Classification And Characteristics of Storage Tank Inversion Method

Storage tank construction methods usually have two main loading method and inversion method, for the capacity of more than 10,000 cubic meters of floating roof tank, the domestic has been limited to the water float loading method and Angle hand frame loading method, small and medium-sized capacity storage tank using inversion method. Compared with a large number of high-altitude operations in the construction of the forward installation method, the inverted installation method has the advantages of low-altitude operation, convenient operation and high safety. With the development of large storage tanks, it has become an inevitable trend to research and develop the inversion construction technology of large storage tanks.

At present, inversion method has been widely used in domestic storage tank construction, vertical vault storage tank construction, mostly using center column inversion method, air top inversion method, hydraulic jacking inversion method construction, one of them has the following advantages:

1) The construction speed is fast, the work efficiency is high, and the quality is easy to ensure.

2) Avoid high-altitude work, do not need to set scaffolding, large scope of construction activities, and safe.

3) The lifting equipment and construction tools required are relatively simple.

I. Center column inversion method

The construction process of the center column inversion method is:

Install tank bottom plate → erect center column → Install top panel and welt Angle → Install tank top panel → Install second layer (from top to bottom) panel → Lift top panel to weld second layer panel → Install third layer panel until all panel is installed → Install accessories and accessories.

The key to this approach is the central column. The center column is composed of a base, a center column, an umbrella stand and a column head. It is an upright tubular single mast that only bears axial pressure and is generally made of seamless steel pipe.

The center column is generally made of steel pipe, the center column should always maintain the plumb state after being erected, and the top of the column is provided with 4-6 wind ropes in order to find and fix, and the force of the wind rope should be basically balanced. The column head of the center column and the umbrella stand are connected with each other through the pulley block, and through the lifting of the oil tank. The center column is generally hoisted by two sets of hanging blocks, and the hanging position of the main hanging block on the top of the center column should be based on the principle that the center column is not subject to eccentric moment. The umbrella frame is equipped with two suspension rods made of steel pipes, each of which can be rotated within 180°, and the end is connected with the stigma by a pulley block with a steel wire rope edge

The center column leads from the bottom of the tank to the winch drum outside the tank. The boom is used for lifting wall panels, assembling tank tops and winding ladders. ,

Advantages and disadvantages of center column inversion method:

Advantages: Easy to operate, simple and economical.

Disadvantages: When the construction of large volume of storage tanks, due to a lifting weight is too large, easy to deformation, difficult to operate.

II. Air jacking inversion method

In the construction of large diameter storage tanks, air jacking method is often used to implement flip, which is also called inflatable jacking (or air blowing) installation.

Air jacking assembly of oil tank is based on the structural characteristics of the tank itself (with arched top), using air pressure to float the tank. The flip construction method is used to complete the assembly of the wall panels of the vertical vault oil tank. According to the construction requirements, the air is pumped into the tank by the blower. When the lifting force of the air in the tank exceeds the sum of the weight of the tank and the friction force, the tank is raised. When the tank is raised to a predetermined height, the air supply volume is controlled to keep the air pressure in the tank stable (at this time, the intake volume is equal to the deflated amount), at this time, the tank is suspended at a fixed height, and the lower section wall panel can be assembled.

Advantages and disadvantages of air-blown jacking inversion method:

Advantages: save labor, simple construction equipment, reduce project cost.

Disadvantages: technical difficulty, a little careless will cause "roof" accident.

III. Construction technology of hydraulic jacking method

Lay tank bottom plate -- install jack -- surround the top ring panel and edge Angle steel, install center frame -- Install tank top plate -- lift the first ring panel and top plate -- surround the second ring panel -- return oil drop and weld the second ring panel -- drop the expansion ring and bracket -- continue to lift until all tank assembly is welded.

Advantages and disadvantages of hydraulic jacking inversion method:

Advantages: large lifting capacity, wide application range, uniform lifting force, easy operation, safe and reliable

Disadvantages: High one-time input cost

IV. Other inversion methods

There are other forms of inversion, such as the spiral method of assembling steel storage tanks, which uses the principle of screw thread rotation to rise (or fall). The group rod hoisting method uses lifting steel pipes distributed all around the tank wall, and the upper part is suspended by hand hoist, which is used to lift the tank body and flip the oil tank.

Tank construction requires a variety of machines and materials, such as tank welders, hydraulic jacks, etc. WINCOO ENGINEERING CO.,LTD can provide, welcome to our website:www.sino-wincoo.com