When procuring diesel storage tanks, the primary focus should be on material integrity and structural design. For underground tanks, double-walled fiberglass or jacketed steel is essential to prevent soil contamination. For above-ground tanks, ensure the use of high-grade carbon steel (ASTM A36 or equivalent) with a minimum thickness of 5mm to 8mm depending on capacity. Additionally, verify that the tank includes internal baffles to reduce fuel sloshing during transport (if mobile) and emergency pressure relief vents to prevent rupture under extreme heat.