Oil storage tank is a kind of container for storing oil. The common shape of oil tank is vertical cylinder, horizontal cylinder, spherical tank, etc. according to the structure of the top, the vertical cylindrical tank can be divided into truss top tank, powerless moment top tank, beam column top tank, arch roof tank, jacketed tank and floating roof tank, among which the most commonly used are dome top tank and floating roof tank. The dome tank is simple in structure, and is commonly used to store raw oil, finished oil and aromatic products. The floating roof tank is divided into two types: the inner floating roof tank and the outer floating roof tank. The steel floating roof in the tank floats on the oil surface, and rises and decreases with the oil level. Floating roof not only reduces the consumption of oil, but also reduces the risk of fire and air pollution. Especially, the inner floating roof tank has a small evaporation loss, which can reduce the oxidation of air to oil products, ensure the quality of oil storage, and is more favorable for fire protection. The front inner floating roof tank is widely used to store volatile light oil at home and abroad, and it is a kind of oil storage tank which is widely used. Horizontal cylindrical oil tank is also widely used. Because of its ability of bearing high positive pressure and negative pressure, it is conducive to reduce the evaporation loss of oil products and reduce the risk of fire. It can be manufactured in batches in machinery and then transported to the site for installation, easy to carry and remove, and has good mobility. The disadvantage is that the capacity is generally small, the number of use is large, and the area is large. It is suitable for small distribution oil depots, rural oil depots, urban gas stations, army field oil depots or enterprise affiliated oil depots. It is also used as auxiliary oil tank in large oil depot, such as vent tank and metering tank. Spherical tank has the characteristics of pressure resistance and material saving, which is mostly used in LPG system and solvent tank with high pressure.

Welding rotator is an auxiliary equipment in the process of oil storage tank manufacturing, which can greatly improve efficiency and reduce labor force. The whole welding rotator has strong rigidity and stability, beautiful appearance, reliable performance, simple maintenance and long service life.  The two motors and the reducer of the driving frame are controlled by the same frequency converter to realize the stepless speed change and synchronous operation of the two motors. The motor drives the driving wheel through the transmission system. The welding workpiece is placed on the driving wheel and the driven wheel. When the driving wheel is running, the friction between the workpiece and the driving roller drives the workpiece to run. The linear speed of the welding position on the workpiece is the welding speed. The friction between the rotating workpiece and the driven roller drives the driven roller to rotate.