Ha, you beat me to it I see.It's not safe and it's not legal to bury a propane tank designed for above ground use.
They use the same valves and fittings but they're located differently. The also use a different coating and need a tower/riser to protect everything (in addition to the cathodic protection).
You'd also have to be very careful about the location of the tank because they can float. You'd need to anchor them or bury the feet in cement before you cover the tank. You should also cover the tank with some sort of non-abrasive material (like sand) before backfilling because rocks and other debris can compromise the protective coating and could render the cathodic protective bag useless against corrosion.
Last edited: