Methods That Can Be Used When Installing Large Oil Tanks

There are two main types of oil tanks: arch roof and floating roof. The arch roof oil tank is less used because of the complicated production and installation process and the large consumption of steel. Relatively speaking, the production and installation construction technology of floating roof tank is simple, and it is widely used in the installation of large oil tank. According to the different installation order, the main installation methods of oil tank installation and inversion method, according to the different means of installation, There are two main types of oil tanks: arch roof and floating roof. The arch roof oil tank is less used because of the complicated production and installation process and the large consumption of steel. Relatively speaking, the production and installation construction technology of floating roof tank is simple, and it is widely used in the installation of large oil tank. 

According to the different installation order, the main installation methods of oil tank installation and inversion method, according to the different means of installation, can be divided into internal scaffolding installation method, water floating inversion method, inflatable jacking inversion method, hand hoist inversion method, mechanical lifting (electric hoist) inversion method, hydraulic lifting inversion method and other methods, the corresponding construction technology and advantages and disadvantages are as follows.

1. Internal scaffolding installation method

Temporary scaffolding is used to assist the assembly and welding of each circle of tank walls, that is, after the construction of tank bottom plate, temporary scaffolding is set up on it, and the tank walls are installed and welded layer by layer. During construction, the inner scaffold can be hung on the wall panel, and the outer scaffold can be hung on the top of the wall panel to form a circular walk along the wall panel. The advantage is that the construction is flexible and convenient through the operation of the workbench. The wall panel and the floating roof group can be carried out at the same time, and the construction period is better improved. The disadvantage is that temporary supports and scaffolds need to use a lot of materials, which is not conducive to site layout and management; When working at altitude, the working surface is narrow and the controllability is low.

2. Water floating inversion method

There is no need to add internal scaffolding and temporary supports, and the buoyancy of the water is used to raise the floating roof and complete the panel assembly layer by layer from the bottom to the top. After the assembly and welding of the tank bottom plate and the bottom ring wall plate are completed, the floating roof can be welded and water can be filled into the tank. By setting T-frame and hanging basket on the float tank, the assembly and welding are carried out layer by layer. The advantage is that the water pressure is slowly increased, which is conducive to the balance of foundation and tank bottom pressure, and the settlement difference is reduced. No scaffolding and temporary supports are required to save materials. The disadvantage is that the water consumption is very large, and the oil tank needs to be soaked in water all the time, which is easy to cause rust of the steel plate.

3. Inflatable jacking inversion method

Similar to the water float method, the assembly and welding of the tank bottom plate and the bottom ring wall plate should be completed before aeration, and the blower is used to supply air to the floating top. By overcoming the weight of the floating top and the friction between the wall plate and the wall plate, the tank body is slowly raised, and the ring plate is installed layer by layer from top to bottom. The advantage is that through a complete set of equipment, the tank can be slowly raised, without high-altitude work, and assembly and welding are convenient. The disadvantage is that this method has many equipment, complex installation, large labor consumption, needs a better sealing device, and the cost is more expensive.

4. Mechanical lifting (electric hoist) inversion method

First, the expansion ring is made by using auxiliary tools such as jacks and fixed on the inner wall of the wall plate, so that the expansion ring and the tank body become one. After the expansion ring is lifted to the predetermined position by the electric hoist device, the group of the upper and lower ring wall panels is set, and the whole assembly and welding are completed by the expansion ring. The advantages are simple construction technology, easy to operate, good control of project quality and construction schedule, low cost, high construction efficiency and good control. The disadvantage is that it needs to be controlled manually, which is time-consuming and laborious. And now the labor costs are more expensive, increase a lot of cost input, and the construction hidden dangers are larger.

5. Hydraulic lifting inversion method

Through a set of hydraulic lifting device with the lifting of the tank body, the oil pump is used to transport hydraulic oil to the jack cylinder through the oil pipe to generate the lifting force, and the tank body is assembled and welded layer by layer through the expansion ring. The advantages are time-saving, stable, reliable, adaptable and good construction quality. The disadvantage is that the cost is relatively high, the one-time investment is large, and it is generally used in the upgrading of very large oil tanks. 

Finally, the selection of construction methods should be combined with the actual site conditions such as tank volume, project cost and construction period.