Tank and Vessel Info (2014)API Tanks & API 12F tanks are typically used out in the oilfields , and store gasoline, petroleum, and other types of oil. These bulk storage tanks are fabricated using only the strictest guidelines. These specifications allow for the oil products to be stored safely and in the most cost effective manner. Watkins knows what this means to your bottom line. We have decades of experience fabricating API Tanks & API 12F stainless steel tanks, and we take pride in the fact that we are one of the top stainless steel tank manufacturers in the industry. All tanks are built onsite and are pressure tested prior to shipment.