Remote Impound design for LPG installation

[swtmoon]

Hi there,

Does any one can help me to design remote impoundment for LPG installations?

Currently I should to design the remote impundment for 7 LGP bullets above ground.
Each size is 3.9 m Dia x 34.2 m L about 390m3 of LPG.
I've investigated API 2510 & 2510A but still can't figure out it's shape, depth or details.

If anyone has more specific examples please give me a hint.

Regards,

swtmoon