SF double-walled tank is short for steel-reinforced glass double-walled oil tank

It was first successfully developed by a US company in the mid-1980s, then introduced to Japan and improved by a Japanese industrial corporation in 1994, and related standards were formulated. Since then, SF double-walled tanks have been widely promoted and used.

China's double-walled oil tank technology started relatively late and lags behind developed countries. However, thanks to the efforts of companies such as Sichuan Xinfu Petroleum Equipment Co., Ltd., the technology has become quite mature and is used in gas stations of CNPC, Sinopec, Shell and other companies. According to statistics, the application of double-walled tanks in gas stations in developed countries such as Japan and Europe and America increased rapidly from 7.1% in 1985 to 98% at the end of 2015.

The rapid promotion and use of SF double-walled tanks is mainly due to its three major advantages: safety, environmental protection, and economic practicality:

Safety

The double-walled structure of the SF double-walled tank leaves a gap between the inner steel shell and the outer reinforced fiberglass layer. Even if the inner shell leaks, the dangerous goods will only flow in the gap and will not immediately overflow to the outside to pollute the environment; the tank is equipped with an advanced leak detection instrument that can monitor it 24/7. Once an internal leak occurs, the detector will produce a buzzer alarm, ensuring that the user stops using it immediately, fundamentally eliminating the safety hazard.

Environmental Protection

The outer FRP of the SF double-walled tank ensures that the leaked material will not directly seep and pollute the soil and water sources, protecting the ecological environment of the soil and water. At the same time, the FRP outer shell can fully protect the inner steel shell from external corrosion. Ordinary single-walled oil tanks are buried underground for many years and are corroded by electrolysis due to erosion by groundwater vapor, so their service life is very short, only about 10 years depending on the environment, and the oil tank is easily damaged and cracked after corrosion, leading to leakage of internal materials; while the fiberglass outer shell of the double-walled tank is injection-molded with special technology, ensuring complete external sealing, and no water vapor will enter the inside during use to cause corrosion. At the same time, fiberglass is an insulator and will not cause electrolytic corrosion, ensuring that the double-walled oil tank can be used safely for at least 30 years under normal conditions.

Economic Practicality

The high safety and environmental protection performance of SF double-walled tanks also indirectly reduce the user's operating costs. The oil tank is easy to install and does not require the construction of an underground oil storage room. The oil tank can be directly buried underground for use, greatly shortening the construction period and reducing cost investment; effective environmental protection eliminates high later environmental protection costs. Ordinary single-walled steel oil tanks need annual maintenance and inspection, increasing maintenance time and cost.

Application Prospects of SF Double-Walled Tanks in China

With the gradual improvement of China's environmental protection laws and regulations, the use of SF double-walled tanks with high safety and environmental protection in gas stations will inevitably become a trend. GB501562012 clearly points out: when buried oil tanks need to use double-walled oil tanks, double-walled steel oil tanks, double-walled fiberglass reinforced plastic oil tanks, and inner steel outer fiberglass reinforced plastic double-walled oil tanks can be used. The text also mentions the inner steel outer fiberglass reinforced plastic double-walled oil tanks that are currently being used in China due to environmental protection needs. The price advantage of SF double-walled tanks also promotes its promotion and application. Compared with SF double-walled tanks, FF double-walled tanks are too expensive. In the Japanese underground tank market, single-walled steel tanks account for 5%, while SF double-walled tanks account for as much as 75%, and FF double-walled tanks only account for 5%. This is obviously because the price of FF double-walled tanks is too high; at the same time, SS double-walled tanks cannot solve the problem of electrochemical corrosion of the outer layer, have a short service life, and cannot meet the requirements of energy saving and environmental protection.