Installing an underground propane tank comes with a completely different set of rules and specifications that have to be met in order to ensure that it’s both legal and safe. The underground propane tanks are designed specifically to be installed underground and yet still allow access to all the necessary features.
Even though the actual tank fittings, valves and connections are generally same amongst propane tanks, the actual placement is obviously different depending on whether it’s above or below ground. A surface tank will usually have the relief and withdrawal valves positioned outside the dome and normally on opposite ends of the tank. With an underground propane tank, all of the fittings and connections are positioned centrally so they can be protected by both the dome walls and cover.
And finally for those not sure, yes it is illegal to bury a propane tank designated for use above ground.
I have included this video so anyone thinking about going for an underground tank can see what is involved. Enjoy!