Wow, you guys need to get out more often! (teasing)

If you look at the tank clearance diagrams in the appendix of NFPA 58, you'll see three diagrams: DOT cylinders, ASME above ground tanks and ASME buried tanks. There is a 10 foot clearance from this tank bonnet to the building or property lines where buildings could be built up to 2000 gallons. There is a chart for clearance per tank size.

3.2.9.1
a) containers installed in areas with no vehicle trafiic shall be installed at least 6" below grade
b)In areas where vehicle traffis is expected, a noninterchangeable underground container shall be installed at least 18" below grade or the container shall be protected from damage from vehicles. Protection shall be provided for the fitting housing (bonnet), housing cover, tank connections, and piping against vehicle damage.
It also addresses construction or excavation near the tank.

Seriously, buried tanks are all the rage around Philly. I guess it is a regional thing. BTW, size being the same, a buried tank performs better than an above ground cylinder as far as vaporization rate goes.

The copper high pressure line coming up out of the ground should be coated, sleeved or protected. It should run into an approved gas cock then a second stage regulator then enter the building again with a sleeve. Rarely done.

HTH

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disgusted with some people on this forum. Out of here!