Advantages and Production Process of SF Double-Layer Storage Tanks
SF, which stands for Steel-Fiber Reinforced Plastic (FRP) Double-Layer Structural Oil Storage Tank, is a double-layer storage tank formed by adding an FRP (Fiber Reinforced Plastic) anti-seepage sleeve on the outer layer of a single-layer steel oil tank. There is a continuous gap between the steel inner tank and the FRP outer tank.
Structural features of San Francisco:
Double-layer composite structure: Composed of a steel inner tank and a glass fiber reinforced plastic (FRP) outer tank, with a certain gap between the two layers, creating an independent monitoring space.
Inner layer: The inner tank is made of high-strength steel, suitable for storing oil products; the outer tank is made of FRP material, which is corrosion-resistant, anti-aging, and can adapt to complex environments.
Outer layer: The thickness of the reinforced glass fiber layer exceeds 4 millimeters. It has excellent compressive strength and seismic resistance, as well as corrosion resistance and resistance to electrochemical corrosion.
Gap monitoring design: The double-layer gap can be filled with inert gas or a monitoring system can be installed. The leak detector conducts real-time monitoring 24 hours a day. An alarm is triggered when the liquid level at the bottom of the gap is detected, thereby enhancing safety.
Material characteristic combination: The inner tank is made of high-strength steel, suitable for storing oil products; the outer tank is made of FRP material that is corrosion-resistant, anti-aging and adaptable to complex environments.
Overall sealing: The joints and welds of the tank body have been specially treated to ensure the sealing performance of the double-layer structure and reduce the risk of leakage.
Compact structure: The integrated design makes its size similar to that of traditional single-tank storage vessels, saving installation space and facilitating transportation and on-site construction.
Safety Function
If the inner tank of the double-layer oil tank leaks, a certain pressure of gas or detection liquid will enter the atmospheric pressure inner tank; the pressure or liquid level in the double-layer gap will change, triggering an audible and visual alarm. Since the outer tank remains intact, the leaked liquid will not escape outside after flowing into the double-layer gap, thus ensuring the safety of the stored liquid, soil and groundwater.
If the outer tank leaks, a certain pressure of gas or detection liquid will seep into the soil through the double-layer gap. Similarly, the pressure or liquid level in the double-layer gap will also change, triggering an audible and visual alarm. At this time, since the inner tank is intact, the stored liquid is safe; only if the gas or detection liquid seeps into the soil, then the soil and groundwater are also safe.
Since the storage liquid in the inner tank is a different medium from the soil and groundwater that the outer tank comes into contact with, the corrosion rate of the tank material is also different. Therefore, the probability of simultaneous leakage is almost zero. Thus, it can prevent the leakage of the stored liquid from the tank, thereby achieving production safety and environmental protection.
The SF double-layer oil tank is easy to install, significantly shortening the construction period and reducing the investment cost. The remote monitoring system facilitates regular daily inspections and digital control, eliminating the need for complex manual operations. The protection requirements of the SF double-layer oil tank are only one-tenth of those of ordinary oil tanks, greatly saving maintenance investment costs. The SF double-layer oil tank has high economic benefits and good environmental performance, effectively protecting energy and avoiding serious hazards and losses caused by energy leakage.
The price advantage of SF double-layer oil tanks has also promoted their popularization and application. Compared with SF double-layer oil tanks, FF double-layer oil tanks are too expensive. For instance, in the underground storage tank market in Japan, steel single-layer oil tanks account for only 5%, while SF double-layer oil tanks account for as high as 75%, and FF double-layer oil tanks account for only 5%. Clearly, this is because FF double-layer oil tanks are too expensive. At the same time, stainless steel double-layer oil tanks cannot solve the problem of electrochemical corrosion on the outer layer, have a short service life, and cannot meet the requirements of energy conservation and environmental protection. Therefore, SF double-layer oil tanks will still hold a leading position in the market for a long time in the future.
Production flow chart
Steel shell welding → Installation of flange accessories → Shell leakage test → Sandblasting and rust removal of the outer surface → Bottom layer anti-rust spraying → Isolation film treatment → Overall FRP spraying of the shell → Drying → Special components FRP treatment → Drying → Inspection of membrane thickness gap formation → Gap pressure and depressurization test → Qualified → Storage
