Question: I am planning to install a Natural Gas stove or fireplace in my home. Could you burn Propane in an emergency, without changing the orifice? If this is possible, what else do I need to do to make it work? Regulator? Answer: You do need to change at least the orifice for such a switch. Some appliances are unable to switch - others need two orifices changed (the pilot and valve orifices). Some units, like the ones from Travis Industries (http://hearth.com/travis) come with both orifices standard. The regulator needed for LP is usually installed on the tank - not the appliance...although some LP-only appliances have a second regulator on the LP burner.