Propane filter to remove oil

[charles tuit]

My LPG generator is being repaired due to excess oil in the liquid propane line.

After the repairs are made I want to install a propane inline filter to remove excess oil. I'm thinking of a Nash Filter.

Does anyone have experience using a propane inline filter to remove oil in the line?

[halfwright]

I have one from Wal-Mart on a Big Buddy heater. Works great.

[PSOUZA]

Originally Posted by charles tuit

My LPG generator is being repaired due to excess oil in the liquid propane line.

After the repairs are made I want to install a propane inline filter to remove excess oil. I'm thinking of a Nash Filter.

Propane is a solvent. The oil is disolved in the propane. Just like you can't filter disolved oil from gasoline, neither can you "filter" oil from liquid propane.

What you can, and should do, is trap the oil after it falls out of solution at the regulator. This assumes your generator is using propane gas and is not liquid fed.

The LP regulator removes the oil from the liquid propane when it reduces the pressure to 11" WC.

The oil contamination becomes a problem because there is no provision to remove the accumulated oil after extraction by the reguator.

The cure is to install a resevoir at the lowest point in the low pressure line just after the regulator. Periodical draining of the resevoir is required to remove the acumulated oil. A popular term for this device is drip leg or drop pipe.

If your regulators frequently are damaged by the oil, change the regulator brand. Most will pass oil safely if the oil is not alowed to accumulate.

Phil

[charles tuit]

Thanks to the 2 members that responded. I guess 15 years of oil accumulation finally did the regulator in.

[Ray,IN]

Originally Posted by PSOUZA

Propane is a solvent. The oil is disolved in the propane. Just like you can't filter disolved oil from gasoline, neither can you "filter" oil from liquid propane.

What you can, and should do, is trap the oil after it falls out of solution at the regulator. This assumes your generator is using propane gas and is not liquid fed.

The LP regulator removes the oil from the liquid propane when it reduces the pressure to 11" WC.

The oil contamination becomes a problem because there is no provision to remove the accumulated oil after extraction by the reguator.

The cure is to install a resevoir at the lowest point in the low pressure line just after the regulator. Periodical draining of the resevoir is required to remove the acumulated oil. A popular term for this device is drip leg or drop pipe.

If your regulators frequently are damaged by the oil, change the regulator brand. Most will pass oil safely if the oil is not alowed to accumulate.

Phil

I don't think I've ever seen a permanent LP appliance without a drip-leg, it's in all installation instructions.

[PSOUZA]

Originally Posted by Ray,IN

I don't think I've ever seen a permanent LP appliance without a drip-leg, it's in all installation instructions.

And yet oil contamination in RVs remains a mystery to most who are afflicted with it.

I have had my nose into a fair number of Recreation Vehicles and have yet to see a drip-leg, in the proper location, from the factory.

It seems to be good for some businesses, though.

Phil

[WDW]

I don't believe we have one - or at least I've never found it. And i "though" I've been all over our rig, under and taking every access panel off to snoop.

[Bigd9]

If it is a Onan propane generator, it is a liquid propane that leaves the tank and gets converted to gas right before the cylinders. Onan has a rebuild kit for the "regulator" which is rather simple to install. The most expensive part of the process is getting the generator out of the coach. I did not find any drip leg.

[charles tuit]

Thanks to all. I looked for a drip-leg and didn't find one.

Buddy heaters sell what is described as a "oil filter". I searched propane oil filters and a company named Nash make various filters to remove oil from propane lines.

I was wondering if any members have installed a "oil filter".

Thanks again to all who responded.

[Bigd9]

Charlie you haven't indicated which generator your coach has. On the Onan Marquis propane generator I was familiar with, it has a fuel filter.

[charles tuit]

Sorry as I should have specified the generator. It is a Onan, HGJAB, LP, 6500, Gold.

It does have a oil drain on the generator itself. I must confess at age 74 and 240 plus I haven't done regular draining as much as I did in my younger years. You must open the unit up, crawl under and drain it. I'm looking for the lazy man's solution but after getting the bill for the service I now have incentive to drain it.

Thanks again to all.

[PSOUZA]

Originally Posted by Bigd9

If it is a Onan propane generator, it is a liquid propane that leaves the tank and gets converted to gas right before the cylinders. Onan has a rebuild kit for the "regulator" which is rather simple to install. The most expensive part of the process is getting the generator out of the coach. I did not find any drip leg.

The attachment describes the purpose of the filter as removing solid particles, particularly ferrous materials. It also describes the propane gas generation well, (fuel vaporizer) and seems to be a scaled down version of what modern fork lift equipment uses.

The fork lift users have monumental repair expenses caused by oil contamination as well as excessive down time caused by sludge in the vapor generator. If there were an effective filter to remove the oil, they would use it. There is none.

This link can provide some interesting reading on propane contamination.

http://www.rasoenterprises.com/propa...pane-residuals

Phil

[charles tuit]

Thanks to all for the input.