Chapter 6 - Steel and fiberglass construction for below ground storage tanks

Abstract

The principal use for underground storage tanks for the past fifty years has been petroleum, petroleum products, and chemical storage. Underground storage tanks are widely used for a number of reasons. Fire hazards are greatly reduced by surrounding tanks with an inert soft. By placing tanks underground, more effective use of aboveground spaces can be made. Belowground storage also eliminates the aesthetic concerns associated with aboveground storage tanks. Traditionally tanks had been constructed of steel. In the 1960's, fiberglass-reinforced plastic tanks were introduced. This chapter compares steel and fiberglass tanks for underground storage. The expansion of the petroleum and chemical industries over the past half-century has seen the advancement of underground storage tank technologies. A majority of below grade tanks now being installed by the major oil companies are fiberglass. The advantage of fiberglass is its resistance to corrosion. The advantage of steel is its strength and broad chemical compatibility. Steel tank manufacturers have addressed the problem of corrosion with cathodic protection, protective coatings, and electrical isolation. However, cathodic protection systems require additional maintenance, which is not necessary with fiberglass. The strength of fiberglass equals that of steel, if installed properly. The installation requirements for steel are very similar to those of fiberglass. Resin and other linings allow increased chemical compatibility for both steel and fiberglass.