JPH07206085A - Cylindrical liquid-storage tank and side wall panel for liquid-storage tank - Google Patents

Abstract

PURPOSE:To provide a cylindrical liquid storage tank and a side wall panel for liquid storage tank wherein a side wall can be formed without using a guide member and assembling work efficiency of the side wall can be improved. CONSTITUTION:An upper side flange 3 and a lower side flange 4 having different protrusion widths D1, D2 are formed on the upper and lower edges of a plate body 2 respectively. Hence, when side panels 1 for a liquid storage tank, which are vertically adjacent to each other, are welded to each other, the upper side panel 1 can be easily fixed to a position, where the horizontal section of side wall has circularity, by means of a detachable jig, thereby facilitating the assembling work of side wall. And when vertically adjacent panels 1 are brought into contact with each other, a step is formed between the ends of the flanges 3, 4. And since the flanges 3, 4 are welded at the step, the panels 3, 4 are easily joined together by welding, thereby facilitating the assembling work of side panels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid storage tank and a side wall panel for the liquid storage tank.

[0002]

2. Description of the Related Art Generally, a liquid storage tank provided in a factory or the like has a higher strength when it is formed in a cylindrical shape than when it is formed in a rectangular parallelepiped shape, so that it requires less reinforcing material and can be installed at low cost. Are known.

As shown in FIG. 5, the side wall 52 of the cylindrical liquid storage tank 51 is formed by welding a plurality of panels 53 each having a rectangular plate body curved in an arc shape and connecting the panels 53 in the vertical and horizontal directions. Has been formed. Liquid storage tank 5
To form the side wall 52 of No. 1, as shown in FIG. 6, a plurality of panels 53 are welded and laterally connected to each other to form an annular side wall member 54. Then, as shown in FIG. 4, a plurality of guide members 55 are welded to the inside of the upper end of the side wall member 54 at predetermined intervals, and the inside of the guide member 5 is welded to the outside.
The guide member 56 is welded to the position corresponding to 5. Incidentally, FIG.
Only a pair of guide members 55 and 56 are shown in FIG.

The guide members 55 and 56 are welded so that their upper portions are located above the upper ends of the side wall members 54. Further, the guide surfaces 57, 58 facing each other at the upper portions of the guide members 55, 56 are formed in an oblique shape such that the distance between the guide surfaces 57, 58 increases toward the upper ends of the guide members 55, 56. And these guide surfaces 57, 5
When the lower end of another panel 53 is inserted between 8 and
Is guided by the guide surfaces 57 and 58, and its lower end comes to a position corresponding to the upper end of the side wall member 54. That is, the panel 53 is guided by the respective guide members 55 and 56, and the side wall 52 is arranged so as to form a perfect circle.

In this state, the lower end of the panel 53 and the side wall member 5
Weld the upper end of 4 and join them together. Then, the plurality of panels 53 are similarly sequentially welded along the upper end of the side wall member 54, and the adjacent panels 53 in the lateral direction are welded to form another side wall member 54 on the upper side of the side wall member 54.
Then, the side wall 5 of the columnar liquid storage tank 51 is formed by repeating the above-mentioned work and stacking a large number of side wall members 54.
2 is formed in a state of holding a flat circular cross section. And
The guide members 55 and 56 are removed after the side wall 52 is formed.

[0006]

By the way, in order to improve the strength of the cylindrical liquid storage tank 51, it is necessary to make the side wall 52 as close to a perfect circular cross section as possible. Therefore, in the conventional cylindrical liquid storage tank 51, the side wall member 5
The guide members 55 and 56 are welded to the No. 4. The guide member 55, 56 holds the panel 53 welded to the upper end of the side wall member 54 at a position where the side wall 52 has a flat cross section, and by welding in this state, the side wall 52 has a flat cross section. I am trying to become.

However, in order to make the side wall 52 have a flat cross section, the guide members 55 and 56 must be attached by welding, and the work efficiency of assembling the side wall 52 decreases. there were. Also, the side wall 52
The guide members 55 and 56, which had been welded once after the formation of the above-described structure, had to be removed, which required a troublesome removal work.

The present invention has been made to solve the above problems, and an object thereof is to enable the side wall to be formed to have a perfect circular cross section without using a guide member, thereby improving the efficiency of the side wall assembling work. (EN) Provided is a cylindrical liquid storage tank and a side wall panel for a liquid storage tank that can be improved.

Another object of the present invention is to provide a cylindrical liquid storage tank and a liquid storage tank side wall panel which can be manufactured at low cost by reducing the thickness of the side wall.

[0010]

In order to solve the above-mentioned problems, the present invention according to claim 1 is configured such that a quadrangular plate body is curved and formed in an arc shape, and is welded to the vertical and horizontal directions. In a side wall panel for a liquid storage tank that forms a side wall of a cylindrical liquid storage tank by connecting to a plate body, at least both upper and lower edge portions of the plate body are orthogonal to the plate body, and respectively toward the same direction. The main point is to provide a projecting flange.

A second aspect of the present invention is characterized in that, in the liquid storage tank side wall panel according to the first aspect, flanges having different projecting widths are formed at both upper and lower edge portions of the plate body.

According to a third aspect of the present invention, in the side wall panel for a liquid storage tank according to the first or second aspect, the plate body has a semicircular arc shape and extends in the circumferential direction of the plate body. The main point is that the ribs are formed by bending.

According to a fourth aspect of the present invention, a plate body is curved in an arc shape to form a side wall panel for a liquid storage tank, and a plurality of side wall panels for the liquid storage tank are joined by welding in a vertical direction and a horizontal direction. In the cylindrical liquid storage tank having side walls, the side wall panels for the liquid storage tank are provided with flanges on both upper and lower edges in a direction orthogonal to the panel and in the same direction, and with different protruding widths from each other. , When connecting the liquid storage tank side wall panels in the vertical direction, the side wall is formed by welding and connecting the lower flange to the step flange that occurs when the lower flange is brought into contact with the upper flange of another panel. A rib is provided on the side wall panel of the liquid storage tank by bending a rib that extends in the circumferential direction of the liquid storage tank and has a semi-circular cross section. The door and the gist thereof.

[0014]

Therefore, according to the first aspect of the invention, at least the upper and lower edges of the plate body are provided with the flanges projecting in the direction orthogonal to the plate body and in the respective directions. for that reason,
When welding the side wall panels for liquid storage tanks that are vertically adjacent to each other, the upper side panel is arranged such that the side walls have a perfect circular cross section and is easily fixed by a detachable jig.

According to the second aspect of the present invention, since the flanges having different projecting widths are formed at the upper and lower edges of the plate, respectively, when the adjacent liquid storage tank side wall panels are brought into contact with each other, the tips of the flanges are brought into contact with each other. A step portion is formed in the portion. Further, since the flanges are welded at the step portions, the liquid storage tank side wall panels adjacent to each other in the vertical direction are easily joined by welding, and the side wall assembling work is facilitated.

In the invention of claim 3, since the rib is formed on the plate, the strength of the side wall panel for the liquid storage tank is increased,
The thickness of the panel can be reduced as compared with the case where no rib is formed. As a result, the manufacturing cost of the side wall panel for the liquid storage tank is reduced.

According to the fourth aspect of the present invention, the upper and lower edges of the liquid storage tank side wall panel forming the side wall of the columnar liquid storage tank project in the direction orthogonal to the panel and in the same direction, and project toward each other. Flange with different protrusion width was provided. Therefore, when welding the side wall panels for liquid storage tanks that are vertically adjacent to each other, the upper side panel is arranged so that the side wall has a perfect circular cross section and is easily fixed by a detachable jig. Work becomes easy. Further, since a rib having a semi-circular cross-section and extending in the circumferential direction of the liquid storage tank side wall panel is formed by bending and the side wall is formed by the liquid storage tank side wall panel, a rib is formed on the outer periphery of the side wall. To be done. Therefore, the wall thickness of the side wall can be made thinner than in the case where the rib is not formed, and the manufacturing cost of the cylindrical liquid storage tank is reduced while maintaining the strength of the side wall.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
It will be described with reference to FIG. As shown in FIG. 1, the liquid storage tank side wall panel 1 is formed by bending a quadrangular plate 2 into an arc shape. At the upper edge of the plate body 2, an upper flange 3 having a protrusion width D1 is formed on the inner peripheral side of the plate body 2 curved in an arc shape so as to project orthogonally to the plate body 2. Further, a lower flange 4 having a protrusion width D2 protruding in the same direction as the upper flange 3 is formed at the lower edge of the plate body 2. The flanges 3 and 4 are formed so that the protrusion width D1 is larger than the protrusion width D2. still,
In FIG. 1, the upper side of the paper is the upper side of the panel 1 and the lower side of the paper is the lower side of the panel 1.

The plate body 2 is formed with a rib 5 having a semi-circular cross section which extends in the bending direction of the plate body 2 and projects in the direction opposite to the flanges 3 and 4. By forming the ribs 5 on the plate body 2, the strength of the liquid storage tank side wall panel 1 is increased, and the thickness of the panel 1 is reduced by the ribs 5.
It is designed to be thinner than the case where it is not formed. FIG. 3 shows a cylindrical liquid storage tank 6 whose side wall is formed by using the side wall panel 1 for liquid storage tank configured as described above.

The cylindrical liquid storage tank 6 has a cylindrical side wall 7
And a roof member 8 provided on the upper side of the side wall 7. The side wall 7 is formed by stacking a large number of annular side wall members 9 in stages and welding the respective side wall members 9 to join them together. The side wall member 9 is formed by welding a plurality of the panels 1 in the left-right direction and joining them together. Further, since the side wall member 9 joins the panels 1 by welding in the left-right direction, a plurality of ribs 5 are formed on the outer peripheral surface of the side wall 7 along the outer peripheral surface.

Next, a method of assembling the side wall 7 of the cylindrical liquid storage tank 6 will be described. First, a plurality of liquid storage tank side wall panels 1 are welded and joined to each other in the left-right direction to form a side wall member 9 that is the lower end of the cylindrical side wall 7. Then, another panel 1 is arranged on the upper end of the side wall member 9 so that the side wall 7 has a perfect circular cross section. As shown in FIG. 2, the lower flange 4 of the panel 1 is in contact with the upper flange 3 of the panel 1 forming the side wall member 9. Since the protrusion width of the lower flange 4 is smaller than that of the upper flange 3, a step portion 10 is formed at the tip of each of the flanges 3 and 4 in contact with each other.

The panel 1 is fixed to the side wall member 9 by sandwiching the contacting flanges 3 and 4 with a detachable jig 11, and in this state, the step portions 10 form the flanges 3 and 4.
The panel 1 is connected to the side wall member 9 by welding. Further, a plurality of panels 1 are similarly sequentially welded along the upper end of the side wall member 9 to join them to the side wall member 9, and adjacent panels 1 are welded to join together,
Another side wall member 9 is formed on the upper side of the side wall member 9. By repeating the above-mentioned work, a large number of steps of the side wall members 9 are stacked and welded to form the side wall 7 of the cylindrical liquid storage tank 6. Further, the jig 11 that has fixed the panel 1 is removed after the side wall 7 is formed.

As described above in detail, in this embodiment, since the rib 5 is formed on the side wall panel 1 for the liquid storage tank, the wall thickness of the panel 1 can be made thinner than that when the rib 5 is not formed. . Therefore, the manufacturing cost of the panel 1 can be reduced. Further, since the side wall member 9 forming the side wall 7 is formed by welding the plurality of panels 1 on which the ribs 5 are formed and connecting them in the left-right direction, the plurality of ribs 5 are formed along the outer periphery of the side wall 7. It
Therefore, the thickness of the side wall 7 can be reduced while maintaining the strength of the side wall 7 as compared with the case where the rib 5 is not formed, and the manufacturing cost of the cylindrical liquid storage tank 6 can be reduced.

Further, since the upper and lower flanges 3 and 4 are formed at both upper and lower edges of the liquid storage tank side wall panel 1,
The panel 1 can be easily fixed to a position where the side wall 7 has a perfect circular cross section by using the detachable jig 11. That is, unlike the prior art, since the panel 1 can be fixed and welded at an appropriate position without welding the guide member, the work efficiency of the assembling work of the side wall 7 can be improved. Furthermore,
Since the removable jig 11 can be used, the jig 11 can be easily removed without performing a troublesome removal work. Further, since the jig 11 is used, the guide member once welded is not removed unlike the conventional case.
It is possible to prevent damage to the surface of the side wall 7 when the guide member is removed.

Further, since the flanges 3 and 4 are in contact with each other, the contact area between the panels 1 vertically adjacent to each other is larger than in the conventional case, the strength of the contact portion is increased, and the strength of the side wall 7 as a whole is increased. Get higher Further, since the protrusion width D1 of the upper flange 3 is made larger than the protrusion width D2 of the lower flange 4, when the upper flange 3 is brought into contact with the lower flange 4, a step portion 10 is formed at the tip of each flange 3,4. It Since the flanges 3 and 4 are welded at the step portion 10, the welding can be easily performed.

The present invention is not limited to the above-mentioned embodiment, but can be embodied with the following modifications. (1) In the present embodiment, the rib 5 is formed in a semicircular arc shape that projects toward the outside of the side wall 7, but the rib 5 may also be formed in a semicircular arc shape that projects toward the inside of the side wall 7. Good. Also in this case, similarly to the embodiment, the strength of the side wall 7 is increased, and the wall thickness of the side wall 7 can be made thinner than that without the rib 5.

(2) In this embodiment, the flanges 3 and 4 are formed so as to project toward the inner peripheral side of the curved plate body 2, but the flanges 3 and 4 are formed on the outer peripheral side of the plate body 2. You may form so that it may protrude toward. In this case, the flanges 3 and 4 are welded outside the side wall 7, but the panel 1 can be easily fixed to an appropriate position by using the jig 11 as in the embodiment.

(3) In this embodiment, the protrusion width D1 of the upper flange 3 is larger than the protrusion width D2 of the lower flange 4, but the protrusion width D1 of the upper flange 3 is smaller than the protrusion width D2 of the lower flange 4. You may. Also in this case, since the step portion 10 is formed at the tip of each of the flanges 3 and 4, welding can be easily performed by the step portion 10.

(4) Projection widths D1 and D of the flanges 3 and 4
2 may be the same. In this case, the tip of the upper flange 3 is formed in a slanted shape in which the upper end width of the flange 3 is smaller than the projecting width D1, and the tip of the lower flange 4 is slanted in which the lower end width of the flange 4 is smaller than the projecting width D2. To form. Then, when the flanges 3 and 4 are brought into contact with each other, V-shaped grooves are formed at the tips of the flanges 3 and 4, and the flanges 3 and 4 are welded by the V-shaped grooves. That is, the welding can be easily performed by welding the flanges 3 and 4 in the V-shaped groove.

(5) In this embodiment, the liquid storage tank side wall panel 1 in which the flanges 3 and 4 are provided only on the upper and lower edges of the plate member 2 has been exemplified, but the present invention is not limited to this. That is, in the left and right edges of the plate body 2 in the same direction as the flanges 3,
Further, the left side flange and the right side flange may be formed so as to project perpendicularly to the plate body 2, and the projecting width of each flange may be different. In this case, when a plurality of panels 1 are welded and joined to each other in the left-right direction, the left side flange and the right side flange of another panel 1 come into contact with each other, and a step portion is formed at the tip of each flange. This step makes it easier to weld each flange. In addition, each panel 1 adjacent in the left-right direction
Since the contact area is larger than that in this embodiment, the strength of the contact portion is increased and the strength of the entire side wall 7 is further increased.

Further, the left and right flanges may have the same protruding width. Then, the tip of the left flange is formed in a slant shape in which the left end width of the flange is smaller than the projecting width, and the tip of the right flange is formed in a slant shape in which the right end width of the same flange is smaller than the projecting width. In this case, when the left side flange and the right side flange of another panel 1 are brought into contact with each other, a V-shaped groove is formed at the tip of each flange, and the V-shaped groove facilitates welding of the left and right flanges.

(6) In this embodiment, the rib 5 is formed on the side wall 7 by forming the rib 5 on the side wall panel 1 for the liquid storage tank, but the rib 5 may be omitted. In this case, the thickness of the panel 1 increases, but the ribs 5 do not have to be formed, so that the panel 1 can be manufactured more easily.

(7) A plurality of half-moon shaped reinforcing pieces may be arranged inside the rib 5 of this embodiment at a predetermined interval, and the arc portion of each reinforcing piece may be welded to the inner surface of the rib 5. . In this case, the strength of the panel 1 is further increased. Further, since the strength of the panel 1 is increased, the wall thickness of the panel 1 can be reduced as compared with the case where the reinforcing piece is not welded. As a result, the wall thickness of the side wall 7 can be reduced.

(8) A plurality of columns extending vertically may be welded to the inner peripheral surface of the side wall 7 at predetermined intervals. In this case, the strength of the side wall 7 is further increased. Further, since the strength of the side wall 7 becomes high, the wall thickness of the panel 1 can be made thinner than that in the case where the support columns are not welded, and as a result, the wall thickness of the side wall 7 can be made thinner.

Next, other technical ideas grasped by the above embodiments will be described below together with their effects. (1) In the side wall panel according to claim 1, the tip of the flange of the upper edge portion is formed in an oblique shape such that the upper end width of the flange is smaller than the projecting width, and the tip of the flange of the lower edge portion has a lower end width. A side wall panel characterized by being formed in an oblique shape smaller than a protruding width.

With this structure, when the flange at the upper edge comes into contact with the flange at the lower edge of another panel, a V-shaped groove is formed at the tip of each flange. It will be easier.

(2) In the side wall panel according to any one of claims 1 to 3, second flanges projecting in the same direction as the respective flanges are provided at both left and right edge portions of the plate body, and the respective second flanges have different projecting widths. A side wall panel characterized by the above.

With this structure, the contact area between the panels adjacent in the left-right direction becomes large, so that the strength of the contact portion becomes high and the strength of the entire side wall becomes high. (3) In the side wall panel according to any one of claims 1 to 3, the left and right edges of the plate body are provided with second flanges projecting by the same projecting width in the same direction as the respective flanges, and the left side second flange has the same tip end. A side wall panel characterized in that the left end width of the flange is formed in an oblique shape smaller than the protruding width, and the tip of the right second flange is formed in an oblique shape in which the right end width of the flange is smaller than the protruding width.

With this structure, when the left side second flange contacts the right side second flange of another panel, V-shaped grooves are formed at the tips of the left and right second flanges.
It becomes easier to weld both left and right flanges.

(4) In the liquid storage tank according to the fourth aspect, flanges are provided at both upper and lower edges of the side wall panel in a direction orthogonal to the panel and in the same direction, and the protrusion widths are different from each other. When connecting the side wall panels for the liquid storage tank in the vertical direction, the side wall is formed by welding and connecting the lower flange to the step formed when the lower flange is brought into contact with the upper flange of another panel. Liquid storage tank.

In the case of such a construction, the side wall becomes thicker, but welding becomes easier and the side wall assembling work becomes easier. Further, the contact area of each panel adjacent in the vertical direction becomes large, and the strength of the contact portion becomes high and the strength of the side wall becomes high.

(5) In the liquid storage tank according to the fourth aspect, second sidewalls are provided at the left and right edges of the side wall panel, and second flanges projecting in the same direction as the flanges of the upper and lower edges are provided, and the second flanges are different from each other. By forming a protruding width and welding the flanges and the second flange when joining adjacent panels vertically and horizontally to each other by welding the stepped portion that occurs when the flange and the second flange are brought into contact with the flange and the second flange of another panel. A liquid storage tank having a side wall.

With this structure, the contact area between adjacent panels in the left-right direction increases, the strength of the contact portion increases, and the strength of the side wall increases. (6) The side wall panel according to any one of claims 1 to 3, wherein a reinforcing piece formed in a half-moon shape is welded to the inner surface of the rib.

With this structure, the strength of the side wall panel is increased, and the wall thickness of the side wall panel can be reduced as compared with the case where the reinforcing piece is not welded. (7) In the cylindrical liquid storage tank according to claim 4,
Weld a half-moon shaped reinforcement piece on the inside of the rib, or
Alternatively, a column-shaped liquid storage tank is characterized in that a column extending vertically is welded to the inner peripheral surface of the side wall.

With this structure, the strength of the side wall can be increased, and the wall thickness of the side wall can be reduced as compared with the case where the reinforcing piece or the pillar is not welded.

[0046]

As described above in detail, in the invention according to claim 1, at least upper and lower edge portions of the plate body are provided with flanges projecting in the direction orthogonal to the plate body and respectively in the same direction. . Therefore, when the liquid storage tank side wall panels that are vertically adjacent to each other are welded, the upper panel can be easily fixed to the position where the side wall has a flat circular cross section by a detachable jig. As a result, the side wall can be easily assembled.

According to the second aspect of the present invention, since flanges having different projecting widths are formed at both upper and lower edges of the plate body, when the adjacent side wall panels for liquid storage tanks in the vertical direction are contacted, A step is formed at the tip. Further, since the flanges are welded at the step portions, the liquid storage tank side wall panels that are vertically adjacent to each other can be easily connected by welding, and the side wall assembling work can be further facilitated.

In the third aspect of the present invention, since the ribs are formed on the plate body, the strength of the side wall panel for the liquid storage tank is increased, and the thickness of the panel can be made thinner than in the case where the ribs are not formed. it can. As a result, the manufacturing cost of the liquid storage tank side wall panel can be reduced.

According to the fourth aspect of the invention, the upper and lower edges of the liquid storage tank side wall panel forming the side wall of the cylindrical liquid storage tank project in the direction orthogonal to the panel and in the same direction. Flanges having different projecting widths are provided. Therefore, when welding the side wall panels for liquid storage tanks that are vertically adjacent to each other, the upper panel can be easily fixed to the position where the side wall has a flat cross section by a detachable jig, and the side wall assembly work. Will be easier.
Further, since a rib having a semi-circular cross-section and extending in the circumferential direction of the liquid storage tank side wall panel is formed by bending and the side wall is formed by the liquid storage tank side wall panel, a rib is formed on the outer periphery of the side wall. To be done. Therefore, the wall thickness of the side wall can be made thinner than when the rib is not formed,
The manufacturing cost of the cylindrical liquid storage tank can be reduced while maintaining the strength of the side wall.

[Brief description of drawings]

FIG. 1 is a perspective view showing a side wall panel for a liquid storage tank in this embodiment.

FIG. 2 is a cutaway perspective view showing a contact state of liquid storage tank side wall panels that are vertically adjacent to each other.

FIG. 3 is a perspective view showing a cylindrical liquid storage tank of the present embodiment.

FIG. 4 is a cutaway cross-sectional view showing a state in which conventional side wall panels for a liquid storage tank which are vertically adjacent to each other are welded to each other.

FIG. 5 is a perspective view showing a conventional cylindrical liquid storage tank.

FIG. 6 is a perspective view showing a side wall formation state in a conventional cylindrical handle liquid storage tank.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid storage tank side wall panel, 2 ... Plate body, 3 ... Upper flange, 4 ... Lower flange, 5 ... Rib, 6 ... Cylindrical liquid storage tank, 7 ... Side wall, 10 ... Step part, D1 ... Projection width , D2 ... Projection width.

Claims (4)

[Claims] 1. A side wall (7) of a cylindrical liquid storage tank (6), which is formed by curving a rectangular plate (2) in an arc shape and is welded and connected in the vertical and horizontal directions. ) Forming a side wall panel for a liquid storage tank, a flange (3) projecting in a direction orthogonal to the plate body (2) and at the same time in at least upper and lower edges of the plate body (2). , 4) are provided on the side wall panel for a liquid storage tank. 2. The side wall panel for a liquid storage tank according to claim 1, wherein the upper and lower edges of the plate member (2) have mutually projecting widths (D1, D2).
) Different flanges (3, 4) are formed on the side wall panel for a liquid storage tank. 3. The liquid storage tank side wall panel according to claim 1, wherein the plate body (2) extends in the circumferential direction of the plate body (2) and has a semi-circular cross section. A side wall panel for a liquid storage tank, characterized in that the rib (5) is formed by bending. 4. A plate (2) is curved in an arc shape to form a liquid storage tank side wall panel (1), and the plurality of liquid storage tank side wall panels (1) are welded in the vertical and horizontal directions. A columnar liquid storage tank having side walls (7) connected to each other, in the upper and lower edges of the liquid storage tank side wall panel (1) in a direction orthogonal to the panel (1) and in the same direction. The flanges (3, 4) projecting toward each other and having different projection widths (D1, D2) are provided, and when connecting the liquid storage tank side wall panels (1) in the vertical direction, the lower flange (4) is replaced by another panel ( The side wall (7) is formed by welding and joining at the step portion (10) generated when the upper side flange (3) of (1) is brought into contact with the side wall panel (1) for each liquid storage tank. Same panel Circumferentially extending and sectional semicircular rib (5) cylindrical liquid storage tank, characterized in that a rib (5) on the side wall (7) by bending form (1).