JPH11182790A - Construction method for piping through part of tank roof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the work burden of a worker at a construction site. SOLUTION: A temporary cover 16 is mounted to a flange 17 at the lower end of a sleeve 14 provided at a piping through part of a tank roof 5, by bolt fastening to close in such a way as not to generate air leak, and pressurized air 8 is led into the lower side of the tank roof 5 to perform work of air-raising, air-support, or the like of the tank roof 5 by air pressure. After the work is completed, bolts 18 are unfastened to remove the temporary cover 16, and piping is passed through and arranged through the opened sleeve 14. A cover body fitted to the outside of the piping is then welded to the upper end of the sleeve 14. In this way, the temporary cover 16 need not be mounted on the upper end of the sleeve 14 restricted legally, so that edge preparation conformed to the law can be previously applied to the upper end of the sleeve 14 easily and accurately in a factory or the like. There is therefore no need to cut the upper end of the sleeve 14 at a construction site in order to remove the temporary cover 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a pipe penetration portion of a tank roof.

[0002]

2. Description of the Related Art As shown in FIG. 4, when a low-temperature tank 1 is conventionally constructed, a tank side wall 2 which forms a body portion of the low-temperature tank 1 is completed on a foundation 3, and then the tank bottom 4 is used. Assemble the dome-shaped tank roof 5 and then
A seal member 6 is attached all around the outer edge of the tank roof 5, and a plurality of sets of snatch flocks 9, intermediate rollers 10, and central rollers 11 are temporarily provided in the radial direction on the upper surface of the tank roof 5, near the upper end of the tank side wall 2. A plurality of balance wires 12 having one end fixed thereto are sequentially wound around the snatch flock 9, the intermediate roller 10, and the center roller 11, and then penetrate downward through the center of the tank roof 5 so that the center of the tank bottom 4 is formed. The other end is fixed to the tank, and while the posture of the tank roof 5 is kept horizontal by the balance wires 12 stretched in this way, the pressurized air 8 is introduced by a blower 7 to the lower side of the tank roof 5 by the blower 7. An air-raising method is often employed in which the roof 5 is levitated by air pressure and the tank roof 5 is connected to the upper end of the tank side wall 2.

In the case where concrete is cast on the upper surface of the tank roof 5 connected to the upper end of the tank side wall portion 2 to form a protective layer, the above-described air lasing is performed until the cast concrete is solidified. As in the case of the construction method, an air support construction method of applying air pressure to the underside of the tank roof 5 to support the load on the tank roof 5 is employed.

When the air-raising method or the air-support method is employed as described above, as shown in FIG. 5, various pipes 13 penetrate through a plurality of locations of the tank roof 5 and are indirectly fixed to the tank roof 5. Since the sleeve 14 is open so as to communicate between the inside and the outside of the tank, it is necessary to close the sleeve 14 before applying air pressure to prevent air leakage.

That is, a low-temperature liquefied gas such as LNG or a vaporized gas generated in the tank is passed through the pipe 13 disposed through the tank roof 5.
If the pipe 13 is directly penetrated and fixed,
Due to the heat shrinkage of 3, the stress concentration exceeding the design strength of the tank roof 5 acts on the fixed part, or the fixed part between the tank roof 5 and the pipe 13 designed under normal temperature conditions lowers the temperature to cause low temperature embrittlement and frost. In order to avoid these inconveniences, a pipe 13 is disposed through the tank roof 5 with a sleeve 14 interposed therebetween, and a plate for closing the upper end of the sleeve 14 is provided. Although the pipe 13 is fixed by the lid 15 having a large thickness (high strength), for the air lasing and the air support, the pipe 13 indicated by a two-dot chain line in FIG. Since it is performed in the previous stage, the sleeve 1
4 must be closed with a temporary lid.

[0006]

However, the welded portion between the upper end of the sleeve 14 and the permanent cover 15 has a groove shape defined by law, and the groove formed in accordance with the law has a groove. Since it is virtually impossible to temporarily attach the temporary lid to the upper end of the nozzle 14 so as not to cause air leakage and then remove the temporary lid again without damaging the groove shape, conventionally, as shown in FIG. As described above, the temporary lid 16 is welded and closed to the upper end of the sleeve 14 which has been extended upward in advance, and then air lasing and air support are performed. Thereafter, as shown in FIG. Lid 1
6 is cut to form a groove on the cut end face in accordance with the law again, and the lid 15 is welded and fixed to the upper end of the sleeve 14 when the pipe 13 is permanently installed as shown in FIG. However, cutting off the upper end of the sleeve 14 at the site and performing the groove processing with high accuracy in order to remove the temporary lid 16 in this way has been a heavy work burden for the operator. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a method of constructing a pipe penetration portion of a tank roof capable of reducing the work load on a worker at a site.

[0008]

According to the present invention, a temporary lid is attached to a lower end of a sleeve provided at a pipe penetration portion of a tank roof so as to close the sleeve so that air leakage does not occur, and the sleeve is closed under the tank roof. The required construction work is performed while introducing the pressurized air to the side and supporting the load on the tank roof by air pressure, and after the completion of the construction work, the temporary lid is removed, the sleeve is passed through and the piping is arranged through the sleeve. The present invention relates to a method for constructing a pipe penetration portion of a tank roof, characterized in that a lid externally fitted to a pipe is welded to an upper end of the sleeve.

[0009] In this case, the provisional lid does not need to be attached to the upper end of the sleeve which is restricted by the regulations, so that the upper end of the sleeve can be easily and accurately preformed in accordance with the regulations in a factory or the like. This makes it possible to eliminate the need for on-site beveling of the upper end of the sleeve.

In the present invention, it is preferable that a temporary lid is attached to a flange formed at a lower end of the sleeve by bolting to close the sleeve, and in this case, the temporary lid is merely loosened by bolts. Can be easily removed from the flange at the lower end of the sleeve, so that the work of cutting the lower end of the sleeve together with the temporary lid when removing the temporary lid from the lower end of the sleeve becomes unnecessary.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show an embodiment of the present invention, in which the same reference numerals as in FIGS. 5 to 7 denote the same components.

As shown in FIG. 1, in this embodiment, a sleeve 14 provided at a pipe penetration portion of the tank roof 5 is
The upper end of the sleeve 14 is preliminarily grooved in accordance with regulations at a factory or the like, and the lower end of the sleeve 14 is formed with a flange 17 as shown in FIG.
When a pressurized air 8 is introduced into the lower side of the tank roof 5 to carry out construction work such as air-raising and air support while supporting the load of the tank roof 5 by air pressure, the flange 17 at the lower end of the sleeve 14 is temporarily Cover 1 with bolt 1
The lower end of the sleeve 14 is closed so that air leakage does not occur.

Next, when the construction work by air-raising, air support, etc. is completed, the sleeve 14 is opened by loosening the bolt 18 and removing the temporary lid 16, and thereafter, as shown in FIG. Through piping 1
3 is welded to the upper end of the sleeve 14 so as to close the gap between the upper end of the sleeve 14 and the pipe 13, Is indirectly fixed to the tank roof 5 by the sleeve 14 and the lid 15.

In this manner, the temporary lid 16 does not need to be attached to the upper end of the sleeve 14 which is restricted by the regulations. It can be easily and easily applied, and the beveling of the upper end of the sleeve 14 at the site is not required, so that the work load on the worker at the site can be significantly reduced as compared with the related art.

Further, in the present embodiment, the temporary lid 16 is attached to the flange 17 formed at the lower end of the sleeve 14 by bolting.
The temporary lid 16 can be easily removed from the flange 17 at the lower end of the sleeve 14 simply by loosening the sleeve 8, and there is no need to cut the lower end of the sleeve 14 together with the temporary lid 16 when removing the temporary lid 16 from the lower end of the sleeve 14. Therefore, it is possible to further reduce the work load of the worker on the site.

The method for constructing a pipe penetration part of a tank roof according to the present invention is not limited to the above-described embodiment.
In addition to forming a flange at the lower end of the sleeve and bolting the temporary lid to the flange, the temporary lid may be attached to the lower end of the sleeve by welding. It goes without saying that various changes can be made in.

[0018]

According to the method for constructing a pipe penetration part of a tank roof of the present invention described above, various excellent effects as described below can be obtained.

(I) According to the first aspect of the present invention, it is not necessary to attach the temporary lid to the upper end of the sleeve which is restricted by the law, so that the upper end of the sleeve conforms to the law in advance. Groove processing can be easily and accurately performed in factories, etc.Because the beveling of the upper end of the sleeve on site is not required, the work load of workers on site can be significantly reduced compared to the past. it can.

(II) According to the invention described in claim 2 of the present invention, the temporary lid can be easily removed from the flange at the lower end of the sleeve only by loosening the bolt. Since the work of cutting the lower end of the sleeve together with the temporary lid is not required, it is possible to further reduce the work load of the worker at the site.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where a temporary lid is attached to a lower end of the sleeve of FIG.

FIG. 3 is a cross-sectional view showing a state in which the temporary lid of FIG.

FIG. 4 is a cross-sectional view for explaining the outline of the air lazing method.

FIG. 5 is a cross-sectional view showing the structure of a conventional pipe penetration portion of a tank roof.

FIG. 6 is a cross-sectional view showing a state where a temporary lid is attached to an upper end of the sleeve of FIG. 5;

7 is a cross-sectional view showing a state in which a groove is formed by cutting the upper end of the sleeve of FIG. 6 together with the temporary lid.

[Explanation of symbols]

 5 Tank roof 8 Pressurized air 13 Piping 14 Sleeve 15 Lid 16 Temporary lid 17 Flange 18 Bolt 19 Nut

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hidenori Suzuki 3-2-1, Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. No. 16 Ishikawajima Harima Heavy Industries, Ltd.Toyosu Sogo Office (72) Inventor Shoji Miyazaki 3-16 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd.Toyosu Sogo Office (72) Inventor Naoto Omori 3-16 Toyosu Ishikawajima Harima Heavy Industries, Ltd.

Claims (2)

[Claims] 1. A temporary lid is attached to a lower end of a sleeve provided at a pipe penetration portion of a tank roof to close the sleeve so as to prevent air leakage, and pressurized air is introduced under the tank roof. Perform the required construction work while supporting the load on the tank roof by air pressure, after the completion of the construction work, remove the temporary lid, and through the sleeve through the piping,
A method of constructing a pipe penetration part of a tank roof, comprising welding a lid externally fitted to the pipe to an upper end of the sleeve. 2. The method according to claim 1, wherein a temporary lid is attached to a flange formed at a lower end of the sleeve by bolting to close the sleeve.