Planned mods to propane system

danmcdonald99 · 08-28-2014, 11:44 AM

I am planning two modifications to my propane system and want to see if anybody has any thoughts on them.

This all started with a trip to a propane specialty shop in Denver. The guys there seemed extremely knowledgeable and professional. They suggested these two modifications. I am planning on following their advice and having them make these mods.

First is to disconnect the external propane outlet that I asked SMB to add to my build. I don’t remember where I got the idea to add that but it could only have been somewhere on this forum. The propane guy did not like the look of it. SMB’s workmanship is fine but the propane guy felt that the whole idea of an unregulated flow of propane through a hose attached to the underside of the van is unsafe and illegal. Since I have not found it useful to me anyway I am very happy to simply have him disconnect it.

Part of the reason that I have not used it is because even on my first fill of propane I have been introduced to the adverse effects of the oil that is added to propane. I hooked my camp stove up to the outlet a few times. The oil in the onboard propane soon fouled the stove’s regulator. I know now that I should have used a filter between the system and the stove.

That leads me to the second planned modification. They have suggested putting in a trap mechanism that will minimize the amount of oil that flows through the system and will allow the excess to be drained periodically. I found on the internet an account of somebody else who has had that done. Here’s his description:

“I have had the "oil" like substance plug our camper lines more than once and only once in our other 5'ers. I made the simple change on the systems as was suggested (by a propane specialty shop). A low spot reservoir and drain! As I had also noticed the "oil" always seemed to gather at the lowest point, that was the logical place to revise. Our gas hoses went up from there to the top of the propane compartment as they went into the camper. I replaced the brass elbow with a same thread size brass "TEE". Reattached the camper hose and put a short extension fitting and a cap on the new opening that pointed down. Depending on the extension used, a cap or plug could be used to seal the gas system. This now catches the oil in the lowest spot reservoir and only requires me to turn the gas valves off and remove the cap a let the accumulated oil drain. 2-3 minutes at most. Put the cap back on and turn on the gas again. Problem solved! I drain each year rather than waiting until a problem occurs. Be sure to use Teflon tape or pipe compound on the threads for no leaks.”

Does anybody have any thoughts on any of this?

rallypanam · 08-28-2014, 12:17 PM

Quote:

Originally Posted by danmcdonald99

First is to disconnect the external propane outlet that I asked SMB to add to my build. I don’t remember where I got the idea to add that but it could only have been somewhere on this forum. The propane guy did not like the look of it. SMB’s workmanship is fine but the propane guy felt that the whole idea of an unregulated flow of propane through a hose attached to the underside of the van is unsafe and illegal.

I'm going to add this to my van. I don't know how SMB did yours, but mine will be controlled by at least the main tank valve, and I will likely add another valve to this line, which would then prevent the flow of propane unless I turn both valves on, so I'm not too worried about safety.

Quote:

Originally Posted by danmcdonald99

Part of the reason that I have not used it is because even on my first fill of propane I have been introduced to the adverse effects of the oil that is added to propane. I hooked my camp stove up to the outlet a few times. The oil in the onboard propane soon fouled the stove’s regulator. I know now that I should have used a filter between the system and the stove.

So the propane they put in your system is different than the propane they put in regular BBQ cans? I'm a little confused here, and don't understand why your stove would get fouled. But then I'm new to on-board propane, maybe it's the same propane but it works differently in the lines on a permanently mounted setup?

danmcdonald99 · 08-28-2014, 01:52 PM

That's a good idea about having a control valve right at the tank before the propane goes into the hose. That would seem to address the safety issue. Mine does not have that.

I wondered the same thing about the green canisters vs big refillable tanks. As you can tell, I'm not a propane expert. All I can tell you for sure is that the propane that goes into the refillable tanks definitely has a small amount of oil in it.

rallypanam · 08-28-2014, 03:51 PM

Well, nobody seemed to chime in, so I went off in search.. seems the 'oil' is added to the propane to make it smell like, well, um, what propane smells like.

But in general, you shouldn't have any significant amount in your system, unless the tank has been overfilled repeatedly (I found this theory a lot):
http://rvtravel.com/publish/rvdoctor379.shtml

It also seems like if you have a lot of oil, it's probably coming from somewhere other than the propane, like a bad supplier with a contaminated tank, or the tank wasn't cleaned properly when manufactured, or whatever.

All that said, doesn't seem like it could hurt to put the drip drain in...

danmcdonald99 · 08-28-2014, 04:48 PM

All of that about the reason for the oil and the about repeated overfilling matches what I have read too.

The repeated overfilling doesn't apply in my case because my system is brand new and I saw the oil residue while the original batch of propane was in the van from its original purchase last winter.

But here's another little snippet that I just found on the internet that might explain why I was getting oil coming out to the camp stove. (Everything you read on the internet is true, right?)

"You do not want to leave propane pressurized in the rubber hose. It will cause the rubber to release an oil that will gunk up you propane devices. When you are done using the propane shut the tank off first and let the device burn off the propane that is in the hose. Once the flame goes out it is safe to turn the device control knob to the off position."

I was definitely not doing that. I was turning off the stove, putting the cap back on the hose and only later turning the propane off at the tank. That would have left propane in that hose.

rallypanam · 08-28-2014, 05:29 PM

Quote:

Originally Posted by danmcdonald99

"You do not want to leave propane pressurized in the rubber hose. It will cause the rubber to release an oil that will gunk up you propane devices. When you are done using the propane shut the tank off first and let the device burn off the propane that is in the hose. Once the flame goes out it is safe to turn the device control knob to the off position."

Interesting. Now i need to poke around in my van.. Does SMB use rubber hose to go to stove and furnace?

86Scotty · 08-28-2014, 07:24 PM

No, flexible copper.

rallypanam · 08-28-2014, 07:36 PM

Quote:

Originally Posted by 86Scotty

No, flexible copper.

Thanks. That takes my todo list down to 741.

**daveb** · 08-28-2014, 10:51 PM

I had SMB put an outside propane inlet to feed my flush mounted stove so all I had to do was to hook up the 1 gal tank I usually haul for my outside BBQ to power the inside stove. It was kind of a PITA to hook up so I figured why not purchase the same quick disconnect SMB sells as their "Extenda Flow" propane extension uses. Well my propane guy was dead set against it for similar reasons. To rely on an O-ring wasn't a good idea in his opinion dealing with high pressure. I figured I could just add a regulator to the tank to lower the pressure but the stove has it's own regulator and he said you can't have a regular feed a regulator. So if that is the case how does the extenda flow work safely? I was told the quick disconnect was rated for high pressure though. Because of that I figure it's legal.
Anyway I just had SMB add a small on board elongated tank. The disconnect is still there and I never use it so maybe I should get rid of it

witoke · 08-29-2014, 03:25 AM

" To rely on an O-ring wasn't a good idea in his opinion dealing with high pressure."

Find another propane place. O rings are the engineering standard for sealing almost any substance, liquid or gas and at pressures that would blow holes in the side of your van. Just learn how to tighten it appropriately, they are damaged by over tightening.