I have two 20# tanks (21 years old) for the patio here at home and two 30# tanks (23 years old) in my '97 5er. The home is on propane so my bulk dealer refills every thing. All tanks were refitted with the new valves and recert at no cost to me.
I had a 20# tank from my 1972 9' 6" truck camper that was blown away in a '75 tornado. Never found a second tank. I used the tank till 2015 when propane dealer said too much rust showing around one spot on the side caused in the tornado.
My neighbor refills from their 500 gallon LP tank for their 40' LEQ trailer.
