Models ISO 40 Tanker (Heavy Fuel Oil Storage Tank) 9 81 2 ISO 40 Tanker (Compartments for fresh lube oil, service lube oil, service lube oil and process water) 13 53 1 ISO 20 Tanker (sludge compartment and diesel) 9 49 1 Biodiesel storage tank UL-142 6 51 1