Walrus- Those boxed look like NEMA-3R (raintight) to me.
Would this stuff be required to be explosion-proof? How big must the tanks be- and does this apply only where you are pumping LPG?
I'm not being silly- I note that LPG vendors are x-proof, but no households are- and some of them have some BIG tanks!
Incidentally, NEC defines the zone as 20 feet from the tank.
