Originally Posted by ddrueckh
In my experience, the gauge does not show tank fill level, just that it has pressure or no pressure. Once the tank empties, the gauge will quickly change from green to red. I don't see a problem with mixing a 100lb and 30lb tank. The regulator should operate the same. Good luck.
The green/red indicator on the regulator only indicates pressure coming from whichever tank the dial is aimed at; it does not indicate fuel level in any way (except empty).
So regardless if you have a 5# cylinder or a 100# cylinder, when the fuel runs out, the "barber pole" turns from green to red and the regulator opens up the other side and begins allowing fuel from the "non-service" side. It's telling you "hey, your main service tank is empty, so I'm running on your 'backup' tank. You need to fill the 'service' tank".
The fuel will not stop flowing unless both tanks connected to the regulator are empty, assuming your equipment is working properly.
This happened to me last weekend. But I'm running the standard twin tanks. So when the regulator turned red, I rotated the dial on the regulator and closed the valve on the empty tank. So now what was my 'backup' tank is now my main service tank, and the empty tank is awaiting a refill in my garage. When I get it refilled and reinstalled, it will become my "backup" tank. And I'll start the whole process over again!
2014 Jay Flight 28 BHBE
2015 RAM 2500 6.4L HEMI, Tradesman 4x4, 3.73
Blue Ox SwayPro (BXW 1503)
Upgraded from an REI internal frame backpack and a Eureka 1/2 dome tent!