it simply leaks because the water will not expand like air will.

If you really want to do this, do it at a reduced pressure, under 20psi, not at the 65-90 psi you earlier proposed.

Mike

[Zeta]

I had an Adventurewagen Syncro that had one. Giant PIA. Not only did you have to worry about water leaks, but you also had to worry about air leaks. The AW had on on-board compressor to refill the m***********g thing.

Almost cost me my will to live.

Z