SF double-layer tank is the abbreviation of double-layer tank made of reinforced glass. In the mid-1980s, it was first developed by Permatank Company of the United States, and then introduced to Japan by Yutian Industrial Co., Ltd. in 1994, and relevant standards were formulated. Since then, SF double-layer tanks have been widely used. China's double-deck oil tank technology started late, and there is a certain gap with developed countries. However, with the efforts of Shandong North Zhong Yi New Materials Co., Ltd. and other enterprises, the technology has been quite mature and has been used in gas stations of PetroChina, Sinopec and Shell. According to statistics, the application of double-deck tanks in gas stations in developed countries such as Japan, Europe and America has increased from 7. 0% in 1985 to 98% by the end of 2009. SF double-layer tank can be popularized and used so quickly, mainly because of its three advantages: safety, environmental protection, economy and practicality.

1 security

SF double-layer tank has a double-layer structure, and there is a gap between the inner steel shell and the outer reinforced glass fiber layer, so that even if the inner shell leaks, it can ensure that the contained dangerous substances only flow in the gap and will not immediately overflow to pollute the environment; The tank is equipped with advanced leak detector, which can be monitored 24 hours a day. Once there is an internal leak, the detector will generate a buzzer alarm, which will ensure the user to stop using it at the first time and eliminate the potential safety hazard from the root.

2 Environmental protection

The outer glass fiber reinforced plastic of SF double-layer tank ensures that the leakage will not directly pollute the soil and water, and protects the ecological environment of the soil and water. At the same time, the FRP shell can fully protect the internal steel shell from external corrosion. Ordinary single-layer oil tanks are buried in the ground all the year round, corroded by underground water vapor, and their service life is very short, only about 10 years according to environmental calculation. After corrosion, the oil tanks are easy to be damaged and cracked, resulting in leakage of internal items. The glass fiber shell outside the double-layer tank is sprayed by special process to ensure that the outside is completely sealed, and no water vapor will enter the inside to cause corrosion during use. At the same time, glass fiber is an insulator, which will not cause electrolytic corrosion, and can ensure the safe use of double-layer tanks in normal environment for at least 30 years.

3 Economic practicability

The high safety and high environmental protection performance of SF double-layer tank also indirectly reduce the use cost of users. The oil tank is convenient to install, there is no need to build an underground oil storage room, and the oil tank can be directly buried underground for use, which greatly shortens the construction period and reduces the cost input; Effectively protect the environment and avoid the high environmental cost in the later period. However, ordinary single-layer steel oil tanks need maintenance and inspection every year, which increases the maintenance time and cost.

Application prospect of 3 SF double-layer tank in China

With the gradual improvement of China's environmental protection laws and regulations, it is bound to become a trend for gas stations to use this SF double-layer tank with high safety and high environmental protection. GB50 156 20 12 clearly points out that when a buried oil tank needs a double-layer oil tank, double-layer steel oil tank, double-layer FRP oil tank with internal steel and external steel can be used. At the same time, it is also mentioned in the explanation of its provisions that due to the need of environmental protection, double-layer oil tanks with inner steel and outer FRP have been used in China. The price advantage of SF double-layer tank also promotes its popularization and application. Compared with SF double-deck tanks, FF double-deck tanks are too expensive. For example, in the Japanese underground storage tank market, steel single-wall tanks account for 5%, SF double-layer tanks account for 75%, and FF double-layer tanks only account for 5%. Obviously, this is because FF double-deck tanks are expensive. At the same time, SS double-layer tank can not solve the electrochemical corrosion problem of the outer layer, and its service life is short, which can not meet the requirements of energy saving and environmental protection. Therefore, for a long time to come, the Sino-Italian SF double-layer tank in Lubei will dominate the market.