JP2012122516A - Method of separating and connecting piping, and piping connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently replace, repair or modify a piping and carry out other tasks of main equipment when the piping attached to a heavy object is connected with the main equipment.SOLUTION: The method of separating, from main equipment, a piping connected with the main equipment and attached to a heavy object and again connecting the piping to the main equipment includes separating the piping from the main equipment (step S2), then moving the piping together with the heavy object to a place separate from a place where the main equipment is disposed (step S4), replacing, repairing or modifying the piping at the separate place (step S5), and moving the piping which has been replaced, repaired or modified together with the heavy object and again connecting the piping to the main equipment (step S6).

Description

  The present invention relates to a pipe separation and connection method in which a pipe connected to a main device and attached to a heavy object is separated from the main device and the pipe is connected to the main device again. Moreover, this invention relates to the piping connection part structure which comprises the connection part of 1st and 2nd piping.

  FIG. 1A shows a pipe structure in which a pipe 31 attached to a heavy article 9 is connected to the main device 3.

  In the example of FIG. 1 (A), the main body device 3 is a reactor pressure vessel (RPV: Reactor Pressure Vessel) provided in a nuclear power plant. The reactor pressure vessel 3 is disposed in the containment vessel 29. On the top of the storage container 29, a heat insulating stand 9 (heavy object) capable of opening and closing the opening 29 a at the top of the storage container 29 is provided. A heat insulating material for holding heat in the storage container 29 is incorporated in the heat insulating rack 9. In addition, a reactor well 8 is provided in the upper part of the reactor pressure vessel 3. The reactor well 8 is filled with water for shielding radiation. The piping 31 is attached to the heat retaining stand 9 that is a heavy object. The piping 31 is, for example, for extracting air from the reactor pressure vessel 3.

  In addition, there exists the following patent document 1 as a prior art document of this application. In Patent Document 1, when exchanging pipes connected to each other, a jig is attached to a flange that is a connecting portion, and a new pipe is produced based on the jig.

Japanese Patent Laid-Open No. 10-311458

  However, the piping structure of FIG. 1 has the following problems (1) and (2).

(1) There is a case where it is desired to perform the replacement, repair or remodeling work of the piping 31 and other work related to the main body equipment (for example, repair work of a structure provided near the main body equipment) independently of each other (for example, simultaneously). is there. However, since there are heavy objects that take up space in the vicinity of the main device, it is difficult to secure a space for performing both operations simultaneously. For this reason, the schedule of one work is restricted by the schedule of the other work.

  In the example of FIG. 1A, when exchanging, repairing, or remodeling the piping 31 and other operations in the reactor well 8, the work schedule such as replacement of the piping 31 is set in the reactor well 8. Will be constrained by other work schedules. The piping 31 is installed in the thermal insulator 9 that is installed in the reactor well 8 and takes a space. Therefore, a sufficient space is secured in the reactor well 8 for simultaneously performing work such as replacement of the piping 31 and other work in the reactor well 8 (for example, repair work for the reactor well 8 itself). Difficult to do. Therefore, the replacement, repair or modification work of the piping 31 and other work in the reactor well 8 cannot be performed at the same time. Will be constrained by the schedule of work.

(2) In FIG. 1 (A), when the pipe 31 is connected to the pipe 33 and the flanges 31a and 33a serving as the connecting portions of the pipes 31 and 33 are provided, The flanges 31a and 33a may be damaged at the time of separation or connection. That is, since the pipe 31 is attached to the heavy object 9 (the heat retaining base 9), when the pipe 31 is moved together with the heavy object 9 when the pipes 31 and 33 are separated or connected, the weight of the heavy object 9 is increased. There is a possibility that the flanges 31a and 33a are rubbed with each other by a large force corresponding to the thickness, and as a result, the flanges 31a and 33a may be damaged.

  For example, as shown in FIG. 1B, when unevenness is formed on the connection surfaces of the flanges 31a and 33a, the flanges 31a and 33a are more easily damaged by the unevenness. FIG. 1B is a partially enlarged view of the vicinity of the flanges 31a and 33a in FIG. 1A, and shows a state where the flanges 31a and 33a are separated from each other. In the example of FIG. 1B, an annular groove 37 into which the annular gasket 35 is inserted is formed on the connection surface of the flange 33a. The gasket 35 is sandwiched between the bottom surface of the annular groove 37 and the annular protrusion 39 formed on the connection surface of the flange 31a. In this state, the flanges 31a and 33a are joined to each other, so that a seal is made at the connection location of the flanges 31a and 33a. When the annular protrusion 39 and the flange 33a are rubbed, the annular protrusion 39 and the flange 33a are damaged.

  Therefore, a first object of the present invention is to solve the above-mentioned problem (1). That is, the first object of the present invention is to efficiently perform exchange, repair or modification work of piping and other work related to the main device when the pipe attached to the heavy object is connected to the main device. There is in doing so.

  The second object of the present invention is to solve the above-mentioned problem (2). That is, when the two pipes are connected via a flange, the second object of the present invention is to move one pipe to which the heavy article is attached together with the heavy article, thereby moving one pipe to the other. It is an object of the present invention to provide a pipe connection portion structure that prevents a flange from being damaged when separating from one pipe or when connecting one pipe to the other pipe.

In order to achieve the first object described above, according to the present invention, a pipe which is connected to a main device and attached to a heavy object is separated from the main device, and the pipe is connected to the main device again. A pipe separation and connection method,
(A) Move the piping so as to be disconnected from the main device,
(B) Next, the piping is moved together with the heavy object to a location different from the installation location of the main device,
(C) Replace, repair or modify the piping at the other location,
(D) A pipe separation and connection method is provided, wherein the pipe that has been replaced, repaired or modified is moved together with the heavy object to the installation location of the main device, and the pipe is reconnected to the main device. Is done.

According to a preferred embodiment of the present invention, the pipe is one of a first pipe and a second pipe connected to each other,
The first and second pipes are provided with flanges serving as connection portions therebetween, and the flanges of the first pipes extend in the axial direction of the first and second pipes at the connection portions. A plurality of pins are provided, a plurality of guide holes extending in the axial direction are formed in the flange of the second pipe, and the plurality of pins are inserted into the plurality of guide holes The flanges of the first and second pipes are butted together and connected,
The movement of the one pipe in (A) is performed while being guided in the axial direction by the fitting of the pin and the guide hole, whereby the one pipe is connected to the first and second pipes. Separate from the other pipe.

Preferably, in (A), the one pipe is moved away from the other pipe by moving the one pipe relative to the other pipe and the heavy object,
Said (B) is performed in the state which fixed said one piping to the said heavy load.

  According to a preferred embodiment of the present invention, the main body device is a reactor pressure vessel, and the heavy object is a heat-retaining stand that covers the reactor pressure vessel from above.

According to a preferred embodiment of the present invention, the flanges of the first and second pipes each have a connection surface that is abutted against each other,
Of the connection surface of the flange of the first pipe and the connection surface of the flange of the second pipe, an annular groove is formed on one side, and an annular protrusion is formed on the other side.
Before performing (A), a gasket is disposed between the groove and the protrusion, and the gasket is sandwiched between the bottom surface of the groove and the protrusion.

  Preferably, a mark indicating the position of the one pipe with respect to the axial direction is attached to the heavy object before (A).

Moreover, in order to achieve the second object described above, according to the present invention, a pipe connection part structure constituting a connection part of the first and second pipes,
The first and second pipes are provided with flanges serving as connection portions therebetween, and the flanges of the first pipes extend in the axial direction of the first and second pipes at the connection portions. A plurality of pins are provided, a plurality of guide holes extending in the axial direction are formed in the flange of the second pipe, and the plurality of pins are respectively inserted into the plurality of guide holes. A pipe connection part structure is provided in which the flanges of the first and second pipes are butted and connected in a state.

  According to the pipe separation and connection method of the present invention described above, the pipe is moved together with the heavy object to a place different from the place where the main device is arranged, and the pipe is replaced and repaired at the other place. Or make modifications. Therefore, the replacement, repair or modification of the pipe and other work related to the main body device can be performed independently of each other. Therefore, the replacement, repair, or modification of the pipe and other work related to the main device can be performed efficiently (for example, simultaneously).

  Further, according to the pipe connection portion structure of the present invention described above, the flange of the first pipe is provided with a plurality of pins extending in the axial direction of the pipe at the connection portion of the first and second pipes. A plurality of guide holes extending in the axial direction are formed in the flange of the second pipe, and the plurality of pins are inserted into the plurality of guide holes, so that the first and second pipes are separated from each other. Alternatively, when the connection is made, one pipe is separated or brought close to the other pipe while being guided in the axial direction by fitting the pin and the guide hole. Therefore, at this time, the first and second pipes are prevented from being displaced from each other in the direction orthogonal to the axial direction. Thereby, the flanges of the first and second pipes are prevented from being rubbed and damaged.

The case where the 1st and 2nd piping is provided in the nuclear power plant is shown. The case where the piping connection part structure by embodiment of this invention is applied to piping connected to the reactor pressure vessel of the nuclear power plant is shown. The connection part vicinity of the 1st and 2nd piping is shown. It is IV-IV arrow line view of FIG. 2 (B), and shows piping support. It is a flowchart which shows the piping separation connection method by embodiment of this invention. The modification of a pipe connection part structure is shown.

  A preferred embodiment of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

(Piping connection structure)
The piping connection part structure 10 by embodiment of this invention is demonstrated. FIG. 2A shows a case where the pipe connection part structure 10 according to the embodiment of the present invention is applied to the pipe connected to the nuclear reactor pressure vessel 3 of the nuclear power plant. 2B is a partially enlarged view of FIG. 2A, and FIG. 2C is a cross-sectional view taken along the line CC in FIG. 2B.
The pipe connection part structure 10 is for connecting or separating the first and second pipes 5 and 7 connected to each other so that the flanges 5a and 7a that are the connecting parts of the pipe connection part structure 10 do not rub against each other. It is.
The pipe connection part structure 10 includes first and second pipes 5 and 7, a heavy object 9, a guide member 11, and a pipe support 13.

The first and second pipes 5 and 7 are provided with flanges 5a and 7a serving as connection portions therebetween. FIG. 3A is a partially enlarged view of FIG. 2B and shows a structure near the flanges 5a and 7a. The flange 5a of the first pipe 5 is provided with a plurality of pins 15 extending in the axial direction (hereinafter simply referred to as the axial direction) of the first and second pipes 5 and 7 at the connection portion of the pipes 5 and 7. Yes. A plurality of guide holes 17 extending in the axial direction are formed in the flange 7 a of the second pipe 7. A plurality of pins 15 are inserted in the plurality of guide holes 17 in the axial direction, respectively. In this state, the flanges 5a and 7a of the first and second pipes 5 and 7 are abutted and connected. The pipes 5 and 7 are, for example, for extracting air from the reactor pressure vessel 3.
The pin 15 is inserted into each guide hole 17 with a slight gap. Thereby, the pin 15 and the guide hole 17 allow relative movement of the first and second pipes 5 and 7 in the axial direction by mutual fitting, and the first and second in the direction orthogonal to the axial direction. The relative movement of the pipes 5 and 7 is restricted.
In FIG. 3A, each pin 15 passes through the flange 5a, but is integrally coupled to the flange 5a. Therefore, each pin 15 and the flange 5a do not move with respect to each other in the axial direction. Each pin 15 and the flange 5a should not move relative to any direction other than the axial direction.

  The flanges 5a and 7a of the first and second pipes 5 and 7 respectively have connection surfaces 19 and 21 that are connected to each other. Of the connection surface 19 of the flange 5a of the first pipe 5 and the connection surface 21 of the flange 7a of the second pipe 7, one (the connection surface 21 in the example of FIG. 3) has a central axis C of the pipes 5 and 7. An annular groove 23 surrounding the central axis C is formed on the other side. 3A, an annular gasket 27 surrounding the central axis C is disposed between the groove 23 and the protrusion 25, and the gasket 27 is sandwiched between the bottom surface of the groove 23 and the protrusion 25 in the axial direction. It is.

  One pipe (the pipe 5 in this example) of the first and second pipes 5 and 7 is attached to the heavy object 9. In the example of FIG. 2, the heavy object 9 is a heat retaining stand that covers the reactor pressure vessel 3 from above. That is, in FIG. 2, the reactor pressure vessel 3 is disposed in the containment vessel 29, and the heat retaining stand 9 that can open and close the opening 29 a at the top of the containment vessel 29 is provided at the top of the containment vessel 29. Yes. A heat insulating material for holding heat in the storage container 29 is incorporated in the heat insulating rack 9.

  The guide member 11 is integrally coupled to the heavy object 9. A pin 15 is also inserted into each insertion hole 11 a of the guide member 11. In the example of FIG. 3, the plurality of pins 15 respectively penetrate the plurality of insertion holes 11a with a slight gap. Accordingly, the pin 15 (that is, the flange 5a) is movable in the axial direction with respect to the guide member 11 (that is, the heavy object 9), but the pin 15 and the guide member 11 are directed in directions other than the axial direction. Are restricted from moving relative to each other.

The pipe support 13 is installed on the heavy object 9 and fixes one pipe 5 in the axial direction. 4 is a view taken in the direction of arrows IV-IV in FIG. 2B and shows the vicinity of the pipe support 13. In the example of FIG. 4, the pipe support 13 prevents one pipe 5 from moving in the axial direction with respect to the pipe support 13 by sandwiching one pipe 5 in the axial direction. In FIG. 4, the pipe support 13 includes a U-shaped member 13 a, a flat plate member 13 b through which each linear portion 14 of the U-shaped member 13 a passes, and a nut 13 c that is screwed into each linear portion 14. By rotating the nut 13c, one pipe 5 is sandwiched between the U-shaped member 13a and the flat plate member 13b.
The pipe support 13 can be displaced in the axial direction with respect to the heavy object 9 together with the one pipe 5 by an appropriate driving means. In the example of FIG. 4, the driving means is the cylinder device 16, and the cylinder device 16 displaces the pipe support 13 on one pipe by displacing the support 18 on which the pipe support 13 is installed in the axial direction. 5 and the heavy object 9 can be displaced in the axial direction.

  According to the pipe connection part structure 10 described above, when the pipes 5 and 7 are separated or connected, one pipe 5 is guided while the one pipe 5 is guided in the axial direction by fitting the pin 15 and the guide hole 17. Since it is separated or close to the other pipe 7, at this time, the first and second pipes 5, 7 are prevented from being displaced from each other in the direction orthogonal to the axial direction. This prevents the flanges 5a and 7a (particularly the protrusion 25 and the connection surface 21) from being rubbed and damaged.

(Piping connection separation method)
Next, a pipe separation and connection method using the above-described pipe connection portion structure 10 will be described. FIG. 5 is a flowchart showing this pipe separation and connection method.

  In step S1, when the first and second pipes 5 and 7 (flanges 5a and 7a) are connected to each other, the position of one pipe 5 is changed to the first and second positions at the connection portion of the pipes 5 and 7. The heavy article 9 is marked with respect to the axial direction of the pipes 5 and 7 (hereinafter simply referred to as the axial direction). For example, in FIG. 4, a mark M indicating the axial position of the reference point P on the pipe 5 side is attached to the structural member 22 fixed to the heavy article 9. In FIG. 4, the reference point P is a position on the support 18 on which the pipe support 13 is installed. Here, the pipe support 13 is in a state where the pipe 5 is fixed by sandwiching one pipe 5 between the U-shaped member 13a and the flat plate member 13b.

In step S2, one pipe 5 is moved so as to be disconnected from the reactor pressure vessel 3 which is the main device. Specifically, in step S 2, one pipe 5 is moved away from the other pipe 7 while being guided in the axial direction by fitting the pin 15 and the guide hole 17. Is disconnected from the reactor pressure vessel 3. In step S <b> 2, one pipe 5 is separated from the other pipe 7 until the flange 5 a and the flange 7 a are not rubbed with each other when they are displaced in a direction perpendicular to the axial direction with respect to each other. For example, one pipe 5 is separated from the other pipe 7 until the state shown in FIG. In this separation, one pipe 5 moves in the axial direction with respect to the other pipe 7 and the heavy object 9 that are stationary. This moving distance is a distance longer than the axial dimension of the concavities and convexities of the connection surfaces 19 and 21 (for example, the axial dimension of the protrusion 25).
In step S2, one of the pipes 5 is moved with respect to the heavy object 9, so that the flanges 5a and 7a are in a direction perpendicular to the axial direction by a slight gap between the pin 15 and the guide hole 17. Even if it deviates, the force which the connection surfaces 19 and 21 of the flanges 5a and 7a rub against each other can be suppressed. That is, it is possible to prevent the weight 9 from being added to the force.

  In step S <b> 2, the pipe support 13 installed on the heavy article 9 is moved in the axial direction, so that the pipe 5 is moved with respect to the heavy article 9. That is, in step S2, by keeping the pipe 5 fixed to the pipe support 13, the pipe support 13 is movable in the axial direction with respect to the heavy object 9 (for example, the cylinder device 16 can be expanded and contracted in the axial direction). The piping 5 is moved with respect to the heavy load 9.

  In step S3, one pipe 5 is fixed to the heavy object 9 in the axial direction. For example, the above-described piping support 13 (support 18) sandwiching one piping 5 in the axial direction between the U-shaped member 13a and the flat plate member 13b is fixed to the heavy object 9 (FIG. 4). The first pipe 5 is fixed to the heavy object 9 in the axial direction by connecting means such as welding or a clamp.

  In step S <b> 4, the first pipe 5 is completely separated from the second pipe 7 by moving one pipe 5 together with the heavy load 9. Next, in step S4, one pipe 5 is moved together with the heavy object 9 to a place different from the place where the reactor pressure vessel 3 is installed (reactor well 8 in the example of FIG. 2). Preferably, the another place is a place where the radiation dose is low to such an extent that the human body is not affected. Preferably, the other place is a place where the pipe 5 can be easily replaced, repaired or modified. In this way, one pipe 5 and the heavy object 9 are moved together to the other place.

  In step S5, one of the pipes 5 is replaced, repaired or modified at the other place.

  In step S5, when one of the pipes 5 is replaced with a new pipe (for example, a pipe having the same size and shape), a new pipe 5 is set in accordance with the position of the mark M attached to the heavy article 9 in step S1 in the axial direction. The pipe 5 is newly installed on the heavy object 9. In the example of FIG. 4, the pipe support 13 can be moved in the axial direction with respect to the heavy object 9 by releasing the coupling by the coupling means, and the new pipe 5 is sandwiched between the U-shaped member 13 a and the flat plate member 13 b. The new pipe 5 is fixed to the pipe support 13 and the axial position of the pipe support 13 (support 18) is adjusted so that the reference point P of the support 18 on which the pipe support 13 is installed and the mark of the heavy object 9 Let M coincide with the axial direction. As a result, a new pipe 5 is newly installed on the heavy object 9 in accordance with the position of the mark M.

  In step S5, when one pipe 5 is repaired or modified, the repair or modification is performed in a state where the one pipe 5 is positioned on the heavy object 9 at a position corresponding to the mark M. In the example of FIG. 4, the pipe support 13 is released by sandwiching the pipe 5 between the U-shaped member 13 a and the flat plate member 13 b so as to release the coupling by the coupling means in a state where the pipe 5 is fixed to the pipe support 13. Is freely movable in the axial direction with respect to the heavy load 9 and the axial position of the pipe support 13 (support 18) is adjusted, so that the reference point P of the support 18 on which the pipe support 13 is installed and the weight 9 The mark M is aligned with the axial direction, and in this state, the pipe 5 is repaired or modified.

  In step S5, the pipe 5 is exchanged, repaired, or modified in accordance with the mark M, which is a mark of the state in which the pipe 5 is connected to the main device 3. Therefore, in step S6 described later, It is possible to save the trouble of adjusting the length and the like.

  In step S6, one of the pipes 5 that has been replaced, repaired or modified is moved together with the heavy object 9 to the installation location of the reactor pressure vessel 3, and the pipes 5 and 7 (that is, the flanges 5a and 7a) are connected to each other. Then, the pipe 5 is connected to the reactor pressure vessel 3 again. This connection is made by inserting the pin 15 of the flange 5a of one of the pipes 5 after replacement, repair or modification into the guide hole 17 of the flange 7a. By connecting the pipes 5 and 7 in this way, the pipe 5 is connected again to the reactor pressure vessel 3 through the pipe 7.

  In step S6, preferably, the heavy article 9 is installed at the original position of the heavy article 9 at the time of step S1, and then the pipe 5 is moved in the axial direction with respect to the heavy article 9, The pipes 5 and 7 are connected to each other by inserting the pin 15 of the flange 5a into the guide hole 17 of the flange 7a.

  As shown in FIGS. 2A and 2B, another pipe 12 may be connected to the end of one pipe 5 opposite to the flange 5a. In this case, another pipe 12 may be separated from one pipe 5 before step S2. For example, before step S <b> 2, the pipe 5 is disconnected from the other pipe 12 at the connection position P (see FIGS. 2A and 2B) between the pipe 5 and the other pipe 12, thereby the pipe 5. Is separated from another pipe 12, and in step S6, the end of the pipe 5 opposite to the flange 5a is reconnected to the separated another pipe 12 by welding or the like. In addition, the piping 5 and the piping 12 may be integrally formed so that one piping may be comprised, for example.

  Further, the flanges 5a and 7a are connected to each other by an appropriate connection maintaining means (for example, a bolt and a nut) to maintain the connection between the flanges 5a and 7a, and by releasing the connection by the connection maintaining means, the flange 5a and 7a can be separated from each other. Accordingly, step S2 is performed in a state where the coupling between the flanges 5a and 7a by the coupling maintaining means is released. In step S6, the flanges 5a and 7a connected to each other are coupled by the coupling maintaining means and this state is obtained. maintain.

  According to the pipe separation and connection method described above, the pipe 5 is moved together with the heavy object 9 to a place (for example, a floor) different from the inside of the reactor well 8 where the reactor pressure vessel 3 is arranged. Replace, repair, or modify pipe 5 at the location. Therefore, replacement, repair, or modification of the pipe 5 and other work related to the reactor pressure vessel 3 (for example, repair work of the reactor well 8) can be performed efficiently at the same time. Therefore, the repair work in the reactor well 8 can be completed at an early stage, and the operation of the reactor can be resumed at an early stage.

  The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention. For example, you may employ | adopt the following modifications 1-6 in combination or independently. In this case, points not described below may be the same as described above, or may be changed as appropriate.

(Modification 1)
In the above description, the heavy object 9 is the heat retaining frame of the storage container 29, but may be other things.

(Modification 2)
You may perform above-mentioned step S2 in the state which fixed one piping 5 to the heavy article 9. FIG. That is, in this state, one pipe 5 and the heavy object 9 may be separated from the other pipe 7 while being guided in the axial direction by fitting the pin 15 and the guide hole 17 together. In this case, step S3 is omitted, and step S2 and step S4 are performed simultaneously.
Similarly, step S6 described above may be performed in a state where one pipe 5 is fixed to the heavy object 9. That is, one pipe 5 and the heavy object 9 fixed to each other are integrally moved while being guided in the axial direction by fitting the pin 15 and the guide hole 17 so that one pipe 5 is moved to the other pipe 7. You may connect to.

(Modification 3)
According to the present invention, the pipe connection part structure 10 described above may not be used for the pipe separation connection method described above. That is, the pipe connection part structure 10 of the present invention is a structure that is used when the flanges 5a and 7a can be prevented from being damaged by rubbing the flanges 5a and 7a when the pipes 5 and 7 are separated or connected. You just have to.

(Modification 4)
In the above description, the pipe 5 is connected to the reactor pressure vessel 3 that is the main device, but according to the pipe separation and connection method of the present invention, the main device is not limited to the reactor pressure vessel 3. That is, the main device may be a device (for example, a container) that uses or accumulates fluid other than the reactor pressure vessel 3. In this case, the main device may not be a device in the nuclear power plant, and the heavy article 9 may be composed of, for example, a pipe support that supports the pipe 5 and a structure that supports the pipe support. .

(Modification 5)
According to the pipe separation and connection method of the present invention, the pipe is disconnected from the main body device, and then the pipe is moved together with the heavy object to a place different from the place where the main body equipment is arranged. If the pipe can be used to reconnect the main equipment by moving, replacing, repairing or remodeling the pipe and moving the pipe that has been replaced, repaired or remodeled with a heavy object, the above-described embodiment It is not necessary to use the pipe connection part structure 10 by. For example, in the pipe separation and connection method of the present invention, the pipe connected to the main unit without using the flanges such as the flanges 5a and 7a described above (for example, by cutting the end of the pipe on the main unit side). It may be a method of separating from the main device and connecting again to the main device (for example, by welding to a pipe portion extending from the main device side).

(Modification 6)
In the above description, one pipe 5 is connected to the other pipe 7 extending from the main device (reactor pressure vessel) 3 with the flanges 5a and 7a as connection portions. It may be connected to another piping 12 extended from main part equipment (reactor pressure vessel) 3 like this. 6 (B) is a partially enlarged view of FIG. 6 (A), and FIG. 6 (C) is a cross-sectional view taken along the line CC in FIG. 6 (B). In the case of FIG. 6, a flange 5 a is provided at the end of one pipe 5 opposite to the other pipe 12, and this flange 5 a is connected to the flange 7 a of the pipe 7. The structure and operation of the flanges 5a and 7a are the same as described above. In this case, in step S2, the pipe 5 is cut from the other pipe 12 at the connection position P between the pipe 5 and the other pipe 12 (see FIGS. 6A and 6B), and then one pipe. 5 from the other pipe 7 while guiding the pin 15 and the guide hole 17 in the axial direction (that is, the axial direction of the first and second pipes 5 and 7 at the connecting portion of the pipes 5 and 7). One pipe 5 is separated from the reactor pressure vessel 3 by being moved so as to be separated. In step S6, the pipe 5 is connected again to the separated pipe 12 by welding or the like. In FIG. 6A, the pipe 5 and the pipe 12 may be integrally formed so as to constitute one pipe, for example.

3 reactor pressure vessel, 5 first piping, 5a flange, 7 2nd piping, 7a flange, 8 reactor well, 9 heavy load (insulation rack), 10 piping connection structure, 11 guide member, 11a insertion hole , 13 Piping support, 13a U-shaped member, 13b Flat plate member, 13c Nut, 14 Linear portion, 15 Pin, 16 Cylinder device, 17 Guide hole, 18 Support, 19 Connection surface, 21 Connection surface, 22 Structural member, 23 Groove, 25 protrusion, 27 gasket, 29 containment vessel

Claims (6)

A pipe separation and connection method that is connected to a main body device and that separates a pipe attached to a heavy object from the main body device and connects the pipe to the main body device again.
(A) Move the piping so as to be disconnected from the main device,
(B) Next, the piping is moved together with the heavy object to a location different from the installation location of the main device,
(C) Replace, repair or modify the piping at the other location,
(D) A pipe separation and connection method, wherein the pipe that has been replaced, repaired or modified is moved together with the heavy object to the installation location of the main device, and the pipe is reconnected to the main device. The pipe is one of the first and second pipes connected to each other;
The first and second pipes are provided with flanges serving as connection portions therebetween, and the flanges of the first pipes extend in the axial direction of the first and second pipes at the connection portions. A plurality of pins are provided, a plurality of guide holes extending in the axial direction are formed in the flange of the second pipe, and the plurality of pins are inserted into the plurality of guide holes The flanges of the first and second pipes are butted together and connected,
The movement of the one pipe in (A) is performed while being guided in the axial direction by the fitting of the pin and the guide hole, whereby the one pipe is connected to the first and second pipes. The pipe separation and connection method according to claim 1, wherein the pipe is separated from the other pipe. In (A), the one pipe is moved away from the other pipe by moving the one pipe relative to the other pipe and the heavy object,
3. The pipe separation and connection method according to claim 2, wherein (B) is performed in a state where the one pipe is fixed to the heavy object.   4. The method according to claim 1, wherein the main body device is a reactor pressure vessel, and the heavy object is a heat retaining stand that covers the reactor pressure vessel from above. .   The pipe separating and connecting method according to claim 3, wherein a mark indicating the position of the one pipe with respect to the axial direction is attached to the heavy object before (A). A pipe connection part structure constituting a connection part of the first and second pipes,
The first and second pipes are provided with flanges serving as connection portions therebetween, and the flanges of the first pipes extend in the axial direction of the first and second pipes at the connection portions. A plurality of pins are provided, a plurality of guide holes extending in the axial direction are formed in the flange of the second pipe, and the plurality of pins are respectively inserted into the plurality of guide holes. A pipe connection part structure characterized in that flanges of the first and second pipes are butted together in a state.