Aha! Possible Propane Pipe Condensation

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ZuniJayne

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Greetings, all.....

I just learned that condensation in iron propane pipes can wreak havoc with your propane appliances.

I think that was part of my fridge problems (along with the bad thermocouple) and it was also the problem with my hot water heater.

Once I discovered this possiblity, I opened the T from the iron pipe to the copper pipe to the hwh. A black, oily liquid dribbled out.  After I let it drain a bit, I hooked it all back up and the hwh worked great!

I think this iron pipe should be blown out occasionally with compressed air.

Hennyway, you might want to check this out if you have problems with your appliances.  I don't have a manometer, so this was the poor woman's way.  ;)
 

Pat

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ZuniJayne:  Hmm.  I've gotten a black oily liquid out of the extension hose that goes from the Y connector in my propane system to the auxiliary propane tank that I use.  I haven't noticed it near the connection to the Y, but I have by the tank.  Just means I haven't noticed it.  Stinks, too.  I wonder if this iron pipe T exists at all the other propane appliances and has to be opened and cleaned.

--pat
 

Gary RV_Wizard

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I'm not sure this oily substance has anything to do with condensation, though oil and water do form a gooey semi-liquid.  But there isn't supposed to be any oil in your propane tank either.  However it got there, it will definitely block the flow of LPG to appliances and needs to be cleaned out.
 

Pat

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Gary:  How?  Is there a way to clean the whole propane system?  Maybe there's detergent propane, like Shell or somebody said they put in gasoline.

--pat
 

Gary RV_Wizard

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Because propane is light, the oil sits in the bottom of the tank. I'm not sure how it gets up into the lines - maybe when the propane level in the tank gets low, or as a result of sloshing while underway?  And I know of no way to get it out of the lines other than opening them letting it run out or blowing it out.  As for the tank itself, the only solution I have heard of is to open the tank (removing the fill valve) and physically dumping or sucking it out.  There is no additive to get it out because the oil cannot easily be vaporized like the propane.

Most people who have had an oil sludge problem seem to get by with draining the lines. I don't know how frequently the lines get re-polluted by oil from the tank. I guess you clean the lines and pray. If he problem returns fairly soon, the next step is a tank cleaning, probally expensive.  With portable (DOT) tanks, it might be just as cheap to replace them. With the fixed tanks in a motorhome, you are stuck with a cleaning bill.
 

Pat

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Gary:  I think it's my portable tank that had the oil, but I'll watch a few things.  One time I got the last of the LP in the big tank at the supplier.  I wonder if I took on some oil from his tank.  I wonder if the oil in the portable tank is what is causing my furnace to burn yellow.  I'll hook it up again and see if it's ok now.  I can always give away the tank and buy a new one, I guess.  And a new hose.  That portable tank is a lifesaver in winter, so I don't have to move the RV to get a refill. 

On this subject, the RV park where I winter has a truck that comes around with large LP tanks.  Like 100 gallons or something.  Would it work in a motorhome Y connection like my 7 gallon tank does? 

--pat
 

BernieD

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Pat

Our previous coach had a propane fueled generator. When we were at a rally in Greeley, CO, altitude over 6,000', temps over 100 and possibly a bad batch of propane, the generator failed. Onan diagnosed an oil coated fuel regulator and replaced it, solving the problem. It looks like 2 out of 3 of your symptoms match :D
 

Gary RV_Wizard

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On this subject, the RV park where I winter has a truck that comes around with large LP tanks.  Like 100 gallons or something.  Would it work in a motorhome Y connection like my 7 gallon tank does?

Those big tanks still have a standard POL fitting. That's the same "old style" LPG connector that portable tanks used to have and is still present as the internal left-hand screw threads in the new style OPD valve.  The LPG hose you have will fit those big tanks.
 

Pat

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OK, so I'll see if I can find the propane regulators.  I take it there's one on the onboard tank and one on each propane appliance?  I do know the furnace is burning cleanly little blue dots now that I'm fueling it from the onboard tank, so I think everything in the onboard system is clean.  I just need to clean the auxiliary hose and aux tank.  I may just replace the aux hose altogether.  Are there regulators for the auxiliary tanks?

--pat
 

ZuniJayne

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Pat,

I just got back on line - sorry to delay replying to you, but it looks like you are getting your questions answered well anyway.(That is one thing I love about this forum.)

Usually there is just one regulator per propane tank. 

"On this subject, the RV park where I winter has a truck that comes around with large LP tanks.  Like 100 gallons or something.  W"ould it work in a motorhome Y connection like my 7 gallon tank does? "

Yes, I did that two winters ago.  However, be aware that some RV parks require connections for those 100 gallon tanks to be solid pipe and not just a hose like I did out in the boonies.  They may also require you to put the tank a specified minimum feet away from your rig
 

Pat

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Jayne:  When you say one regulator per tank, I have two tanks.  There is a 19-gallon tank onboard my motorhome.  I had a Y connector installed in the propane line, and I attach a hose to that and out to a 7-gallon auxiliary tank.  Does that mean two tanks and two regulators?  I don't have a regulator on the auxiliary tank.

--pat
 

quapaw

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Having used propane for motor fuel plus the more common useage of heating etc, I have never encountered any amounts of oil or paraffin buildup in a tank or regulator.  I have had convertors IE: a unit that converts the LP liquid to gas via heated water from the cooling system on the engines, that would show some evidence of oil or wax (pariffin).  It definately would cause problems in a regulator and/or orfices.  I suspect your tank may have been filled from someone's tanker that had not been purged to remove any buildup.  It is possible that the supplier's tank had been contaminated by their delivery supplier.  As to regulators, trailers normally have one regulator for two 20# or larger tanks.  Both tanks entering the same regulator.  A motorhome with one tank would have a regulator and if one adds a tee fitting to allow the addition of a protable tank, it must be plumbed into the line BEFORE or in front of the regulator.  LP gas is not to be taken lightly.  All gas burning applicances should be checked on a regular basis to make certain they are in good operating condition.  Best if a professional does the work as they have the testing equipment and knowledge to do so.  A service call is cheaper than a funeral. 
 

ZuniJayne

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Pat,

QuaPaw had a bette/clearer answer about the number of regulators. My own travel trailer has one regulator for both standard 10 gallon tanks.  When I added the 100 gallon tank, I used the same regulator.

I have discovered in my travels that there are all sorts of qualities of propane, dealers, etc.  Most folks have no problems with their propane; others have a lot.

QuaPaw is also right about respecting the volatility of propane.
 
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