JP2003074783A - Sealing device and sealing method for leakage in pipe end closing part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a sealing method for easily and rapidly sealing a leakage part without stopping a system when steam leakage occurs from a closing part projectingly formed in an end part of a steam pipe. SOLUTION: This sealing device has a pair of half split bushes 6 covering a constriction part 3 formed in a base of a bulge part 1 of the pipe end part from a radial direction; and a sealing device body 10 covering the bulge part 1 from an axial direction, having one end opening screwed on the split bushes 6, and formed with a sealant-filling opening 9 in the outer face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak-sealing jig and a sealing method for sealing a leak from a closing means provided upright at a pipe-end closing portion under normal use conditions of a main pipeline.

[0002]

2. Description of the Related Art As a conventional example, as shown in FIG. 7, a steam pipe 20 generally has a welded structure in order to prevent leakage during operation as much as possible. After confirming that there is no leakage, the power generation operation is performed. On the other hand, the steam pipe 20 is provided with a connection hole 35 used for calibrating various instruments at the time of regular inspection, and during operation, the closing means 2 which is generally a detachable plug is attached to form the pipe end closing portion 33. ing.

FIG. 1 schematically shows the structure of a general branch connecting portion 30 for providing this kind of pipe end closing portion 33. That is, an inner screw 36 is provided on the inner surface of the connection hole 35 of the tube end closing portion 33 so that a blind plug can be screwed as the closing means 2. Although not shown, a Teflon (registered trademark) seal tape, which is generally used, is meshed with the threaded portion of the inner screw 36 and the closing means 2 formed of a blind plug, and the tube end closing portion 33 of the tube end closing portion 33 is meshed with it. Completely seal.

The branch connecting portion 30 of this type having the pipe end blocking portion 33 has a short pipe 31 branch-connected to the steam pipe 20 which is the main pipe, and a shut-off valve 3 connected to the short pipe 31.
2 and the above-mentioned pipe end closing portion 3 connected to the shutoff valve 32
3 and. That is, the closing valve 32
A double closing system is formed by the pipe end closing portion 33 and the pipe end closing portion 33, and a reliable closing function is constituted. A welded structure is used at any of the connecting portions. Further, it is confirmed that the closing valve 32 has a complete closing function as a part of the main pipe line 20 at the time of the above-mentioned regular inspection.

However, it is possible that a leak could be discovered through the double-closure blind plug during power generation operation. Although there are various causes, in many cases, the wear of the sealing surface of the closing valve 32 progresses with the number of years of operation, and leaks that were overlooked because they were none or slight at the time of inspection became apparent. It is conceivable that wear and tear of the inner screw 36 may be a factor due to repeated attachment / detachment of the blind plug and the measurement pipe that are repeated for each inspection.

Conventionally, in such a case, the closing valve 32 is slightly operated in the opening direction and then completely closed, or the blind plug is removed and the Teflon seal tape is rewound and screwed again to complete the operation. We have worked hard to achieve the goal. However, in rare cases, it may happen that the sealing cannot be achieved by any of the measures, and the operation of the power plant may be forced to stop.

In general, the leakage flow rate from the double-closed system is insignificant and is generally several drops / min.
However, it may not be possible to leave it as it is in the BWR type nuclear power plant, even if the absolute amount is slight and there is no fear of increase in time. Since the droplets are radioactive, it is necessary to achieve complete sealing. Moreover, in the case of a nuclear power plant, since all the equipment is manufactured under the strict control from the material stage, it is not possible to easily replace it with the shutoff valve 32 of the same shape, which is also a great deal for new manufacturing. I need a wait time. In other words, stopping or replacing the operation has a great deal of economic loss. Under these circumstances, there is a need for a means for reliably sealing the leakage from the tube end blocking portion 33 while continuing the operation as an emergency measure at least until the next regular inspection.

As an example of the general conditions for the sealing operation in the above-mentioned first aid, it is necessary to consider the temperature of the tube end closing portion 33 of 100 ° C. and the internal pressure of the leak portion of 90 kgf / cm ² . The above describes the case of a nuclear power plant, but not only in power facilities but also in production lines of various industrial products and research facilities, even though it is a rare case that occurs in a double-closed system, the operation is stopped for a certain period of time. Is not allowed, and as a reliable first aid during that time, the pipe end block 3
It can be said that there are many cases in which 3 is desired to be completely sealed.

On the other hand, the sealant and its physical properties for sealing the leakage of various fluids generated under various temperature and pressure environments, or the sealant injection device 50 are sold by Nissei Kogyo Co., Ltd., for example. Basic countermeasures are in place by the sealing technology of the category such as "Kure Seal". Figure 8
Shows an example of a sealant injection device included in the above system.

The sealing agent is a semi-plastic synthetic resin material at room temperature and has an extremely high viscosity and appears solid at first glance. Once 8
When preheated to around 0 ° C., the viscosity is rapidly lowered, and after a few minutes, the viscosity is increased again to form a dense structure having hardness and elasticity peculiar to ambient temperature. However, 25
At 0 ° C or higher, the material polymer is once pyrolyzed, then the crystallization tendency is increased to further increase the hardness, and 200 kgf / cm ²
It has shear strength that reaches the above. The specific gravity is about 1.78. The main challenges in implementing sealing are:
The filler enclosing structure and encapsulation method were created in accordance with the configuration of each leaking point, the leaking substance, the environment and mode of leaking, and there was no precedent for the tube end blocking part.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when there is a leak in the pipe end closing portion 33 closed by the closing means 2, at least the main pipeline 20 is in an active state (system). It is an object of the present invention to provide a leak-sealing jig and a sealing method capable of performing a leak-sealing operation while being in the operating state.

[0012]

[Means for Solving the Problems] That is, according to the invention described in claim 1, a pipe end block portion in which an enlarged portion (1) is formed at a pipe end portion and a tip end thereof is closed by a closing means (2) is provided. In the jig that seals when leakage occurs at the closed end of the pipe end, use the inner circumference (4) aligned with the constricted part (3) on the upstream side of the pipe end adjacent to the enlarged part (1). Has and external threads on the outer circumference
(5) is formed, a pair of half bushes (6) bisected in a plane including the axis, and a cylinder having an inner circumference not less than the outer circumference of the enlarged portion (1) and having a bottom (7) Sealing jig that is formed in a circular shape, has an inner thread (8) that matches the outer thread (5) on the inner circumference of the opening end, and has an opening (9) for filling the sealant on the outer surface. A jig for leak-sealing a pipe end blocking portion, comprising a main body (10).

According to a second aspect of the present invention, in the first aspect, the opening is provided in the bottom portion (7) of the sealing jig body (10).
(9) is formed, an inner screw (11) for connection is formed in the opening (9), and a flange portion (12) is projected on the outer periphery of one end in the axial direction of the pair of half bushes (6). In addition, the fitting sealing surface (13) for fitting a screw tool is formed on the outer periphery of the flange portion (12) of the pipe end closing portion for sealing leakage.

According to a third aspect of the present invention, in the first or second aspect, the sealant injection path (37) for communicating the opening (9) with the inside of the sealing jig body (10) is provided. The opening (9) can be opened and closed while the sealant injection device (50) is connected,
This is a leak-sealing jig for pipe end blockages, which is provided with at least opening closing means (16) for preventing the flow of the sealant from the inside of the sealing jig body (10) toward the opening (9).

The invention according to claim 4 is the same as claim 1 or claim 2, wherein one end has a bottom portion (7) of the sealing jig body (10).
It is configured to be able to open and close while the exhaust passage (14) whose other end is open to the outside of the sealing jig body (10) is connected to the inner surface and the sealant injection device (50) is connected to the opening (9). This is a leak-sealing jig for pipe end blockage, which comprises an exhaust passage closing means (15) for closing the exhaust passage (14).

According to a fifth aspect of the present invention, the leak-sealing jig according to any one of the first to fourth aspects is used.
In the sealing method for sealing the pipe end closing part, the outer circumference of the constricted part (3) of the pipe end closing part is fitted with the pair of half bushes (6) from the radial direction thereof, and the sealing is performed. The stopper jig body (10) is fitted on the pipe end from its axial direction, and the pair of half bushes (6) are screwed to the inner screw (8), and then the sealing jig body ( A pipe characterized by filling the inside of the sealing jig main body (10) with a sealant by means of a sealant injection device (50) connected to the opening (9) of (10) and curing it. This is a method of sealing the end blocking portion.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a leak sealing jig 1 according to the present invention.
FIG. 2 is a front view showing a state in which the pipe end closing portion 33 is attached and a sealant injecting device 50 is further connected to the example.
FIG. 2 is a sectional view taken along the line II-II of FIG. FIG. 3 is an explanatory diagram for mounting the leak sealing jig of the present invention. In FIG. 1 and FIG. 3, the pipe end closing portion 33, which is the target of the leak sealing jig of the present invention, can be attached to the pipe end portion having the enlarged portion 1 and the constricted portion 3 relative to the enlarged portion. Is configured.

The half-bush 6 has an inner circumference 4 aligned with the constricted portion 3 and an outer thread 5 on the outer circumference, and is made up of a pair bisected in a plane including the axis. Further, the half-bush 6 has a flange portion 12 protruding from the outer periphery of one end thereof.
And a fitting surface 13 formed on the outer periphery of the flange portion 12 for fitting a screw tool. The fitting surface 13 is formed in a hexagonal shape, but may be formed of a pair of parallel two surfaces.

The sealing jig body 10 is formed in a cylindrical shape having an inner diameter larger than the maximum outer diameter of the enlarged portion 1 and has a bottom portion 7 at one end.
Have. An inner screw 8 is formed on the inner surface of the opening end so as to match the outer screw 5 of the half bush 6. An opening 9 for filling the sealant is formed at the center of the bottom portion 7.
The sealant injection passage 37 that communicates the opening 9 with the inside of the sealing jig body 10 has the opening closing means 16 made of a bolt, and the injection passage 37 is openably and closably closed by the opening and closing. The opening closing means 16 is configured to be able to be opened and closed while the sealant injection device 50 is connected to the opening 9 when the sealant is injected into the sealing jig body 10 through the opening 9. .

This is so that after the sealant is injected, the injection passage 37 is closed by the opening closing means 16 so that the sealant injection device 50 can be directly removed.
The opening closing means 16 prevents the sealant from flowing out from the opening 9. The leakage sealing jig composed of the half bush 6 and the sealing jig body 10 is
When the sealant is filled, even if the mating surface of the half bush 6 and the gap between the screwing portions of the outer screw 5 and the inner screw 8 are closed, it has sufficient strength to withstand a predetermined filling pressure. Is configured.

FIG. 4 is a vertical sectional view of another embodiment of the present invention, and FIG. 5 is a sectional view taken along the line VV of FIG. 4, in which the opening 9 of the sealing jig body 10 has an outer periphery of the bottom portion 7. It is provided with a seat to which the sealant injecting device 50 can be attached and an inner screw 11.

FIG. 6 is a longitudinal sectional view of a main part of still another example of the leakage sealing jig of the present invention, one end of which is the sealing jig body 10.
The exhaust passage 14 is opened to the inner surface of the bottom portion 7 and the other end is opened to the outer surface of the sealing jig body 10, and the exhaust passage closing means 15 is provided to close the exhaust passage 14. The exhaust passage closing means 15 is configured to be opened and closed while the sealant injection device 50 is connected to the opening 9. In the illustrated example, the bottom portion 7 is provided for convenience of processing.
The outer surface side of the exhaust passage 14 opening to the inner surface of the
The exhaust passage 14 is closed by previously inserting the rod end of the bolt into a round hole having a diameter larger than that of the exhaust passage 14 and intersecting with the exhaust passage 14. This is to make it easy for the internal air to flow out when injecting the mounting medium.

[0023]

[How to use] The half-divided bush 6 which is equally divided in FIG. Further, since the inner circumference 4 is formed so as to be aligned with the constricted portion 3, it can be mounted without any apparent gap between the constricted portion 3 and the half bush 6. Also, the sealing jig body 1
0 is fitted from the axial direction with an inner diameter not less than the maximum outer diameter of the enlarged portion 1 formed by the tube end blocking portion 33, and the enlarged bush 1 is screwed into the inner periphery of the opening end of the enlarged portion 1. Store and hold in the leak sealing jig.

In FIG. 2, the flange portion 12 projecting from the half bush 6 has a fitting surface 13 for fitting a screw tool, and the fitting surface 13 leaks to facilitate the assembly work of the sealing jig. To do. Further, since the flange portion 12 is provided so as to project, the outer screw 5 is brought into contact with the end surface of the sealing jig body 10 by contacting it.
The screwing distance between the inner screw 8 and the inner screw 8 can be maintained as a predetermined distance. As a result, the leak sealing jig can be set to safely and reliably withstand the internal pressure that acts when the sealant is filled.

Therefore, a solid sealant is loaded into the sealant injecting device 50, and if possible, the temperature is raised to almost the same temperature as the pipe end closing portion 33 in a state of being integrated with the leaky sealing jig, so that the leaky seal can be quickly sealed. A stop jig is attached to the tube end blocking portion 33. It is preferable to use hot water to raise the temperature. Then, the sealant is leaked and injected into the sealing jig. Since the sealing jig body 10 has the opening 9 for filling the sealing agent, the sealing agent injecting device 50 is directly or indirectly connected to the opening 9 to seal from the spout hole 51. The agent can be press-fitted into the leak-sealing jig through the opening 9 and the injection path 37.

At this time, when the leak sealing jig is positioned vertically, the exhaust passage closing means 15 shown in FIG. 6 is opened and air is discharged from the small chamber to the outside. When the discharge is completed, the exhaust passage closing means 15 closes the exhaust passage 14. Then, after filling the inside with the sealant, the supply pressure of the sealant is increased, and the sealant is supplied while maintaining at least the internal pressure at a predetermined pressure equal to or higher than the pressure of the main pipeline 20 (that is, the leak pressure). Continue.

The sealant is successively applied to the mating surfaces of the half bushes 6, the gap between the outer threads 5 and the inner threads 8 in a spiral shape, the mating surfaces of the half bush 6 and the constricted portion 3, and the like. invade. The sealant that has passed through these gaps leaks and is pushed out of the sealing jig. Eventually, the encapsulant will begin to cure at ambient temperature. Therefore, the opening closing means 16 of FIG.
Then, the injection path 37 is closed, and then the sealant injection device 50 is removed to complete the sealing operation.

[0028]

According to the invention described in claim 1,
The pair of half bushes 6 are aligned with the outer circumference of the constricted portion 3 of the enlarged portion 1, the sealing jig main body 10 is fitted on the enlarged portion 1, and the inner screw 8 thereof is screwed onto the outer screw 5 of the half bush 6. Since the sealing agent is attached to the inside of the sealing jig body 10 through the opening 9 on the outer surface of the sealing jig body 10, and the outer periphery of the closing means 2 formed in the enlarged portion 1 is sealed with the sealing agent, Closing means 2 of the enlarging part 1
It is possible to quickly and reliably seal the leakage caused by

According to the present invention as set forth in claim 2, since the flange portion 12 is projectingly provided on the half bush 6 and the fitting surface 13 is formed on the outer periphery of the flange portion 12, the sealing jig is formed. The split bush 6 can be securely screwed and fastened to the opening of the main body 10, and a highly reliable leak-sealing jig can be provided. According to the present invention as set forth in claim 3, since the opening closing means 16 is provided in the injection path 37 of the sealing jig main body 10, after filling the inside of the sealing jig main body 10 with the sealant, If the injection passage 37 is closed by the opening closing means 16, the opening 9
The sealant injecting device 50 connected to can be immediately removed, and the work can be completed quickly.

According to the present invention as set forth in claim 4, since the exhaust passage 14 and the exhaust passage closing means 15 for opening and closing the exhaust passage 14 are provided, the sealing agent is sealed in the sealing jig body 10. At this time, the air inside can be smoothly discharged to the outside of the sealing jig body 10. According to the present invention described in claim 5, it is possible to easily seal the leakage from the tube end blocking portion without stopping the system.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a usage state of a leak sealing jig of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is an explanatory view of mounting the leak sealing jig.

FIG. 4 is a vertical sectional view showing another embodiment of the leak-sealing jig of the present invention.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a vertical cross-sectional view of a main part of still another leakage-sealing jig of the present invention.

FIG. 7 is a partially cutaway explanatory view of a pipe end blocking portion which is a target of the leakage sealing jig of the present invention.

FIG. 8 is a perspective view of a sealant injection device 50 connected to the leak-sealing jig of the present invention.

[Explanation of symbols]

1 Enormous section 2 Blocking means 3 constriction 4 inner circumference 5 external screw 6 half bush 7 bottom 8 inner screw 9 openings 10 Sealing jig body 11 Internal screw 12 Flange 13 Fitting surface 14 exhaust path 15 Exhaust path closing means 16 means for opening and closing 20 Main pipeline (steam piping) 30 branch connection 31 Short tube 32 Shut-off valve 33 Pipe end block 34 Conduction hole 35 connection hole 36 Internal screw 37 injection path 40 buried bolt 50 Sealant injection device 51 pouring hole 52 injection gun 53 infusion pump 54 tubes 55 Sealant

Claims (5)

[Claims] 1. A pipe end closed portion having an enlarged portion (1) formed at the pipe end portion and having a tip closed by a closing means (2), and is sealed when leakage occurs at the pipe end closed portion. In the stopping jig, the constricted part (3) on the upstream side of the pipe end adjacent to the enlarged part (1)
A pair of half bushes that have an inner circumference (4) aligned with the outer circumference and external threads (5) formed on the outer circumference, and are bisected in a plane that includes the axis.
(6) and an inner circumference that is equal to or greater than the outer circumference of the enlarged portion (1), and is formed in a cylindrical shape having a bottom portion (7).
A sealing jig body (10) having an inner screw (8) aligned with (5) and an opening (9) for filling the sealant on the outer surface, and Leakage sealing jig. 2. The opening (9) according to claim 1, wherein the opening (9) is formed in the bottom portion (7) of the sealing jig body (10), and an internal screw (11) for connection is formed in the opening (9). A flange portion (12) is provided on the outer periphery of one end portion of the pair of half bushes (6) in the axial direction and the flange portion (1
A leak-sealing jig for a pipe end closed portion, wherein a fitting surface (13) for fitting a screw tool is formed on the outer periphery of (2). 3. The sealant injection passage (37) for communicating the opening (9) with the inside of the sealing jig body (10) according to claim 1 or 2, wherein the opening (9) is sealed. An opening closing means (16) configured to be openable / closable while the stopper injection device (50) is connected, and for preventing the sealant from flowing from at least the inside of the sealing jig body (10) toward the opening (9). ) A leak-sealing jig for pipe end blockages. 4. The exhaust passage according to claim 1, wherein one end is opened to the inner surface of the bottom (7) of the sealing jig body (10) and the other end is opened to the outer surface of the sealing jig body (10). (14) and opening (9)
An exhaust passage closing means (15) for closing the exhaust passage (14) configured to be able to be opened and closed while the sealant injecting device (50) is connected to, and a leakage sealing jig for a pipe end closing portion. . 5. A sealing method for sealing a pipe end closing part using the leaky sealing jig according to claim 1, wherein the constricted part of the pipe end closing part ( The outer circumference of 3) is fitted with the pair of half bushes (6) from the radial direction, and the sealing jig body (10) is fitted to the pipe end from the axial direction, and the inner screw (8) to the pair of half bushes (6)
Then, using a sealant injection device (50) connected to the opening (9) of the sealing jig body (10), the sealant is injected into the sealing jig body (10). A method for sealing a tube end closed portion, which comprises: