"GENERAL Storage tanks in refineries are used to store crude oil@ intermidiete and refined products@ gas@chemicals@ and water.Importent factors@ such as the volatility of the stored mateial and the desired storage pressure@ result in tanks being built in different types and sizes and of various construction materials. In this chapter only atmospheric and low-pressure storage tanks have been consider. The construction and inspection of high-pressure tanks designed to operate at pressures of more than 15 pounds per square inch gage are more closely related to that for pressure vessels; hence such tanks are considered in Chapter VI@ Unfired Pressure Vessels."""