I have a 500# propane tank that I keep filled. If SHTF what options do I have to access this fuel safely? Can it be transferred to 100# or 20# tanks? What appliances can be used directly on the 500#tank if any? Grills? Propane heaters? Which ones require regulators? It would be a shame for all that fuel sitting in my yard and not know how to access it safely. (of course, the more desperate one becomes the more risk they are willing to assume) Right now it supplies fuel to my furnace and water heater. Mind you...I only am interested in doing this in a long term SHTF scenario.