water in gas line ?

[rtt108]

I was camping this weekend, set up the pop-up (93 Coleman Destiny), turned on the gas, went to light the stove ... nothing.   That's odd, I'm sure the tank was full.

The tank was full, all connections were fine.  What could possibly be wrong?  I disconnected the fittings on the gas line, the regulator was fine and I was getting gas out of that.  Took the fitting off the stove end of the line, set the hose down, and about a pint of water came out of the fuel line !

What could cause a gas line to fill with water?  The stove end was stored in the camper and was not exposed to rain.  The tank end is always connected to the tank.

The only think I can think of is that the pressure regulator has a small air vent on it.  Perhaps it was pointed upward and rain water has been getting in since last summer, when I last used the camper.

I plan to replace the regulator just for good measure.

[austinado16]

I just had an '84 Coleman that was like this exactly.  Same exact scenario as you for diagnostics, and then I blew through the gas line with my mouth and out came a bunch of water.

This camper had been sitting outside for a long time, and I didn't think about water getting into that vent.  But everything worked fine (stove and Duo-Therm Furnace) after I blew through the line.

You wouldn't think that that vent would allow outside air/rain to mix with the propane, otherwise, you'd have a propane leak.  That air vent is most likely so the rubber diaphram inside (that regulates propane pressure) can have only atmospheric pressure on it, as you change elevations during driving and camping.

Definately a weird one.  Could there be water in the propane tank?  Like from either condensation, or from the big tank that filled your tank up? Or both?

[rtt108]

I doubt there is water in the tank.  No, I'm sure it came from the regulator.
Forgot to mention, I had the regulator disconnected and cycled the rubber diaphram in it with a screwdriver (being very careful not to puncture anything), and the air vent spurted black water.  So the regulator had water in it too.

Since I don't know if the vent on the regulator is supposed to allow outside air into the system, I don't know if the regulator is faulty, or if it just was mounted wrong (vent up).

For good measure, when I got home I hooked up ye-olde air compressor and blew out the gas line on the camper until no mist came out the other end.  I wanted that line good an dry.

[austinado16]

Yes, I remember reading in the Starcraft manual that they wanted their 2 stage regulator, which had the vent facing sideways, mounted so that the vent faced down.  This put the regulator on it's side.

When I put that Coleman back together, I put one of those vinyl regulator covers on the regulator, so that should solve the problem.....if it's indeed water getting into the regulator.

[coach]

As mentioned, water won't enter the system through the diaphragm.

The diaphragm moves (spring travel) as pressure is regulated and the 'back' side needs to be open to air, otherwise it would be in vacuum and pressure as it moves. Every time I turn the propane on to my grill, a puff of air comes out the vent hole. Water in the vent will cause the diaphragm/spring to not preform properly.

I'm always amazed at the 'oil in propane lines' and 'water in propane lines' tales. I've yet to have this problem. No wonder Mr. Heater has a in-line filter fir use with 20# containers.

[rtt108]

So I'm a little confused ... should I be replacing the regulator ?

[austinado16]

It wouldn't hurt, because if it had water in that vent, the spring and other metal goodies on the back side of the diaphram are probably all rusty or corroded.  Of course they/it won't fail in camp driveway.

I'm guessing that just like with gasoline tanks, the big propane tanks get water condensation in them, and then that is passed on to the customer and you wind up with water in your tank(s).

I installed a furnace about 2 years ago and when it wouldn't light, I started taking apart the gas valve on the furnace itself.  I found a bunch of rust and corrosion inside the valve.  Cleaned it, and it worked fine.  But I was wondering, "how did the inside of a propane gas valve get rusty?"  I guess now I know.

[wavery]

The water probably came from your propane tank.

This is one reason that I always get my tanks filled and never let them sit around empty. An empty propane tank will get quite a bit of condensation inside, over time and some exchange tanks may sit around for months.

As long as there is at least 1 gal of gas inside the tank, it is less likely that condensation will get inside. The pressure inside the tank will keep condensation from forming. As pressure decreases, condensation increases.

[rtt108]

I always keep the tank full.  When my gas grill tank is empty I fill it and swap it onto the camper.  So the tank on the camper is always full.  This one had been filled last summer.  I always use the same place to fill, and have never had a water issue in over 15 years.  I also never use exchange tanks.  

It also seems like a LOT of water to suddenly appear in the line.

I guess it's kind of a moot point.  I'll swap the regulator and keep an eye on it.

[coach]

be sure the vent is oriented down. They make RV 2 stage regulators that vent different direction depending on how the regulator is installed.

Getting rid of the left hand thread POL and replacing with a pigtail that has an ACME QCC-1 connector to the tank makes changing tanks without a wrench possible! Secure the regulator.