One, Purpose of Storage Tanks: Steel storage tanks are sealed containers used for storing liquids or gases. They are essential and critical infrastructure in industries such as oil, chemical, grain, food, fire protection, transportation, and metallurgy. Steel storage tanks are indispensable in our economic life and play an irreplaceable role in the national economic development. They are specialized equipment for storing various liquid (or gas) raw materials and finished products. Many enterprises cannot operate normally without storage tanks, especially for national strategic material reserves, which rely on various capacities and types of tanks. Most of our oil storage facilities are above ground, with a majority being metallic structures. Two, Classification of Storage Tanks: Due to the different storage media, storage tanks come in various forms. By location: They can be classified into above-ground tanks, underground tanks, semi-underground tanks, offshore tanks, and submarine tanks. By oil type: They can be categorized as crude oil tanks, fuel oil tanks, lubricating oil tanks, edible oil tanks, firewater tanks, etc. By use: They can be divided into production tanks and storage tanks. By form: They can be classified into vertical tanks and horizontal tanks. By structure: They can include fixed-roof tanks, floating-roof tanks, spherical tanks, etc. By size: Tanks over 100 cubic meters are considered large, mostly vertical; those under 100 cubic meters are small, mostly horizontal. Hanging ear steel-lined plastic mixing tanks have good strength and do not deform, making them suitable for storing solutions with high specific gravity. They can be used at low pressure (water pressure: 3 kg, air pressure: 1 kg). They are not suitable for high vacuum conditions and have a maximum operating temperature of 90°C. The combination of steel, mesh, and plastic, formed by rotational molding, offers the mechanical properties of steel tanks and the corrosion resistance, slow scaling, and resistance to microbial growth of plastic tanks, making them ideal for storing acidic, alkaline, saline, and corrosive gas media. The maintenance of hanging ear steel-lined plastic mixing tanks is generally divided into medium repair and major repair. The medium repair cycle is 60 to 120 days, while the major repair cycle is 12 months. For medium repair, the main tasks include eliminating leaks, drips, and other phenomena on the tanks, as well as replacing components that are severely worn or damaged. Major repairs build upon medium repairs, including repairs and restorations, to conduct more comprehensive inspections.