Short answer is yes.. The adapter you have.. Question is there a small screw in plug in the side of it, Hex plug? If so all you need is the hose
There were, in days gone past, two products made by a company called Marshall Brass.. Now I know one of them has been picked up by another company since MB no longer makes them.
Extend-a-Flow was designed for TRAILERS with removable tanks. This was exactly what you describe.. It had a POL male fitting to go into one of the RV tanks, a POL Female (Took the hose that used to be hooked to the tank) and a "Quick Connector" (Looks like the top of a 1 pound bottle).
The Extend-a-Stay was the other product
Looked exactly like the Extend-a-Flow but with the addition of a nut on the side that was actually a screw in plug/inlet fitting, A special hose with a matching screw in part connects to a portable bottle
I know this one is now called "Stay-a-while" at stores like Camping world. So if you have that screw in plug.. You got the right adapter. all you need is the hose... If not, then you need the Stay-a-while.
I also found one called "Stay Longer"
Here is the Stay-a-while the fitting I talk about above is on the "Front" as photographed.. The Quick Connect is on the top.
http://propanegear.com/stay-a-while-tee/
