chuck,
Yes, API-650 tanks are commonly used to store diesel fuel and other petrochemicals. API-650 contains rules for tank design based on the specific gravity of the contents and matreials selection based on the geographic location of the tank.
Some of the special considerations you must consider for storing diesel fuel are contained in NFPA-30. Be sure to evaluate tank placement with regardard to occupied buildings and property lines.
Alternatively, you may want to the use of the UL standards (UL-58 and UL-142)in the tank specification. Many diesel storage tanks in the USA use these as design standards
My thoughts only...
MJC