JP2012112893A - Pipe support, attachment fixture of pipe support and attachment method of pipe support - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe support allowed to be easily attached to an existing control rod driving pipe in a narrow space and capable of achieving seismic reinforcement.SOLUTION: A pipe support 10 of a pair of second pipes 14 extended from a flange 16 of a first pipe 12 so as to hold the first pipe 12 with a gap 15 along the longitudinal direction of the first pipe 12 includes a curved part 22 for holding the first pipe 12 along the outer periphery of the first pipe 12 and a pair of clamps 20 of which the both ends are projected from the flange 16 in a plan view. The clamps 20 are provided with a pair of first support pieces 30 for supporting between the first pipe 12 and the second pipes 14 and a pair of second support pieces 40 having a rectangular cross section to support the second pipes 14 so as to hold them opposite to the first support pieces 30. The first support piece 30 is shorter than the second support piece 40, and the second support piece 40 is set shorter than the interval of the pair of clamps 20 in a fixed state to the first pipe 12.

Description

  The present invention relates to a pipe support that supports a control rod drive pipe of a nuclear power plant, a pipe support fixture, and a pipe support attachment method.

  6A and 6B are explanatory views of a conventional housing and control rod drive piping. FIG. 6A is a side view, FIG. 6B is an enlarged perspective view of a flange portion of the housing, and FIG. 6C is a plan view of the housing. is there.

  A housing 120 for a control rod drive mechanism (hereinafter simply referred to as CRD (control rod drive)) for forming and removing control rods for output control in the vessel is formed below the pressure vessel in the nuclear power plant. A flange 160 is formed at the lower end of the housing 120 extending from the lower part of the pressure vessel to the reactor containment vessel. A large number of housings 120 are attached to the lower surface of the pressure vessel with a predetermined interval, and the gap between adjacent flanges is small as shown in FIG.

  In a nuclear power plant, a large number of piping groups connect the water pressure control unit in the reactor building to the engagement of the flange 160 of the housing 120 of the reactor containment vessel. A CRD pipe 140 is connected to the flange 160. The CRD pipe 140 is a pipe that connects the CRD and an external water pressure control unit, and includes an insertion pipe and a drawing pipe. As shown in (B), the CRD pipe 140 extends from the flange 160 of the housing 120 along the longitudinal direction of the housing 120 so as to sandwich the housing 120 with a predetermined gap from the housing 120. Patent Document 1 is disclosed as a method for installing such a pipe group.

JP-A-7-12777

  Regarding the existing CRD piping installed in a conventional housing, the inventors of the present application verified the structural analysis assuming the vibration at the time of the occurrence of an earthquake. As a result, stress is likely to be concentrated at the connection point between the CRD piping and the housing flange. found. In particular, as shown in (B), stress tends to concentrate on vibrations on a straight line (X-axis direction) passing through the axis of the pair of CRD pipes.

  In addition, since the flange portion of the housing where the CRD pipe is installed is located above the inspection work table, the operator cannot see the upper surface side of the flange, that is, the location where the CRD pipe is connected, and the lower surface of the flange. I can only see the side. Therefore, when trying to attach the support for CRD piping to the existing equipment to prevent the above-mentioned vibration, the place to be attached is a narrow place where the gap between adjacent housings is small and very difficult work. Become. In addition, the U-shaped tube generally used for supporting pipes has a problem that not only the insertion from the gap is difficult at the time of mounting, but also the adjacent housing interferes and the mounting is difficult.

  Therefore, in order to solve the above-described problems of the prior art, the present invention provides a pipe support that can be easily attached to an existing CRD pipe and can be seismically reinforced in a narrow place, a pipe support fixture, and a pipe It aims at providing the attachment method of a support tool.

In order to solve the above-described problems of the prior art, the pipe support of the present invention includes a pair of pipes extended from the flange of the first pipe so as to be sandwiched with a gap along the longitudinal direction of the first pipe. A pipe support for a second pipe, comprising a pair of clamps having a curved portion sandwiched along an outer periphery of the first pipe and having both ends projecting from the flange in plan view; Is a pair of first support pieces that support between the first and second pipes, and a pair of rectangular sections that support the first pipes so as to sandwich the second pipes while facing the first support pieces. A second support piece, wherein the first support piece is shorter than the second support piece, and the second support piece is attached to the first pipe. It is characterized by being set shorter than the interval between the clamps.
In this case, the clamp may be attached with a leg protruding from the end portion toward the attachment surface of the flange.

  The second support piece includes a through hole of a fastening means for fixing the pair of clamps, and the clamp has a bolt head and a nut in plan view when attached to the first pipe. It is good to set to the length dimension which protrudes rather than the outer periphery of the said flange.

  The pipe support fixture according to the present invention has a pipe support for a pair of second pipes that are extended from the flange of the first pipe so as to have a gap along the longitudinal direction of the first pipe. A tool mounting jig, a plate main body, a recess formed on the abutting portion of the plate main body and abutting toward an axis of one of the second pipes, and the pipe support tool A groove into which the second support piece can be inserted, an adjustment bolt that is screwed in a direction orthogonal to the plate surface of the plate body, and abuts against the second pipe to adjust the vertical direction of the plate surface; It is characterized by having.

  The pipe support attachment method of the present invention includes a pipe support for a pair of second pipes that are extended from a flange of the first pipe so that a gap is formed along the longitudinal direction of the first pipe. In this method, the concave portion of the pipe support fixture is brought into contact with one of the second pipes, and the second support piece of the pipe support is attached to the pipe support tool. Is inserted into the groove of the mounting jig, the first pipe is clamped by the other clamp from the side facing the one clamp, and the clamp is fastened and fixed.

  According to the pipe support, the pipe support fixture, and the pipe support attachment method of the present invention, the pipe support can be easily attached even in a narrow place and an existing CRD pipe. The second pipe can suppress vibrations and be seismically reinforced with the first pipe as a supporting base.

  Moreover, a pipe support can be attached and set by groping in a narrow part where the attachment target part cannot be directly visually observed.

It is a perspective view of the piping support tool of this invention. It is a figure which shows the structure outline of the piping support tool of this invention. It is a figure which shows the structure outline of the attachment jig | tool of the piping support tool of this invention. It is explanatory drawing of the attachment jig | tool of a piping support tool. It is explanatory drawing which shows the attachment method of the piping support tool of this invention. It is explanatory drawing of the conventional housing and control rod drive piping.

A pipe support, a pipe support fixture, and a pipe support attachment method of the present invention will be described in detail below with reference to the accompanying drawings.
The piping support of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a pipe support of the present invention. FIG. 2 is a diagram showing a schematic configuration of the pipe support of the present invention, (A) shows a plan view disassembled for each component part, (B) shows a plan view in which each component part is assembled, (C ) Shows a front view of the clamp.

  The first and second pipes 12 and 14 to which the pipe support 10 of the present invention is attached include a first pipe 12 having a diameter larger than that of the second pipe 14 and a first pipe 12 as illustrated. It is comprised from a pair of 2nd piping 14a, 14b so that it may be pinched | interposed from both sides centering on this. A flange 16 is formed on the first pipe 12 extending in the vertical direction. A pair of second pipes 14 a and 14 b extend from the flange 16 along the axis of the first pipe 12 with a predetermined interval 15. In addition, each axial center of the 1st and 2nd piping 12 and 14 is arrange | positioned on the same plane (XZ surface in FIG. 1). In the present embodiment, the first pipe 12 is a CRD housing, and the second pipe 14 is a CRD pipe.

The piping support 10 of the present invention has a clamp 20, first and second support pieces 30, 40, fastening means 50, and legs 60 as the main basic configuration.
The clamp 20 (20a, 20b) is on a straight line passing through the longitudinal direction of the first and second pipes 12, 14 (Z-axis direction in FIG. 1) and the axis of each of the first and second pipes 12, 14. These are a pair of rectangular fittings that sandwich the first and second pipes 12 and 14 from the direction intersecting (the X-axis direction of FIG. 1), that is, the Y-axis direction of FIG. In the vicinity of the center of the clamp 20, a curved portion 22 that can be bent along the outer periphery of the first pipe 12 and sandwich the first pipe 12 is formed. Both ends of the curved portion 22 form a flat portion 23 that extends in the X-axis direction. In either one of the pair of clamps 20a and 20b, the first and second support pieces 30 and 40 are formed on the plane portion 23. In this embodiment, the clamp 20a is formed. The length of the clamp 20 is set such that the end 24 protrudes outward from the flange 16 in plan view when the curved portion 22 is brought into contact with the first pipe 12. Specifically, the length of the clamp 20 is a plan view corresponding to a diagonal distance (L in FIG. 2A) of a bolt head or a nut 54 of a fastening bolt 52 to be described later in a state where the clamp 20 is attached to the first pipe 12. Thus, it is set so as to protrude outward from the flange 16.

  The first support piece 30 is a plate-like member that can be inserted into the gap 15 between the first and second pipes 12 and 14, and the thickness of the member is larger than the gap 15 between the first and second pipes 12 and 14. Is slightly thinner. The first support piece 30 extends in a direction orthogonal to the longitudinal direction of the clamp 20a toward the opposing clamp 20b. The first support piece 30 has a chamfered portion 32 formed on the outer side, that is, at the tip on the second support piece 40 side. Accordingly, when the first support piece 30 is inserted into the gap 15 between the first and second pipes 12 and 14 from the direction orthogonal to the straight line passing through the axis of the pair of second pipes 14, the insertion is easy. In addition, there is no possibility that the first support piece 30 contacts the second pipe 14 and damages the pipe. A support 34 is formed at a connection portion between the first support piece 30 and the flat portion 23. The support 34 is formed with a thick connection portion between the first support piece 30 and the flat portion 23, and has a tapered shape that tapers toward the tip of the first support piece 30. With such a configuration, the connection location (the base portion of the first support piece 30) can be reinforced without contacting the second pipe 14. The first support piece 30 is set shorter than the second support piece 40 described later.

  The second support piece 40 is a pair of support members that face the first support piece 30 and sandwich the first support piece 30 side from the outside of the second pipe 14. The second support piece 40 is formed on the flat surface portion 23 on the outer side (the end portion 24 side) than the first support piece 30. The second support piece 40 is formed in a rectangular cross section. The second support piece 40 has a through hole 42 into which a fastening bolt 52 of a fastening means 50 described later is inserted in the longitudinal direction. In the pair of clamps 20a and 20b, an opening 26 is formed at a location where the second support piece 40 comes into contact. The length of the second support piece 40 is set to be shorter than the interval in the state where the clamp 20 is attached to the first pipe 12. For this reason, the entire pipe support 10 can be fastened to the first pipe 12 by a spring action in which the opposing flat portion 23 is pressed against the pipe side when tightened by the fastening means 50 described later.

  The second support piece 40 is formed to have a rectangular cross-sectional shape. Thereby, the contact area of the tangential direction of the 1st and 2nd piping 12, 14 of circular cross section increases, and it can fix stably.

  The fastening means 50 includes a fastening bolt 52 and a nut 54. The fastening bolt 52 is set longer than the second support piece 40. The fastening bolt 52 is inserted into the through hole 42 of the second support piece 40 and is screwed into the nut 54 to be fastened.

  As described above, the length of the clamp 20 is the same as that of the bolt head of the fastening bolt 52 or the diagonal distance of the nut 54 (L in FIG. 2A) in the state of being attached to the first pipe 12. Thus, it is set so as to protrude outward from the flange 16. For this reason, when the fastening bolt 52 is inserted into the through hole 42 of the second support piece 40 and the clamp 20 is fastened, both ends of the fastening means 50 protrude outward from the flange 16 in plan view. Become. Thereby, when tightening the pipe support 10 from the lower surface side of the flange 16, a tool such as a ratchet can be fitted.

  A plurality of legs 60 are formed on the curved portion 22 of the clamp 20. The leg 60 is a direction that intersects the longitudinal direction of the clamp 20, one end is fixed to the side surface of the clamp 20, and the other end is formed to protrude from the clamp 20 toward the flange 16. The length of the leg 60 protruded from the clamp 20 is such that the flange bolt or nut (not shown) formed on the surface of the flange 16 of the first pipe 12 does not contact the clamp 20 with the flange 16. The length is set so that there is a gap. When the clamp 20 is attached to the first pipe 12, the legs 60 are formed in the curved portion 22 by being radially distributed from the axis C of the first pipe 12 as shown in FIG. . Further, the legs 60 are provided at predetermined intervals so as to avoid the fastening portions (not shown) such as bolts or nuts on the flange 16 of the first pipe 12 so as to contact the surface of the flange 16. Thereby, the clamp 20 can be stably temporarily placed on or fixed to the flange 16 without being interfered by an obstacle on the upper surface of the flange 16.

  The clamp 20, the first and second support pieces 30, 40, the legs 60, and the fastening means 50 constituting the pipe support 10 are made of the same material as the second pipe 14 in order to prevent electrolytic corrosion. It is desirable to use stainless steel as an example.

Next, an attachment jig for attaching the pipe support 10 having the above configuration to the first and second pipes 12 and 14 will be described below.
FIG. 3 is a diagram showing a schematic configuration of a mounting jig for a pipe support according to the present invention, (A) shows a plan view (excluding vertical position adjusting means), and (B) is a front view (excluding adjusting bolts). (C) shows a side view. FIG. 4 is an explanatory view of a pipe support fixture. The pipe support attachment jig 70 of the present invention includes a plate main body 72, a contact portion 74, a concave portion 76, a convex portion 78, a groove 80, a handle 82, and a vertical position adjusting means 84. Basic structure.

  The plate body 72 is a substantially rectangular flat plate. In the plate main body 72 of the present embodiment, the length of the flat plate is set to be equal to or longer than the sum of the height of the clamp 20 of the pipe support 10 and the length of the leg 60 protruding from the clamp 20. The plate body 72 has an abutting portion 74, a concave portion 76, a convex portion 78, and a groove 80 formed at one end (upper portion), a vertical position adjusting means 84 formed near the center, and the other end portion (lower portion). The handle 82 is formed.

  The contact portion 74 extends from the plate surface of the plate main body 72 in a direction perpendicular to the plate surface. The abutting portion 74 has a concave portion 76 formed at the tip portion extending from the plate body 72 and a convex portion 78 formed on the lower surface. Note that the length of the contact portion 74 is longer than the thickness of the second support piece 40.

  As shown in FIG. 3A, the recess 76 is formed in a semicircular shape along the outer periphery of the second pipe 14 so that it can come into contact with the outer periphery from the cross-sectional direction of the second pipe 14. . Thereby, the contact part 74 which contact | abutted toward the axial center of any one said 2nd piping 14 from the straight line passing through the axial center of said pair of 2nd piping 14 is temporarily fixed. it can.

  The convex portion 78 extends downward from the contact portion 74 so as to be parallel to the plate body 72. As shown in FIG. 3A, the convex portion 78 is formed so that the side surface on the plate body 72 side substantially coincides with the apex S (the deepest portion of the notch) of the concave portion 76. A pair of convex portions 78 of this embodiment are formed on both sides of the deepest portion of the concave portion 76.

As shown in FIG. 3C, the groove 80 is formed between the plate body 72 and the convex portion 78 when the plate body 72 is viewed from the side. The width of the groove 80 is formed so as to substantially match the thickness of the second support piece 40. Thereby, the 2nd support piece 40 of the piping support tool 10 can be inserted from the direction (Y-axis direction of FIG. 1) orthogonal to the straight line which passes along the axial center of a pair of 2nd piping 14. As shown in FIG.
In addition, the plate main body 72, the contact part 74, and the convex part 78 each chamfered the end surface.

  The handle 82 has an upper end connected to the lower portion of the plate body 72 so as to extend downward from the plate body 72. In this embodiment, the upper end of the handle 82 is threaded. Further, a long nut 83 screwed with the tip of the threaded handle 82 is fixed to the lower end of the plate body 72 by welding so that the longitudinal direction is parallel to the longitudinal direction of the plate body 72. The handle 82 can be attached to the plate body 72 by screwing the threaded portion at the tip of the handle 82 into the long nut 83. The handle 82 may be configured such that the length can be arbitrarily changed by a slide mechanism, a joint mechanism, or the like.

  The vertical position adjusting means 84 is configured such that an axial center of a through hole 85 formed in the vicinity of the center of the plate body 72 is attached so that the hole center of the nut 86 coincides, and an adjusting bolt 88 is inserted into the nut 86. The length of the adjustment bolt 88 is set longer than the thickness of the second support piece 40. It is possible to prevent the adjustment bolt 88 from dropping from the plate body 72 by screwing the adjustment bolt 88 into the nut and then crushing the threaded end of the bolt.

The pipe support attachment jig 70 of this embodiment is arranged so that the center of the recess 76, the axis of the adjustment bolt 88 of the vertical position adjusting means 84, and the axis of the handle 82 are located on the same plane. ing.
In addition, the plate main body 72, the contact part 74, the recessed part 76, the convex part 78, the groove | channel 80, the handle 82, and the vertical position adjustment means 84 which comprise the attachment jig 70 of a piping support tool are stainless steel as an example. Can be used.

Next, a method for mounting the pipe support of the present invention using the pipe support mounting jig having the above configuration will be described below.
FIG. 5 is an explanatory view showing a method for attaching the pipe support of the present invention. As described above, the plurality of housings serving as the first pipes 12 are densely formed with a predetermined gap below the pressure vessel. In order to attach the pipe support 10 to this housing, it is carried out from an inspection work table installed below the housing. At this time, the upper surface of the flange surface of the housing cannot be seen from below, and is attached by groping. Therefore, first, a pipe support attachment jig 70 is inserted into the gap between the upper first pipes 12 from a position where the lower end of the pipe group of the first pipes 12 is looked up. And the recessed part 76 of the contact part 74 provided in the upper end of the plate main body 72 is contact | abutted toward the axial center of any one 2nd piping 14 from the straight line which connects the axial center of the 2nd piping 14 (FIG. (I) in 5). At this time, a part of the end surface of the abutting portion 74 extending in the horizontal direction from the plate body 72 is cut out to form the concave portion 76, so that the second pipe 14 and the concave portion 76 are fitted to each other to be fixed. can do. Note that the contact position of the second pipe that contacts the recess 76 is desirably a position higher than the length corresponding to at least the end (upper end) of the clamp 20 and the tip (lower end) of the leg from the upper surface of the flange 16. .

  The vertical position adjustment is performed with the second pipe 14 in contact with the recess 76. Specifically, when the lower end of the plate body 72 is inclined outward from the axis of the first pipe 12 with respect to the upper end by the adjustment bolt 88 of the vertical position adjusting means 84, the adjustment bolt 88 is loosened to loosen the plate. The lower end of the plate main body 72 is inclined inward so that the main body 72 coincides with the vertical direction (the direction parallel to the axis of the CRD pipe). When the lower end of the plate main body 72 is inclined inward from the axis of the first pipe 12 with respect to the upper end, the plate main body 72 is adjusted so that the plate main body 72 coincides with the vertical direction by tightening the adjustment bolt 88. Tilt the lower end of to the outside. Thereby, the groove | channel 80 which inserts the 2nd support piece 40 can be ensured, and the 2nd support piece 40 can be inserted in the groove | channel 80 easily. Note that the amount of protrusion of the adjustment bolt 88 may be adjusted in advance according to the thickness of the second support piece 40.

  Next, among the pair of clamps 20a and 20b, the clamp 20a in which the first and second support pieces 30 and 40 are formed is inserted from the gap between the flanges 16 of the first pipe 12, and one of the first clamps 20a and 20b is inserted. The two support pieces 40 are inserted into the groove 80 from a direction orthogonal to a straight line passing through the axis of the pair of second pipes 14 ((ii) in FIG. 5). At this time, since the first support piece 30 is formed shorter than the second support piece 40, the clamp 20 in which the second support piece 40 is arranged substantially parallel to the surface of the flange 16 is inserted into the groove 80. When starting, the first support piece 30 does not come into contact with the first pipe 12. Therefore, since it is possible to work in a place close to the plane passing through the axis of the first and second pipes 12 and 14, that is, by reducing the lateral space, a large number of pipes are arranged in a narrow space. When installing the pipe support, the installation work is simplified.

  Further, since the distance between the first and second support pieces 30 and 40 is set to a length that allows the second pipe 14 to be inserted, the second support piece 40 can be formed in the groove 80 even in groping. By inserting, the 1st support piece 30 can be inserted in the clearance gap between the 1st and 2nd piping 12,14.

  After the second support piece 40 is inserted and the curved portion 22 of one clamp 20a is brought into contact with the outer periphery of the first pipe 12, the other clamp 20b is inserted from the side facing the one clamp 20a. Then, the tip of the second support piece 40 is aligned with the opening 26 ((iii) in FIG. 5).

After positioning the clamp 20, the fastening bolt 52 of the fastening means 50 is inserted into the through hole 42 of the second support piece 40, and the nut 54 is fitted to the tip of the bolt protruding from the other clamp 20 b side and temporarily tightened. To do. Then, after fine adjustment is performed so that the tip of the leg 60 of the clamp 20 comes into contact with the surface of the flange 16, the fastening means 50 is finally tightened. Thus, the first pipe 12 can be sandwiched between the curved portions 22 of the pair of clamps 20. Further, the first and second pipes 12 and 14 can be sandwiched by the first and second support pieces 30 and 40, and the vibration in the linear direction passing through the axis of the second pipe 14 can be prevented. .
After the clamp 20 is fastened and the pipe support 10 is attached, the pipe support attachment jig 70 is removed from the first and second pipes 12 and 14.

  According to the method for attaching the pipe support of the present invention, the pipe support can be easily attached even in a narrow place and an existing CRD pipe, and the second pipe is the first pipe. Vibration can be suppressed and seismic reinforcement can be performed as a support matrix. Moreover, a pipe support can be attached and set by groping in a narrow part where the attachment target part cannot be directly visually observed.

10 ......... Pipe support, 12 ......... First pipe, 14 ......... Second pipe, 15 ......... Gap, 16 ......... Flange, 20 ......... Clamp, 22 ......... Curve , 23... Plane portion, 24... End portion, 26... Opening, 30... First support piece, 32. Support piece 42... Through-hole 50... Fastening means 52... Fastening bolt 54... Nut 60... Leg 70. ......... Plate body, 74 ... ... Abutment part, 76 ... ... Recess, 78 ... ... Projection, 80 ... ... Groove, 82 ... ... Handle, 83 ... ... Long nut, 84 ... ... Vertical position adjusting means, 85 ......... through hole, 86 ......... nut, 88 ......... adjustment bolt, 120 ......... housing, 140 ......... CRD piping, 60 ......... flange.

Claims (5)

A pipe support for a pair of second pipes extended from a flange of the first pipe so as to sandwich a gap along the longitudinal direction of the first pipe,
A curved portion sandwiched along the outer periphery of the first pipe, and a pair of clamps having both ends projecting from the flange in plan view;
The clamp has a pair of first support pieces that support between the first and second pipes, and a rectangular cross section that supports the first pipes so as to face the first support pieces and sandwich the second pipes. A pair of second support pieces,
The first support piece is shorter than the second support piece, and the second support piece is set to be shorter than an interval between the pair of clamps in a state of being attached to the first pipe. Piping support characterized by being.   The piping support according to claim 1, wherein the clamp is provided with a leg protruding from an end portion toward the attachment surface of the flange. The second support piece includes a through hole of a fastening means for fixing the pair of clamps,
The clamp is set to have a length dimension such that a bolt head and a nut of the fastening means protrude from an outer periphery of the flange in a plan view when attached to the first pipe. The piping support according to 1 or 2. A mounting jig for a pipe support for a pair of second pipes extending from a flange of the first pipe so as to sandwich a gap along the longitudinal direction of the first pipe,
The plate body,
A recess formed on the abutting portion of the plate body and abutting toward the axis of one of the second pipes;
A groove into which the second support piece of the pipe support according to any one of claims 1 to 3 can be inserted;
An adjustment bolt that is screwed in a direction orthogonal to the plate surface of the plate body and abuts on the second pipe to adjust the vertical direction of the plate surface;
A jig for attaching a pipe support, comprising: A mounting method for a pipe support for a pair of second pipes extending from a flange of a first pipe so as to sandwich a gap along the longitudinal direction of the first pipe,
The concave portion of the pipe support fixture according to claim 4 is brought into contact with any one of the second pipes,
Inserting the second support piece of the pipe support according to any one of claims 1 to 3 into a groove of an attachment jig of the pipe support,
Sandwiching the first pipe with the other clamp from the side facing the one clamp,
A pipe support attaching method, wherein the clamp is fastened and fixed.

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