KR20030068770A - A reusable pipe align apparatus when LNG pipe making by welding method in LNG carrier - Google Patents

Abstract

PURPOSE: A pipe aligning apparatus used when welding LNG conveying pipes in an LNG carrier is provided to reduce pipe aligning time by adjusting a position of pipes using a bolt-nut assembly when aligning the LNG conveying pipes. CONSTITUTION: A bolt(25) is vertically moved up and down with respect to a surface of first and second pipes(1,2). The bolt(25) is positioned at an end of an adjusting arm(5) having an L shape. A nut is fixed to an end of the adjusting arm(5). The bolt(25) is screw-coupled into the nut. Central axes of the first and second pipes(1,2) are matched with each other by adjusting the bolt(25). The adjusting arm(5) is welded to a hinge section and a bolt fixing section(50) is formed opposite to the hinge section. A protecting member(60) having a fixing terminal is installed on a predetermined portion of the second pipe(2).

Description

Reusable pipe align apparatus when LNG pipe making by welding method in LNG carrier

The present invention relates to an LNG pipe alignment device of an LNG carrier, and in particular, in connecting LNG transport pipes of an LNG carrier to each other by a welding operation, the position of each pipe is precisely aligned so that each end of the pipe to be connected can be exactly matched. A pipe aligning device for welding an LNG carrier pipe of an LNG Carrier, which can be aligned and can be used repeatedly for the alignment of another pipe after completion of the alignment.

LNG is a colorless, transparent, cryogenic liquid that cools methane-based natural gas to minus 162 ° C and reduces its volume to one-hundredth by 600, commonly referred to as liquefied natural gas.

As LNG emerged as an energy resource, an efficient transportation method that can transport large quantities from the production base to the destination of the demand site was considered to use this gas as energy, and the result was the LNG carrier for the maritime transportation of LNG. appear.

LNG storage tanks are built on large vessels for the storage and transportation of LNG, which is used as a major energy source by liquefying natural gas to cryogenic conditions. The LNG transport pipe used when transferring LNG to LNG storage tanks Since LNG is transported, the welded joints of pipes and pipes must be exactly coincident in the construction of the transport pipe.

When welding the pipes with each other, the welding joints of the transport pipes are broken by repeated expansion and contraction due to the rapid temperature change when LNG is transported and not transported. There is a problem.

Therefore, when manufacturing pipes for LNG transportation, it is important to ensure that the pipes connected to each other are aligned correctly. However, in the conventional case, it is difficult to obtain an accurate alignment because the alignment of pipes and pipes depends on visual observation and experience of each worker.

Due to this problem, the pipe and the connection portion of the pipe requires a reinforcement work, which has a problem of prolonging the work time and increasing weight.

In order to solve the above problem, a technique of attaching a bolt to adjust the position of the pipe at the end of the pipe, and a technique for arranging pipes welded to each other by the bolt has been disclosed.

1 is a view showing a pipe alignment operation method according to the prior art, the adjustment arm (5) of the 'b' shape on the side of the first pipe (1) of the pipe prepared for manufacturing the pipe for LNG transportation by attaching by welding method Then, the upper and lower positions of the bolt 6 are attached to the end of the adjustment arm 5 to be adjustable. In the figure, one adjusting arm is shown for the purpose of showing the shape of the adjusting arm, but the number of adjusting arms in actual work is increased or decreased by the diameter and weight of the pipe.

Referring to FIG. 1, the pipe sorting operation is as follows.

The adjusting arm 5 is fixed to the surface of the first pipe 1 by welding. Adjust the bolt 6 attached to the end of the adjusting arm 5 so that the end of the bolt 6 abuts on the surface of the second pipe 2, and the first pipe 1 and the second pipe 2. Each bolt 6 is adjusted according to the degree of misalignment so that the central axis of the first pipe 1 and the second pipe 2 connected to each other by welding are coincident with each other.

When using the above method, the adjusting arm must be attached by welding to the surface of the first pipe. Pipes used for LNG transportation are heavy and must be welded firmly because of the large loads applied to the adjusting arm during alignment. Therefore, after the pipe alignment work and the pipe connection welding work is completed, it takes a lot of time to remove the adjustment arm that is firmly attached, there is a problem that damage to the surface of the pipe after removing the adjustment arm.

In addition, since the adjustment arm welded to the pipe cannot be used after being removed from the pipe surface, there is a problem in that a lot of cost and materials are consumed in the manufacture of the adjustment arm consumed every time the pipe connection works.

The present invention has been made in order to solve the above problems, in the production of pipes for pipes for the LNG transport ship by connecting pipes and pipes by welding work, the other pipe connected by using a bolt in the state inserted into the pipe end on one side It is an object of the present invention to provide a pipe aligning device for welding LNG transport pipe of an LNG carrier so that the position of the gas can be adjusted.

1 is a view showing a pipe alignment operation method according to the prior art.

Figure 2 is a perspective view showing the form of one embodiment of the adjustment mechanism of the pipe alignment device according to the present invention.

Figure 3 is a front view showing the mounting state of the protective equipment of the pipe alignment device according to the present invention.

4 is a view showing an embodiment of a pipe alignment operation using a pipe alignment device according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: first pipe 2: second pipe

5: adjusting arm 6, 25: bolt

10: adjusting hole 20: nut

40: hinge portion 50: bolt fixing end

60: protector 70: fixed end

Figure 2 is a perspective view showing the form of an embodiment of the adjustment mechanism of the pipe alignment device according to the present invention, the pipe is formed by attaching a bolt that is vertically adjusted up and down with respect to the surface of the pipe at the end of the adjustment arm is formed in a 'b' shape In the alignment device, a hinge part is formed in the ring shape and a hinge part is formed on the surface so that the adjusting arm 5 can be welded and folded and bolted to the opposite side of the hinge part so as not to be detached after being fitted to the end of the pipe. It is shown that the stage 50 is formed to protrude.

Embodiment of the present invention configured as described above is installed and used as follows.

In order to manufacture LNG transport pipe, several pipes having the same diameter are prepared. After inserting the adjusting tool 10 according to the embodiment of the present invention to one end of the first pipe 1, the fixing tool 10 is fixed by using the bolt fixing end 50 so as not to move.

After the adjusting tool 10 is inserted into and fixed to the first pipe 1, the second pipe 2 to be welded is approached to the first pipe 1 side, and then the first pipe 1 and the second pipe. The ends of (2) abut against each other. At this time, the end of the adjustment arm (5) protruding from the side of the adjustment opening (10) is located above the second pipe (1).

In this case, although the first pipe 1 and the second pipe 2 are in contact with each other, since the central axis does not coincide, when the welding operation is performed in this state, the strength of the coupling portion of the completed LNG transport pipe is lowered.

First, since the nut 20 is fixed to the end of the adjustment arm 5, the bolts 25 are inserted into the respective nuts 20, and the respective bolts 25 are rotated to end the bolts 25. Abuts against the surface of the second pipe (2).

In this state, since the central axes of the first pipe 1 and the second pipe 2 are shifted, the respective bolts 25 fitted to the nuts 20 are adjusted to adjust the first pipe 1 and the second pipe ( Make sure the center axis of 2) coincides.

That is, since the diameters of the first pipe and the second pipe are the same, when the central axes coincide, the surfaces of the first pipe and the second pipe must also coincide. If the surfaces of the first pipe and the second pipe do not coincide, the following adjustments are made.

4 is a view showing an embodiment of a pipe alignment operation using a pipe alignment device according to the present invention, when the surface of the second pipe protrudes out of the surface of the first pipe, the side on which the second pipe protrudes Tighten the bolts at the same time and loosen the bolt on the opposite side to allow the second pipe to move. This operation is repeated until the surface of the second pipe coincides with the surface of the first pipe.

When the pipe alignment operation is performed using the adjusting tool as described above, damage may occur on the surface of the second pipe 2 because the end portion of the bolt 25 is in contact with the surface of the second pipe 2.

In order to prevent damage occurring on the surface of the second pipe 2, it is preferable to install and use a protective device 60 of the type shown in FIG.

The protective device 60 is formed in a semicircular shape and fixed ends 70 are formed at both ends by bolts, and the pair of protective devices 60 are coupled to the end side of the second pipe to face the fixed end 70. Insert and fix the bolts (75).

Therefore, after the adjusting device 10 is installed in the first pipe 1, the protective device 60 is installed in a portion where the bolt 25 attached to the adjusting device 10 and the second pipe 2 come into contact with each other. Since the end portion of the bolt 25 abuts the surface of the protective device 60 during the alignment operation, damage to the surface of the second pipe 2 is prevented.

The present invention configured as described above is used to align the pipes welded to each other in the manufacture of LNG transport pipes for LNG carriers, so that the adjusting arm is formed in a ring-shaped adjusting device made to be detachable to the pipes during pipe alignment. By repeatedly using the adjusting arm every time, it is possible to reduce the adjusting arm manufacturing cost and pipe alignment work time.

Claims (2)

In the pipe aligning device is formed by attaching a bolt that is vertically adjusted up and down with respect to the surface of the pipe to the end of the adjustment arm formed in the 'b' shape, it is formed in a ring shape and the adjustment arm (5) is welded fixed to the surface After the hinge portion is formed in the middle portion and inserted into the end of the pipe, the bolt fixing end 50 is protrudingly formed on the opposite side of the hinge portion so as to prevent the bolt from being detached from the LNG transport pipe welding of the reusable LNG carrier. City pipe sorter. 2. The protection device (60) according to claim 1, further comprising a protective device (60) formed in a semicircular shape and having a fixed end (70) fixed at both ends by a bolt at a position of the second pipe (2) where the ends of the bolt (25) abut. Pipe alignment device for welding LNG transport pipe of a reusable LNG carrier characterized in that the installation.