The Flame King Refill Kit adapter is much safer to use with the Flame King 1# cylinders as it has a trigger/deadman shutoff valve, so you aren't fumbling with the turn valve on the 20# cylinder once the 1# reaches the safe ~90% full and the vent starts spitting liquid - just let go, it stops. And it gets the tank orientation right with the 20# cylinder stand the 1# cylinder is upright. NOTE: Always do your filling outside and well away from any flame source like the Water Heater.
With the old Mr Heater straight fill adapter with the 20# cylinder inverted the 1# tank is horizontal and the vent will spit early. Or you put the 20# horizontal and can't use it all, it will stop filling at roughly halfway depending on which way the Overfill Valve inside the 20# tank swings. (This calls for a cutaway tank picture or diagram of how that Overfill Valve works. This is not a use they planned for when designing that Overfill Valve.)
The Overfill Valve inside newer 20# cylinders will kick in at maybe 20% left when inverted, as the level drops it to what would be the "Full" position when vertical - Plan to not get every drop out of the 20# tank. Use it with a bulk hose directly to an appliance (BBQ) if you need to use up every drop before exchanging or bulk filling the 20# tank.
Date published: 2018-02-10