I can't believe that when I search "external propane tank" there are NO returns on this forum. It makes sense that it wouldn't be a popular topic for trailers
since pretty much all trailer propane tanks are "external," but there are no threads containing information regarding hooking up an external (larger or portable) tank to a motorhome with a permanently mounted propane tank?!
Well, let's fix that.
This thread is in regard to allowing you to hook up external portable appliances as well as an external tank. Why would you want to do this? Lots of reasons, but the biggest one would be that you need propane, and you can't move your rig! The second biggest reason would surely be if you were semi-permanently parked somewhere and wanted to hook up to a much larger tank than what is able to be mounted to the frame.
So... there are kits marketed by names such as Stay-a-while, Stay-longer, 4 port tee adapter, etc. Basically they are an adapter that goes in between the tank and the pressure regulator, and they have available 1"-20 Male Throwaway Cylinder Thread, 1/4" Inverted Flare (female) ports.
The available ports were driving me crazy, because while the throw-away cylinder thread makes sense (you can hook up a portable grill or whatever uses those little 1lb. propane bottles with an extension hose made for throw-away style cylinders), the 1/4" port doesn't seem like a "temporary" solution to anything. I'm not sure if you're supposed to leave a pigtail always connected to this port (dragging along as you drive down the road?), or if you are suppose to thread and unthread the 1/4" flare connection every time you want to use an external tank (like a 20# cylinder), but it seems like it would make a lot more sense to be able to use a hose with an Acme Nut type connector on both ends (like what hooks up to a typical 20# BBQ grill tank), so you can easily connect and disconnect an external tank.
I know you can plumb anything you want by simply using the appropriate brass fittings, but for the life of me I can't figure out why this set up is the standard
for this type of kit.
If you could use a quick connect for the 1/4" inverted flare port, that would make more sense, but all the "quick connect" hose and connector options on Amazon are low pressure only, so they won't work with this type of set up. When using the Stay-a-while type adapter, the adapter goes before
the pressure regulator, so all the connections you are making are high pressure.
There are certainly high-pressure quick connects available from propane specialty sources, but the lack of availability gives me pause.
I feel like the aforementioned Acme Nut to Acme Nut hose would be a great option, so I'm tempted to make the 1/4" inverted flare port my permanent (to the motorhome) connection, and leave the acme threads (like what a typical tank has) open for the external tank connection. Is there a reason not
to do this? This would also allow one to hook up a regular grill to the motorhome, because there would be an available port that functions like a regular 20# BBQ tank.