Wasted propane on extension hose after shutting off

WrkrBee

Super Active Member
May 23, 2018
6,545
South Carolina
If you don't propane that was under pressure will lose the pressure in the lines and change from a gas to a liquid. Over the years you'll have a lot of liquid (not gas) propane in your lines that backs up and gets into the regulator and destroys the rubber in the regulator and blocks the flow of gas. I recently changed my regulator and found a whole bunch of liquid (not gas) propane that came pouring out when I disconnected the regulator to replace it.
Probably water in the propane lines. Regulator vents need to be turned down. If up, they collect water and during a freeze will damage the regulator. It will then feed the water into the lines. May be why you had to change the regulator.
 

HillHoward

Member
Nov 20, 2012
12
Propane is a distillation cut that contains other petroleum products. (Like "natural gas" isn't all methane.) There are "heavies" or "tars" in the propane. It's important to install your regulator correctly so that the drain is pointed in the correct direction (down). I had a RV shop install one on my PUC and they put it in upside down, so it fouled in short order. Bleeding out the lines after use is wise and also safer.
 

rabird

Howdy!
Mar 3, 2006
7,806
N. TX
the vent is on the atmosphere side, ie the none sealed side and allows the diaphragm to move and any condensation to leave. plasticizers in the high pressure hose leach out of the hose at high pressure along with any crap in the propane.

Mr heater has a special high pressure hose that doesn't need a filter when used.
"Currently, we make three hose models that do not require a filter: the F273704 which is made from a different chemical compound of rubber that does not have the oily substance that can get into the fuel flow, the F271802 that attaches to a low-pressure line, and the F271803 which is a regulated hose. Since the F271802 & F271803 only see low pressure, the oily substances are not squeezed from the hose material."

One hot summer I left the baby Q's cylinder valve open for a week in 110F high temps (12' hose). Next use, A slug of yellow oily substance made it to the regulator, I disconnected and used the high pressure propane (~200 psi @ 110F) to clear the hose. I likely did not do this when it was 110F so the pressure was much lower, something like 150 [email protected]

Just like the water hose, what is left in the hose is a non issue to me.
 
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CampingFamily1

Super Active Member
May 12, 2007
969
Minneapolis/St. Paul, MN
Propane is a distillation cut that contains other petroleum products. (Like "natural gas" isn't all methane.) There are "heavies" or "tars" in the propane. It's important to install your regulator correctly so that the drain is pointed in the correct direction (down). I had a RV shop install one on my PUC and they put it in upside down, so it fouled in short order. Bleeding out the lines after use is wise and also safer.

Thanks for the corrections and clarifications

This explanation above about heavies or tars makes the most sense.
My regulator was installed the correct direction.

What drained out when I changed the regulator was not water. It had a terrible smell to it. I wiped it up with a paper towel and that paper towel smelled so bad for days I had to remove it from my trunk where it was stinking up the whole trunk.

The LP and RV service store who has been in business for like 50 years and are experts in LP said to burn off all the propane in the brass camper lines or else this terrible smelling liquid (whatever it is technically) accumulates and reduces pressure in the lines and can ruin the regulator if it gets into the rubber diaphragm.

It does make sense that the regulator drain, would drain this liquid out the bottom hole, so maybe I got the information somewhat mixed up.

Thanks if anyone can add more clarity.
 

CampingFamily1

Super Active Member
May 12, 2007
969
Minneapolis/St. Paul, MN
So with all this new information what would you all say was the technical name for the stinky liquid that poured out of my gas line when I took the regulator off. It drained all over my hand and onto the garage floor. It had the viscosity of like water, it was brown, not clear, and smelled terrible. I had to wash my hand several times to get it clean. The paper towel used to soak it all up was brown and almost a full sheet was saturated.

My understanding from the LP and RV service specialists was that it was "propane", and that's as technical as they knew how to describe it.
 

CampingFamily1

Super Active Member
May 12, 2007
969
Minneapolis/St. Paul, MN
I never drain my lines, makes it too hard to start my fridge before hitting the road if I do....

That's a reason I never wanted to bleed off my lines.
I guessed it took longer to light the refrig on my next camping trip
Until I saw how much brown stinky liquid (technical term :) accumulates in the lines.
Sometimes we leave the refrig burning while we go for one last swim on the way out of the state park
In that case I'll need to bleed the lines using the refrigerator, which is still burning, rather than a stove burning until it runs out of propane gas.
But normally I prefer to use a stove to bleed the lines because it doesn't have it's own regulator, on top of the propane tank regulator, so a stove is much simpler.

Now that I'm bleading the lines by burning off the propane until it stops burning, I'm noticing it takes the same amount of time or less for the refrigerator to light on the next trip.
An now with clean gas lines and a new regulator everything seems to light faster and burn stronger in my camper.
 

Adam H

Active Member
Aug 22, 2015
549
California
When I was working at Ford, we saw a lot of LP vehicles come in with plugged fuel lines. This was exactly as described above and what was found was the fill stations they used had bad compressor seals causing compressor oil to get into the tanks... Unless you leave the lines open to the atmosphere, there shouldn't be a build up unless the tank was contaminated when it was filled. It has nothing to do with leaving pressure in the lines. I suspect the propane station either is guessing / blowing smoke or covering up their bad compressor contaminating bottles.
BTW, there is no cleaning of the tanks, if you have this issue get exchange tanks...
 

tfischer

A bad day camping beats a good day at the office
Whenever you disconnect your tank you're "draining the lines".

Here's my procedure for purging them. I don't even need to pop up: My furnace's thermostat is right inside the half door. So I turn on the tank, turn on the thermostat, and wait until I feel hot air coming out of the exhaust (which is near the door also so it's convenient). Then I turn it back off. This gets gas most of the way through the system. The fridge is across the aisle on the street side of the camper but it's much easier to light it after doing the furnace first.

Many people say "bleed the system with your stove first" but I'd have to pop-up to do that.
 

Matt D Wilder

Member
Feb 27, 2019
61
I learned this year that its really good to burn off propane in the lines before you pack up and drive home. If you don't propane that was under pressure will lose the pressure in the lines and change from a gas to a liquid. Over the years you'll have a lot of liquid (not gas) propane in your lines that backs up and gets into the regulator and destroys the rubber in the regulator and blocks the flow of gas. I recently changed my regulator and found a whole bunch of liquid (not gas) propane that came pouring out when I disconnected the regulator to replace it. My friends at the LP service store said that's why you want to burn off all the propane in the lines before driving home. So now I have a new practice. I made a video about my process to change the regulator but have not had time to edit it yet. This was one of the learnings from that process. I have much better gas pressure now that all that liquid is drained out of my lines any my appliances run the way they are supposed to.

It is impossible for propane to be liquid in the absence of pressure. 177psi minimum at 100 degrees. Your liquid is just gummed up condensation
 

rabird

Howdy!
Mar 3, 2006
7,806
N. TX
So with all this new information what would you all say was the technical name for the stinky liquid that poured out of my gas line when I took the regulator off. It drained all over my hand and onto the garage floor. It had the viscosity of like water, it was brown, not clear, and smelled terrible. I had to wash my hand several times to get it clean. The paper towel used to soak it all up was brown and almost a full sheet was saturated.

My understanding from the LP and RV service specialists was that it was "propane", and that's as technical as they knew how to describe it.

https://propane.com/wp-content/uploads/2020/01/FS_11297_Hose.pdf
https://propane.com/research-develo...p-gas-propane-hose-prior-to-entering-service/

there can all kinds of heavy hydrocarbons from various sources, the smell is likely mercaptan, the stuff they add to propane to make it smell.
 

CampingFamily1

Super Active Member
May 12, 2007
969
Minneapolis/St. Paul, MN
https://propane.com/wp-content/uploads/2020/01/FS_11297_Hose.pdf
https://propane.com/research-develo...p-gas-propane-hose-prior-to-entering-service/

there can all kinds of heavy hydrocarbons from various sources, the smell is likely mercaptan, the stuff they add to propane to make it smell.

Thanks for these links, but they appear to relate to a rubber hose.
I only have brass pipes/lines under my camper where the liquid accumulated over the years.

Still searching for a consensus of what the liquid was
 

CampingFamily1

Super Active Member
May 12, 2007
969
Minneapolis/St. Paul, MN
It looks like this subject is discussed in other RV forum threads as well with several ideas of what to call it

Here's another where forum user "IceChicken" says:

By leaving high pressure in the hose with the change in temperatures since you last used it may have caused the vapor in the line to change back into liquid form causing the oil.
Shutting the tank off and burning the gas left in the hose should solve the problem.

Sounds like there are differing things people have heard about what causes this oil/liquid.
 
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Sjm9911

Super Active Member
May 31, 2018
11,443
Nj
Never herd of oil in propane lines before. Ever. Water from not purging your tank, or water maybe getting into the system, but never oil. And i have freinds that heat there homes with propane, and we had propane heat in the lake house for 15 years.
 

rabird

Howdy!
Mar 3, 2006
7,806
N. TX
I only have brass pipes/lines under my camper where the liquid accumulated over the years.

Are you suggesting the 'brass pipe/lines' under your camper are high pressure?
There lots of sources of contamination and use of hoses/high pressure to get propane to your low pressure 'brass' lines.
The low pressure vapor under your camper (call it 0.5 psi) would take extreme cold to change to liquid.
 

Old_Geezer

Super Active Member
Sep 29, 2009
2,760
Southwest PA
And the issue is???????

I have been disconnecting all this stuff on pack up day and jamming it in storage without caring about any gas still in the lines for over 10 years. Still works fine next trip. Whats the issue again? And I was also told that using hoses that were not rated for propane was a disaster waiting to happen. On certain forums it was stated I would cause everything from forest fires to explosions and at best the hoses would dissolve into dust. That also never played out. Most are 200 psi goodyear compressed air hoses except for the short appliance extensions.

jBKKZCJl.jpg
 
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Eville Edna

Member
Mar 22, 2019
44
Vancouver, BC
I did the exact same modification this year and the first time I put the hose away in the camper i didn't think much of it, that is until I went to retrieve it and the smell it left in the cupboard inside was nasty. Propane smells nasty, especially from a rubber hose (15ft) in a contained area. So now I just turn the hose off at the tank and burn it off from the stove. The first time I did it is seemed to take forever to finish, I actually thought I hadn't turned the tank off properly, but no, it was definitely off. It took a good minute or so and I too was thinking about the waste, then I figured it only took about $40 CAD to fill it up and they take an age to empty so I calculated it's only about 4c of gas if that so it's worth that much not to have the smell or the risk of flammables in the camper.
 




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