Oil in the propane tank

[Magumba]

We've been using 30 lb propane tanks for many years now. One tank is a year old the other is three years old and they are hooked together then hooked to the extend a stay.

Recently the heater stopped working and thinking the tanks were empty, they were not, I unhooked the external tank and tried the heater on the internal tank. When I unscrewed the POL fitting from the tank I noticed oil on the treads.

We took the motor home to a local shop for some other work and had them check the propane system. They found oil in the propane lines and also replaced the regulator for us.

I have heard that there is a small amount of oil mixed in with the propane to prevent corrosion but we got too much in our last tank fill. So my question is. What do I do with the tanks I have? I'm concerned about using them and clogging my system again. Is there a way to flush the tanks?

Thanks for your help.

[Gary RVRoamer]

Yes, tanks can be purged and cleaned but it isn't cheap. A propane service shop (not a mere refill station) can do it for you, but depending on the area the labor cost may be near as much as a new tank.

I think I would try them as is and hope for the best. The oil mostly stays in the bottom of the tank, so even if it is there it may not cause a problem.

[Magumba]

Gary,
I was surprised to see on oil on threads of the POL fitting. I'll look into having the tanks cleaned.
Thank you for your help.

[Just For Fun]

Originally Posted by Gary RVRoamer

Yes, tanks can be purged and cleaned but it isn't cheap. A propane service shop (not a mere refill station) can do it for you, but depending on the area the labor cost may be near as much as a new tank.

I think I would try them as is and hope for the best. The oil mostly stays in the bottom of the tank, so even if it is there it may not cause a problem.

One minor suggestion from a total non-tech, if the oil is in the bottom of our tank (hopefully this isn't a stupid statement) make sure your tanks are level - never tipped over trying to get the last little bit of LP out.

[falconman]

I believe you can purchase an inexpensive inline filter for such a problem. Mr. Buddy (?) heaters recommend one for some of their heaters when used on smaller tanks.

[Magumba]

The tanks have always been right side up when being used. I use two hands to carry a full tank from the Jeep to the camper but still they were pretty much right side up. I've never turned the tanks over.

I'm thinking I got some bad gas from Tractor Supply.
Thank you for replying.

[menoble]

Word of caution, the residue in the bottom of an LP tank contains a concentration of Mercaptan (?) and will unleash a stink like no other that won't wash off if it gets on you.