Using Compressed Air to Blow Out Water Lines

bluesprinter · 10-05-2011, 03:10 PM

I apologize if this has been answered in another post but I looked and did not find anything.

I bought a compressor that is designed to inflate tires, sports balls, etc. Gauge goes up to something like 150 lbs/sq inch. Two issues.

1. Is this enough "power"("strength"?) to blow the water out of the water lines, and water pump?

2. Where is the best place to force in the compressed air? At the shore connection? What sort of adapter is used? (The compressor comes with a nozzle that fits tire valve stems and an adaptor that connects to the nozzle that is used to fill sports balls)

I get the impression I'm not getting the right picture here.

Thanks in advance.

woodbee · 10-05-2011, 03:54 PM

I think the compressor you have is low volume. What you need is volume, like out of a compressor tank. High pressure is not needed.

Woody

**BroncoHauler** · 10-05-2011, 06:45 PM

I might also be a a little concerned that your air might have a small, small amount of oil blow-by from the compressor. Not sure it's enough to matter, but then again, any amount may be too much. I have nothing to back up this hypothesis.

A CO2 tank could work.

Herb

**WVvan** · 10-05-2011, 07:29 PM

Another thing to think about is that you could easily rupture a RV water line. They aren't rated to withstand the PSI an air compressor can put out.

jage · 10-05-2011, 07:31 PM

"Blow out plug"

Mine is anodized aluminum, don't know where my brother bought it.

http://www.amazon.com/Camco-36143-Brass ... B002XL2IEA
http://www.fleetfarm.com/catalog/produc ... t%20search

bluesprinter · 10-05-2011, 07:51 PM

Learning a lot. Thanks, all. Have no idea how to figure out how much volume the pump will generate. I suppose given enough time it will crank out enough air . . . surely the lines and water pump don't hold more air volume than a tire???

oldbonesclimber · 10-05-2011, 08:00 PM

The Pex tubing is Bomber if it is installed correctly. It will hold 1000 PSI. In training it ony broke at 1220 psi and the tubing split, the fittings did not come off. I wouldn't worry about the pressure. Other components are the weak point but if the system is open I doubt if you have to worry.

Paul

jage · 10-05-2011, 09:15 PM

Quote:

Originally Posted by bluesprinter

I suppose given enough time it will crank out enough air . . . surely the lines and water pump don't hold more air volume than a tire???

The problem is it will gurgle in the lines and not blow completely out. You can probably seat a bead with that compressor if you're patient, but for the lines it would be better to get a tank, fill that to high pressure and then open it slightly to let a volume of low pressure air through. The problem is I run my compressor while walking around and opening and closing each drain, faucet, the shower which one small tank wouldn't be enough for.

bluesprinter · 10-05-2011, 09:46 PM

Quote:

Originally Posted by jage

Quote:

Originally Posted by bluesprinter

I suppose given enough time it will crank out enough air . . . surely the lines and water pump don't hold more air volume than a tire???

The problem is it will gurgle in the lines and not blow completely out. You can probably seat a bead with that compressor if you're patient, but for the lines it would be better to get a tank, fill that to high pressure and then open it slightly to let a volume of low pressure air through. The problem is I run my compressor while walking around and opening and closing each drain, faucet, the shower which one small tank wouldn't be enough for.

My goal is to get enough of the water out so that I don't risk a broken pump or water line when I take the SMB out for a spin during the winter, perhaps parking it for a few hours in below freezing temperatures. Most of the time it would be in the heated garage. The pump and lines are inside, so the interior would be at 70ish when parked, and then the temperature would drop down and eventually reach the exterior temperature. So I'm hoping I don't need to get every last drop out.

And then there's the vodka approach.

I suppose I can then mix up a "blend" of vodka and water, put some in the fresh water tank, and then pump it to the sink and other faucets.

Eventually, when I retire, I will head south and west for the winter.

jage · 10-05-2011, 10:49 PM

Quote:

Originally Posted by bluesprinter

The pump and lines are inside,

Are you sure? My lines, hot and cold, went up the driver wall diagonally, over the rear doors and down the passenger wall.

Incidentally, I also found two new, never opened line drains so far under the water heater I couldn't have turned them if I knew they were there.