JPS5913184A - Device for stopping piping - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piping control device for high-temperature, high-pressure fluid piping in a nuclear couplant, and particularly to a piping restriction device suitable for use in a curved pipe section of a pressure tube type nuclear reactor having a tube group structure.

A piping restraint device for preventing piping whip when a high temperature, high pressure fluid piping such as a coolant piping in a conventional atomic couplant is ruptured is shown in FIGS. 1 to 4.

FIGS. 1 and 2 show a structure in which a U-shaped side stop bar 2 is provided around a pipe 1 with a gap in between, and when the pipe 1 breaks, the pipe 1 collides with the stop bar 2 and the stop An example of a pipe restraining device is shown in which the rod 2 is stretched plastically and absorbs energy to restrain the pipe 1.

In the examples shown in Figures 1 and 2, the target is a light water reactor with a small number of large diameters, which is effective as a restraint device because the permissible swing range of the broken pipe is relatively large, but in the pressure tube reactor shown in Figure 5, For the 11 pipe group 1, the pipe gaps are limited due to space constraints in the arrangement, so the
It is impossible to install a restraining device as shown in the figure.

In order to eliminate the above-mentioned drawbacks, it is necessary to install a restraining device on the target piping itself.

FIG. 3 shows an example of a device devised to satisfy the above conditions, in which the part of the target piping where the expected breakage is locally constructed is a double pipe structure, and the protrusion 9 is inserted through the entire hole 10 provided in the outer pipe 4. It has a structure in which it is fixed to the outer surface of the inner tube 3 by welding, and when the unborn object 9 fixed to the outer surface of the inner tube 3 comes into contact with the hole 10 provided in the outer tube 4, a thrust impact occurs when the inner tube breaks. It has a double tube structure that absorbs force.

In the structure shown in FIG. 3, if the expected breakage part of the target piping is the welded part 5 of the pipe joint, the welded part is covered by the outer pipe 4, so there is a drawback that it cannot be inspected during the service period after installation.

FIG. 4, like FIG. 3, is an example of a device in which the piping restraint device is attached to the target piping itself, where a pair of lugs 6 are fixed to the piping 1 by welding, and a rib 7 is attached to the lug 6 and the piping for further reinforcement. IK
A rod 8 is inserted into a rod through hole (not shown) provided in the lug 6 and welded to the lug 6. When the pipe ruptures and the internal fluid flows out, and the reaction force whips the target pipe l, the rod 8 prevents the whipping action of the pipe.

In the example of the device shown in Figure 4, it is possible to visually inspect the welded parts of the target piping after installation, which are likely to break, during the service period. It is necessary to weld 8 to the lug 6 on-site, and when the number of target pipes increases as the size of the nuclear reactor increases, there is a drawback that the number of man-hours increases. In order to reduce the number of work steps, it is possible to use a screw-in method for fixing the rod 8 to the lug 6, but according to this method, the strength of the threaded part structure against the whip load of the target piping 1 is is considered to reduce reliability.

In addition, in order to weld only the rod 8 and lug 6 on site, if the rib 7 and lug 6 are welded to the smooth piping 1, the welding part for attaching an automatic welding machine that welds the piping joint The surrounding space required limits reducing the distance between paired lugs. Regarding whip loads in the direction perpendicular to the pipe axis of the pipe 1 and torsional whip loads, the smaller the distance between the paired lugs, the more reliable the pipe restraint device will be. In order to improve the reliability of the pipe 1, the welding between the piping 1, the lug 6, and the rib 7 must be carried out after welding the pipe joints on-site, which has the drawback of increasing the number of on-site work. .

In addition, as shown in Figure 5, the inspection during the service period after installation of target piping group 1 located directly above and below reactor 1.1 will be performed under high radiation doses, so the work will be automated. There is a need to. The device example shown in FIG. 4 has the disadvantage that once the rod 8 is welded to the lug 6, it becomes impossible to install automatic equipment for inspection during the service period after installation.

In order to solve the above-mentioned drawbacks, the inventions shown in FIGS. 6, 7 and 8 were devised by the Development Department 456-131. In the present invention, a spacer is further provided between the pair of lugs, and the spacer and the rod fixed to the spacer have a structure that receives the whip load. In order to improve the reliability of piping restraint and equipment, the pair of lugs is divided into an outer ring and a lug fixed to the pipe, and a spacer is further provided between the pair of outer rings and the pair of lugs. By integrating it with a rod and making it removable from the lug fixed to the target piping, it is possible to minimize the number of on-site work required for installing this device, and also to facilitate inspections during the service period after installation. It is characterized by the ability to attach and detach automatic devices for the purpose.・□The present invention is suitable as a piping control device for a straight pipe section, but it is impossible to fully satisfy the above conditions for a curved pipe section. In order to apply the present invention to a bent pipe section, it is necessary to
The rod 8 cannot be fixed to the spacer j3, and unless the spacer 13 is fixed to the rod 8, the spacer 13 will be
It moves freely and cannot fully fulfill its role as a piping restraint device. In addition, the spacer 13 is connected to the target pipe I.
Once K is fixed, there is a further drawback that the restraining device cannot be removed.

The purpose of the present invention is to eliminate the drawbacks of the prior art, to minimize the number of on-site work required for installing this device, and to enable automatic installation and removal of the device for inspection during the service period. It is an object of the present invention to provide a highly reliable piping control device which uses a piping whip to prevent breakage of a high-temperature, high-pressure fluid piping, particularly a bent pipe portion, of a pressure tube nuclear reactor having a tube group structure.

In order to achieve the above object, in the present invention, a spacer is further provided between the lugs forming a pair, which is a condition of the conventional pipe restraint device, and the structure is such that the whip load is received by the spacer and the rod fixed thereto, and the structure is welded. By minimizing the distance between the spacers near the
The reliability of the piping restraint device is improved, and the paired lugs are divided into an outer ring and a lug fixed to the piping, and a spacer is further provided between the paired outer rings and the paired lugs. By integrating the device with a rod and making it removable from the lug fixed to the target piping, the on-site work required for installing this device can be minimized.
Further, in the apparatus which enables the automatic equipment for inspection during the service period after installation to be attached and detached, a detachable supporting member is provided between the lug and the spacer.

Hereinafter, one embodiment of the present invention will be explained with reference to FIGS. 9 to 11.

Lugs 6 are fixed to the target piping 1 by welding, and are arranged at intervals of 90° in the circumferential direction of the paired piping, with the expected breakage portion of the target piping, for example, a welded portion 5 in between. On the outside of the lug 6, a pair of outer rings 12 are fixed to the lug 6 by tightening bolts 14 and nuts 15, and a wire rope 1 is inserted through a stopper 18 attached to the outer ring 12.
They are integrated through 9. Between the pair of outer rings 12, a pair of spacers 13 are placed at a sufficiently short distance across the welded part 5.
13), through which the wire rope 19 is inserted with a sufficient gap.

Said lugs 6 have projections 17 each having a hole 10. Furthermore, spaces 16 large enough to allow the lugs 6 to be inserted are provided in the spacer 13 at intervals of 900 mm.

Moreover, between the spacer 13 and the rod 6, there is a supporting material 2.
0 is attached in a removable structure, and the attachment of the rod 6 of the spacer 13 prevents it from moving to the side.

The wire rope 19 is attached to the outer ring 12 by a stopper 18 in the state shown in FIGS. 9, 10, and 11, and is inserted through a spacer 13. To attach the paired outer ring 12 and spacer 13 to the lug 6 in the pressurized state shown in FIG. 9, rotate the lug 6 by 45 degrees from the state shown in FIGS. Insert it again and rotate it 45 degrees backwards, and
This is done by tightening the bolt 14 and nut 15 in the state shown in FIGS. After the outer ring 12 and spacer 13 are in place, the support 20 is attached. Similarly, removal is performed by a reverse operation.

According to this embodiment, a spacer 13 is attached between the pair of outer rings 12 via a wire rope 19, and
A support member 20 is installed between the lug 6 to which the outer ring 12 is attached and the spacer 13, and the structure is such that the whip load bearing (9) is supported by these spacers 13 and the wire rope 19 inserted through the spacer 13. By making the distance between adjacent spacers 13 as small as possible, the reliability of the pipe blocking device can be improved. Also, piping 1 of lug 6
Welding, integrating the outer ring 12 and wire rope 19, and inserting the wire rope 19 into the spacer 13 are performed at the factory, and when welding the joint between the straight pipe 1 and the bent pipe section 21 on-site, includes the outer ring 12 and the spacer 13.
and the wire rope 19 integrated into the welded part 5
By setting the device further apart to secure space for installing an automatic welder and attaching it to the lug 6 after welding the seam between the straight pipe and the bent pipe, the number of man-hours required on-site for installing this device can be reduced. can be reduced as much as possible.

Also, according to the same structural pressure, the distance between the paired lugs 6 can be increased to some extent by the support material 2o between them and the spacer 13, and the attachment and detachment of automatic equipment for inspection during the service period after installation is also possible. It can be made possible.

As described above, in the present invention, by providing a removable support material between the spacer and the lug to which the paired outer rings of the conventional wave (10) technique are attached, the space between the paired outer rings is improved. A spacer is installed to improve the reliability of the piping restraint device, and the integrated outer ring and spacer can be attached and removed from the lugs fixed to the piping, and the distance between the paired lugs can be inspected using an automatic welding machine or during service. The condition that a sufficient thickness can be secured to attach an automatic device for this can be applied to the bent pipe part as is.

In addition, we weld the lugs to the piping and integrate the outer ring, spacer, and wire rope at the factory, and after welding the joints of straight and curved pipes on-site, we attach the outer ring to the lugs and bolts and nuts. This has the effect of reducing the number of man-hours required for on-site work.

[Brief explanation of the drawing]

Figures 1 to 4 and Figures 6 to 8 are explanatory diagrams showing conventional piping control devices, Figure 5 is a structural diagram of the tube group immediately above and below the pressure tube reactor, and Figure 7 The figure is a sectional view taken along line A-A in FIG. 6, FIG. 8 is a cross-sectional view taken along line B-B (11) in FIG. 11 is a sectional view taken along line cc in the figure, and FIG. 11 is a sectional view taken along line DD in FIG. 1... Piping, 2... U-shaped stop rod, 3... Inner pipe,
4... Outer pipe, 5... Anticipated breakage part, 6... Lug, 7
...Rib, 8...Rod, 9...Protrusion, 1o.
...hole, 11...reactor, engineering 2...outer ring, 13
...Space? -114...Holt, 15...Nut, 16...Space, 17...Protrusion, 18...
- Stopper, 19...Wire rope' (12
)' 1st figure ``f3 z 3 fig.

Claims (1)

[Claims] 1. Consisting of a pair of lugs fixed to piping and a member connecting the lugs, a spacer into which the member connecting the lugs is inserted is provided between the pair of lugs, and the pair of lugs is connected to an outer ring and a member connecting the lugs. Divided into a lug and a lug that is fixed to the pipe,
In a piping restraint device for a pressure tube nuclear reactor, the outer ring and the spacer between the outer rings are integrated by a member connecting the lugs, and the lugs can be attached to and detached from the lugs fixed to the piping. A piping restraint device characterized in that a removable support member is provided between the spacer and the spacer.