Propane Fill Tank Conduit

[Moosifer]

I have done a minimal amount of explosionproof stuff.

I need to run a 120ft 3/4" conduit to a disconnect on building from a hardware store propane fill tank (#10 thhn - 20a 120v circuit).
I am not sure I have this all correct per code.
Seems like all fittings within the 1st 10ft need to be explosionproof.

Will this work:

Pump system explosionproof box female to 3/4 rigid (do I need an explosionproof male/female fitting here?)
-3/4 rigid to explosionproof capped elbow
-capped elbow to 3/4 rigid to 3/4 seal within 18" (do I need explosionproof male/female or can I put the rigid right in the capped elbow & seal?)
- then go underground 2ft and 90 out of the C1D1 area (can I use female/female explosionproof couplers and a 3/4 rigid 90 here to get 10ft out and then transition to normal rigid couplers for 110ft under ground in a trench and 90 up to a seal below the disconnect on the side of the building?)

Thank you for your help. I'd rather not screw this up.

 

[petersonra]

Doesn't the classified area end at the dirt? So I am thinking you need a seal before going underground.

 

[Moosifer]

I have one before the ground but I thought it still extended 10ft since propane is heavier than air.

 

[rbalex]

First question: Is the design compliant with Section 500.4? That should define your boundaries.