External Propane Tank?

[FlaBucki]

Does any one know whether there is a way to connect an external propane tank to the Interstate or directly to the Onan generator? I have a 250 gallon in ground tank at my home; I am thinking it might be handy in the event of an extended power outage (hurricane season in Florida) to be able to draw propane from my tank in order to use the Interstate for after storm shelter. I already have stub outs off the tank lines for my grill and mosquito trap.

[HowieE]

Any propane dealer will have what you need.

I use quick disconnects from my natural gas line in the house to connect to my generator in emergencies. It is just a mater of getting a regulator from the tank to supply the right pressure for what ever you want to power.

[Protagonist]

You will not be able to make a persistent connection from your home in-ground tank to your Interstate's permanently-installed tank to run your Interstate's installed generator. The connection for filling the Interstate's tank is meant to accept liquid propane, not gaseous, and the overflow valve has to be open as liquid propane enters the tank; you tell that the tank is full when liquid propane first starts to flow from the overflow valve.

However, you should be able to set up a propane fill station feeding off your home tank, allowing you to refill the Interstate's permanently-installed tank from your home in-ground tank. Whether you can legally refill your Interstate's tank is a matter for the state regulations that apply; commercial fillers must be licensed, but private fillers might not have to be.

You may be able to install a T in the line feeding the generator, allowing you to connect a separate line from your in-home tank directly to the generator, bypassing your Interstate's built-in tank. I'm not familiar enough with NFPA 58, the Propane Gas Code, which has been adopted by the RVIA for propane installations in RVs, to know whether you can have connections for a built-in tank and an external tank/cylinder on the same RV.

[Boxster1971]

The trailer folks hook up external tanks all the time. The fellow that sold me my first Airstream trailer used it on Kodak Island, Alaska all winter with a large external 100 lb tank. Don't know if it would be code compliant but you could connect right to the existing quick-disconnect with low pressure LP and supply the entire van with the internal propane tank turned off.

I think pulling liquid LP from your in-ground tank would be risky.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[Protagonist]

Originally Posted by Boxster1971

The trailer folks hook up external tanks all the time. The fellow that sold me my first Airstream trailer used it on Kodak Island, Alaska all winter with a large external 100 lb tank. Don't know if it would be code compliant but you could connect right to the existing quick-disconnect with low pressure LP and supply the entire van with the internal propane tank turned off.

The difference between the trailers and the Interstates is that the trailers are designed to hook up to DOT cylinders, and as long as you have a DOT-compliant connector on the big tank, the trailer's systems don't know the difference. Horizontal ASME propane tanks on the Interstates are somewhat different in that regard, since everything is hard-plumbed.

I honestly don't know if you could feed low-pressure propane into the Interstate's systems through the quick disconnect outlet that you would normally use to hook up a propane grill. That's a matter for an RVIA-certified master technician, which I'm not one.

I will keep following this thread, though, for the sake of curiosity.

[HowieE]

As long as you are hooking into the low pressure system it would not make a difference what style tanks are involved on the high pressure side.

You could never draw liquid from the underground tank. There is a regulator at the tank that reduces the pressure.

I used to draw propane off my trailer to increase the HP of my diesel truck. Used a quick disconnect between the TV and trailer and an electric control valve at both ends for safety reasons. When I pushed a switch in the truck both valve opened and raw propane was feed directly into the air cleaner and I was off to the races. Great for passing a slow poke.

[73shark]

Kind of a poor man's Nitrous system, huh.

[Skater]

I've seen external tanks hooked to motor homes for people who were wintering over in cold places. However, I haven't been close enough to one to see how it was set up (and who knows if it was to code). I'd suggest contacting a propane dealer - such as the one that fills your tank - to see if they can do it.

[slowmover]

A bit off topic, but be sure to understand how to service that generator. It doesn't take long to need to change oil, etc, as that may be daily.

A Generac backup power unit may be a much better choice (leaving aside questions of cost). One may still use the RV and this heavy use isn't as taxing given a large separate genset.

In the oilfield the gate guards using gensets have dedicated trailer 15-25Kw diesel fired units. They are not immune to problems, but are easy to service and are operating easily within design parameters.

Step back for largest picture. Being able to live in the RV is great. I think jt is the clinching argument for a homeowner to have one as adjunct to house, not just mobile living.

But reliance on such a small genset may not be the right approach. Not in packaging, duty cycle, etc.