12-02-2014, 10:31 AM
Tom 58propane
Va. Tom58 Can a 120lb tank be attached to the motor homes filler valve as backup????
12-02-2014, 12:28 PM
Steve VWI have a valve and a tee on my propane supply line (LOW pressure side!)
If I want to attach a line to an external device (i.e. grill) I can attach a hose and directly feed the device.
I have also used the tee to attach a separate cylinder. (This cylinder MUST have its own regulator) If I shut off the coach tank then I can use the extra tank and not deplete the coach tank.
I would be leery of any connections to the high pressure side (approx 150 psi) The low pressure side is about 11 inches of water (i.e. 1/2 psi!)
Ideally the tee will be between the coach regulator and the sniffer shutoff valve so the the sniffer would still stop the flow when needed.
From left to right: coach shutoff valve, two stage regulator, tee with valve and dust cap, sniffer shutoff valve, (wire attached, behind red valve handle) line out to coach (black flex line, hard to see, far right)
Looks like the road salt got to the paint. Need to clean and repaint, again...

12-02-2014, 05:54 PM
RustyShort answer, no. The fill fitting at a supplier is special, and is available only to licensed dealers. That said, the external tank would be at the same pressure as the installed tank; no significant flow would occur.
However, a bypass could be installed to allow the external tank to feed the system instead of the installed tank. I suggest using a licensed tech for that job.
12-02-2014, 10:09 PM
bill hI put in an extra long hose connecting the tank to the regulator. When we want to use a larger tank (for longer use), or a smaller portable tank (for portable refilling), I just move the hose from the coach tank to the aux tank.
The small tank gets dragged to town for a cheap and handy Costco refill and the big one gets filled from the propane truck (if I call on the right day of the week).