Structure of storage tank

Vault

The vault tank is a steel container with a spherical crown and a cylindrical tank. The vault storage tank is simple to manufacture and low in cost, so it is most widely used in many industries at home and abroad. The most commonly used volume is 1000 -10000m 3, and the maximum volume of the domestic vault storage tank has reached 30000m 3.

Tank bottom: the tank bottom is assembled by steel plates, the steel plate in the middle of the tank bottom is the middle plate, and the surrounding steel plate is the edge plate. The edge plate may be a strip plate or an arcuate plate. In general, when the inner diameter of the storage tank is less than 16.5m, the strip edge plate should be adopted, and when the inner diameter of the storage tank is ≥ 16.5m, the arcuate edge plate should be adopted.

Tank wall: The tank wall is formed by welding pairs of multi-ring steel plates and is divided into sleeve type and linear type.

The circumferential weld of sleeve-type tank wall plate is overlapped, and the longitudinal weld is butt joint. This form is mostly used for vault storage tanks, which has the advantage of facilitating the assembly of wall plates in each circle, and it is safer to use the inverted method for construction.

The circumferential weld of the straight-line tank wall plate is butt joint. The advantage is that the overall diameter of the tank wall is the same from top to bottom, which is especially suitable for internal floating roof storage tanks, but the installation requirements of the group are higher and more difficult.

Tank top: the tank top has a plurality of fan-shaped plates welded in pairs to form a spherical crown. The inner side of the tank top is made of flat steel to make reinforcing ribs. Lap welds are used between each fan-shaped plate. The whole tank top is welded with the angle steel ring (or lock) on the upper part of the tank wall plate.

Floating roof type

The floating roof tank is composed of a floating roof on the surface of the medium and a vertical cylindrical tank wall. The floating roof rises and falls with the increase or decrease of the medium storage in the tank. There is an annular sealing device between the outer edge of the floating roof and the tank wall. The medium in the tank is always directly covered by the inner floating roof to reduce the volatilization of the medium.

Tank bottom: the volume of floating roof tank is generally relatively large, and its bottom plate adopts arcuate edge plate.

Tank wall: adopt straight-line tank wall, butt weld should be polished smoothly to ensure smooth inner surface. The upper part of the floating roof tank is open. In order to increase the rigidity of the wall plate, the wind-resistant ring beam and reinforcing ring shall be set on the top of the tank wall according to the wind load in the area.

Floating roof: Floating roof is divided into single disc type floating roof, double disc type floating roof and float type floating roof.

Single-disc floating roof: an annular pontoon composed of several independent cabins, with a single-disc roof on the inner side of the ring. The bottom of the single-disc top plate is reinforced with multiple annular steel rings. Its advantages are low cost and good maintenance.

Double-disc floating roof: it is composed of upper disc plate, lower disc plate and cabin edge plate, and is divided into several independent annular compartments by radial partition plate and circumferential partition plate. Its advantages are large buoyancy and good drainage effect.

Internal floating roof type

The internal floating roof tank is formed by adding a floating roof inside the vault tank. The addition of a floating roof inside the tank can reduce the volatile loss of the medium, and the external vault can prevent rainwater, snow and dust from entering the tank to ensure that the medium in the tank is clean. Such tanks are mainly used for storing light oil, such as gasoline, aviation kerosene, etc. The inner floating roof storage tank is made of straight wall and butt welding of wall plates, and the vault is made according to the requirements of the vault storage tank. At present, the domestic floating roof has two structures: one is the same steel floating roof as the floating roof tank; the other is the aluminum alloy floating roof assembled.

Horizontal

The volume of horizontal storage tanks is generally less than 100m3 and is usually used in production or gas stations. The circumferential weld of horizontal storage tank shall be lapped, and the longitudinal weld shall be butt joint. The ring plates are arranged alternately, taking the singular number, so that the diameter of the end cover is the same. The end cover of horizontal storage tank is divided into flat end cover and dish end cover. The horizontal storage tank with flat end cover can bear 40kPa internal pressure and the horizontal storage tank with dish end cover can bear 0.2Mpa internal pressure. The underground horizontal storage tank must be provided with a reinforcing ring, which is also made of angle steel.