This came up as an ancillary issue on a genset thread. To avoid hijacking that thread, I am starting a new thread here.

Bill, feel free to remove my posts and references thereto from that thread.

[edited by Bill N.Y.]
To follow the original line of thinking I'll link both threads. The thread and the pictures that Bill H is talking about can be found here.
[/end edit]

quote:

Originally posted by MWrench:

There is oil in LP gas and it will accumulate in the vapor converter/regulator.

quote:

Originally posted by bill h:
I wonder if that oil also accumulates in the propane tank. I have oil in the lines to my barbecue and the Portable Buddy heater. I am concerned with the oil fouling the burner in our portable Buddy heater. At present I use a filter in the line.

quote:

Originally posted by MWrench:
I was told that it will accumulate in the tank by a propane dealer here but have not had a chance to confirm, if there is enough to get into the lines and foul the vapor regulator, probably would be enough to gradually accumulate in the tank. I would also assume that oil would be more of a problem in liquid propane (used for the generator) then in the vapor side that is used for the stove, furnace, and water heater. I didn't see any evidence of oil in the furnace line when I change the furnace last year.

I saw no oil in the copper line when I disconnected my furnace, either. However, I see oil in the flex lines to our BBQ and portable heater. I often get a little oil on my fingers as I disconnect either end of the hose. Standard AN fittings. It is possible that the propane is leaching some oil out of the rubber hose. I have had correspendance with an engineer at Mr Heater about that, but was reluctant to accept that theory. However, this discussion is causing me to reconsider the rubber hose issue. Perhaps different materials will have different results. I wonder if the UL approval for propane hoses allows different rubber compounds.

The hose theory is good news, as it will rule out the possibility removing and draining the tank of any accumulated oil.

Ed, what are those blue hoses in the picture in the gen thread? Never saw blue propane hose before.

HI Bill:

That is Parker "push-lok" 801-8, MSHA IC-40/22, hose and is the same as was on there when the Beam regulator was mounted to the gen set right next to the venturi jets. Has a working pressure of 250 PSI, looks like it is black rubber inside the braid (not steel braid). The local supplier said it should be fine for propane vapor and also could use it for coolant. It is not used for the liquid propane input to the Beam regulator.

HTH

My hose man says propane hose must have perforations in the outer jacket to prevent a blister forming.

I would guess that if the inner liner were more permeable than the outer jacket (or developed a fault), a blister could result. If a blister failed, it could let a more concentrated mixture of propane int a compartment than seepage would.

He never heard of the oil leaching out theory, but is he not exactly an engineer. In fact, lots of over the counter information is of doubtful provenance. But, then, chemistry was one of my weaker subjects.

Looking at Parker http://www.parker.com/hpd/literature/pdf/4281_b1.pdf

They say that "Push Lok is not recommended for any fuel." I wonder if that means propane, and whether gas or liquid.

I see that the 801 is synthetic rubber, while the 836 is PKR elastomer. Other than higher temp, it is listed as suitable for the same stuff. Elastomer is, (dare I say it?) a rather elastic term. It could just be another way of saying rubber or it could be a thermoplastic. I wonder if it would be less subject to the leaching out of oil. I would also feel more comfortable with a material that would perhaps be less permeable for the hose that goes inside the coach to the portable heater.

The Parker propane hose page, http://www.parker.com/ead/cm2.asp?cmid=3726 shows only nitrile hoses with perforated jackets. They go on about the tiny molecules of propane getting through standrd rubber or PVC hoses. They also caution against using their hose indoors, so I guess I will just keep buying propane bottles. Or just rely on my propane detector.

I see that McMaster sells Buna-N propane hose, which is another way of saying nitrile. I always thought Buna-N was one of the tribal chiefs in the first King Solomon's Mines movie. Weatherhead http://hydraulics.eaton.com/products//pdfs/fc/W-HYOV-MC...parts_36-49_hose.pdf also lists nitrile as their propane hose material.

All good information Bill, I am sure we all rely on information from supposed "experts".

In this application I am not worried, there is NO propane vapor or liquid in the hose when the generator is off. That is controlled by the solenoid on the input port of the Beam regulator. There is no propane vapor pressure in the hose while running, the venturi jets located in the airflow just before the throttle will create a slight vacuum and that will open the regulator to supply only enough propane vapor for a proper mixture which is completely used by the engine.

I really have more of an issue with the liquid delivery hose, I am in the process of making up a shield for it in the area where it goes up the firewall. If I were in an unfortunate situation where I hit something hard enough to deform the front of the coach, that delivery hose could be damaged, yes there is an auto shut off valve but it is at the tank and there is a lot of liquid propane in a hose that is 30 fett long!

Further, I have had some question about the use of copper for the delivery of propane from the black iron distribution pipe to the various inside appliances. With all the vibration a coach sees going down the road, I can very well see where fractures at the flare could occur. The way the copper runs on my coach are it looks like some kid did it! Some of the bends are kinked and others have been resting on a frame rail being sawed! (those 2 where replaced shortly after I got the Barth) I am going to replace all copper runs this winter but haven't found a suitable replacement for the copper tubing yet.

And YES, I have 2 propane detectors in the coach along with an aircraft style CO detector.

Enough rambling for a Holiday and hope everyone had an enjoyable summer!!! I did and put well over 10K miles on our Barth!!

There are certain allowances (7 lbs./1000 cubic feet)for stuff in natural gas of which propane(byproduct of natural gas) is drawn off at the processing plant. They try to extract the bad stuff like sulfuric acid (eats pipelines), oil, natural gasoline, butane, and water. There could easily be some residual oil in propane.

Add to which, the product added to give naturally odorless propane its characteristic odor is called, "onion oil."

quote:

Originally posted by olroy, The Old Man and The Barth

Nice literary reference, that. I still remember the artwork that accompanied Life Magazine's first publication of it. I wonder if I can find it.