JPH09297197A - Piping cutting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piping cutting method that can positively prevent scatter or leakage of internal liquid at the time of cutting a piping in which liquid containing radioactive material or the like exists and can be applied to pipings of every direction, material and diameter. SOLUTION: A first hole 2 is bored in an upper part of a piping 1 at a cut part, and second holes 3 are formed with a prescribed space, in two upper places on both axial sides of the first hole 2. A bag body is installed being inserted in a contracted state into each second hole 3. Backup material, a foaming curable material is filled into the bag body from an opening part, and the bag body is expanded by the internal pressure of the filled backup material to close the opening part. The cut part and both axial sides thereof are partitioned to such an extent as not to flow through to each other. After filler 8 is hardened, the piping 1 at the cut part is cut by a cutting tool.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe cutting method for cutting a fluid consisting of a liquid or a gas inside a pipe without leaking to the outside, and particularly to radioactive waste in maintenance and repair work of nuclear facilities. The present invention relates to a pipe cutting method suitable for cutting a pipe containing a harmful substance therein.

[0002]

2. Description of the Related Art Conventionally, in the method of cutting a pipe containing a harmful fluid that should not leak, and particularly in the method of cutting a pipe containing a pollutant such as radioactivity in a nuclear facility, such a harmful Careful treatment is performed so that there is no risk of damaging workers in the facility by leaking out and diffusing various fluids and liquids containing radioactive substances to the outside.

For example, after a protective facility for diffusion prevention is provided around the pipe to be cut, a cutting pan is installed below the pipe when cutting, and cutting is performed while receiving the liquid leaking from the inside of the pipe with this pan. There is work.

In recent years, a method has been used to prevent the liquid from flowing out from the cutting portion by compressing and crushing a pipe made of a steel pipe or the like to be cut and then cutting. Furthermore, the pipe cutting method developed by the present applicant is as follows.
A hole is bored in the pipe at the position to be cut, and high-pressure air is blown into the pipe through the hole to move the fluid from the position inside the pipe to be cut to the periphery.

Next, a backup material is injected from the hole, and high-pressure air is blown to blow the backup material to the left and right to form a void in the cut portion, and after the backup material is cured, a filler is injected into the void and cured. After this, the pipe is cut and removed.

[0006]

However, among the conventional pipe cutting methods described above, in the method of cutting while receiving the liquid in the tray, the liquid adheres to the cutting tool when the pipe is cut. Further, there is a problem that the radioactive contamination may spread due to the liquid scattering from the work tool to the surroundings.

Further, in the method of cutting the pipe after crushing it, the liquid may remain inside the crushed part of the pipe and the liquid may flow out from a slight gap, so that the liquid is completely enclosed. There was a problem that I could not.

Further, the pipe to be cut is a vinyl chloride pipe,
In the case of a material such as a cast iron pipe, there is a problem that this method cannot be applied because the material is damaged without being crushed.

Further, in the pipe cutting method previously developed by the present applicant, when the pipe to be cut has a small diameter, the backup material fires inside the pipe to increase the volume and to leave a gap in the pipe. The filling material can be reliably blocked by partitioning without pipes.However, if the pipe has a large diameter, the injected backup material will flow out over a wide area at the bottom of the pipe, and even if it fires during curing, the inside of the pipe will However, there was a problem that the fluid could leak from the cutting portion to the outside.

The same applies to the case of a pipe extending in the vertical direction, and there is a problem that the injected backup material flows downward and the inside of the pipe cannot be sufficiently partitioned.
Therefore, the present invention has been made by paying attention to the above-mentioned unsolved problems of the related art, and it is possible to reliably prevent scattering or leakage of the internal liquid at the time of cutting a pipe in which a liquid containing a harmful substance or the like is contained, Moreover, it is an object of the present invention to provide a pipe cutting method applicable to pipes of any direction, material and diameter.

[0011]

In order to solve the above problems, the present invention relates to a pipe cutting method for cutting a pipe containing a fluid, wherein a first hole is provided at a position to cut the pipe. And a second hole is formed on both sides of the first hole in the axial direction, and a bag is inserted into the pipe through the second hole and installed, and the bag is backed up inside the bag. A pipe cutting method in which a pipe is expanded by injecting a material to partition the inside of the pipe, a filler is injected from the first hole into the pipe between the bags, and the pipe is cut after the filler is cured. I will provide a.

The present invention can be widely applied to gas pipes or liquid pipes, and particularly to pipes for nuclear facilities. Thus, a first hole is formed in the pipe at a position to be cut with a size such that the gas or liquid inside the pipe does not flow out to the outside, and the first hole is formed on both the left and right sides of the first hole. Two holes are formed, a bag is inserted and installed in the second hole, and a gas, a liquid, or the like is injected into the inside from the opening of the bag to inflate the bag so that the bag is piped. A partition wall for the filler is formed as an inner partition wall.

Further, since the filler is injected into the cut portion surrounded by each bag, the filler flows and diffuses even if the filler has a high fluidity or a large diameter pipe. It is held in place without any gaps.

Furthermore, each cutting portion of the pipe divided by a cutting tool or the like surely plugs the inside of the pipe with a filling material. On the other hand, a first hole is formed at a position to be cut in a pipe extending in the vertical direction, and a second hole is formed below the first hole in the pipe axial direction. The bag body is inserted into the pipe through the hole, the bag body is inflated to partition the inside of the pipe into upper and lower parts, and the filler is injected into the pipe through the first hole. There is provided a method for cutting a pipe, which comprises cutting the pipe after curing.

Thus, particularly when cutting the pipe extending in the vertical direction, the second hole is formed axially below the first hole to insert and install the bag body. The bag is inflated by the same method as described above to form a section below the cut portion inside the pipe.

Further, when the filler is injected through the first hole, it is successively accumulated in the upper part of the bag body and filled in the entire cutting portion to be hardened, and after cutting, the fluid inside the pipe is plugged. On the other hand, the bag body is characterized by having elasticity.

Therefore, for example, when the bag body is made of a material such as rubber, when a filling material made of gas or liquid is injected into the bag body and pressure is applied from the inside of the bag body, the elasticity of the rubber facilitates the operation. It expands and partitions the inside of the pipe without gaps.

The same applies to the case where the fluid is a fluid such as a liquid or gas containing a harmful substance.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the pipe cutting method of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a pipe. Here, in the case where a relatively large-diameter pipe 1 containing a harmful fluid made of a liquid containing radioactive waste inside the pipe 1 is removed in the nuclear facility 20 Has been applied.

The pipe 1 extends vertically and horizontally through the wall 21 and the slab 22 around the room space inside the nuclear facility 20, and here, A- of the pipe 1 arranged in the horizontal direction. Remove between B.

As shown in FIG. 2, a first hole 2 having a small diameter of about 20 mm is bored in the upper portion of the pipe 1 at the cutting portion, and further, the first hole 2 is axially formed. The second holes 3 are formed in the upper two places on both sides at predetermined intervals.

Then, the bag body 4 is inserted and installed in the second hole 3 in a contracted state. The bag body 4 is made of elastic rubber here, and the opening 5 is installed outside the pipe 1 through the second hole 3.

Then, from the opening 5 into the bag body 4,
The backup material 6 which is a foam hardening material is injected, and the bag 4 is inflated by the internal pressure of the injected backup material 6 to such an extent that the bag 4 comes into close contact with the inner peripheral surface of the pipe 1.

Next, when the opening 5 is closed to prevent backflow of the injected backup material 6 and a predetermined time elapses, the volume of the backup material 6 increases while generating bubbles, and the cutting portion inside the pipe 1 increases. And the both sides in the axial direction are hardened by partitioning them so that they cannot flow through each other.

As the backup material 6, specifically, a foamed resin-containing resin material such as foamed polystyrene, foamed polystyrene, foamed urethane, or foamed concrete can be used. Further, the term "curing" as used herein does not mean only complete curing, but also includes curing that is sufficient to seal the fluid 10 and the like.

In this embodiment, the case where the bag 4 is inflated by the backup material 6 has been described. However, the bag 4 is filled with a gas such as air or a non-hardening liquid such as water, and the opening 5 of the bag later. It is also possible to form a compartment without a gap inside the pipe 1 by closing the backup material 6 so that it does not leak out.

Next, the filler 8 is injected from the first hole 2 into the cut portion between the bags 4. As the filler 8, here, a mortar containing an expansive material is used, which is filled without a gap in the cutting portion and then hardened without shrinking.

Other than this, the filler 8 may be cement containing an expansive material, epoxy resin, or the like. Therefore, the filler 8 expands with curing and is filled without any gap, and does not shrink during curing, so that a gap is prevented from being generated in the cut portion.

Then, as shown in FIG.
After hardening to the extent that can be sheared, a saucer (not shown) is installed under the pipe 1 of the cutting portion for safety, and cutting is performed by a cutting tool (not shown).

At this time, the filler 8 disposed in the cut portion of the pipe 1 is sheared, and the filler 8 is filled with no gap and plugged, so that the fluid 10 inside the pipe 1 is filled with the filler 10. 8 and the bag body 4 are restrained and sealed inside the pipe 1. Here, the hardening of the filler 8 does not mean only complete hardening, but also includes hardening to a degree sufficient to plug the blown-off fluid or the like.

Thus, when the cutting portion filled with the filling material 8 is cut, only the filling material 8 filled with no gap inside is sheared, the fluid 10 leaks from the cutting portion, or the cutting tool is cut. The fluid 10 does not adhere to 6 and does not diffuse to the surroundings, so that the cutting operation can be performed safely.

Furthermore, it is not necessary to crush or deform the pipe 1 at the cutting portion, and the pipe 1 is made of any material.
Can be applied to Further, the bag body 4 is installed through the second hole 3 inside the pipe 1, and the inside of the pipe 1 is filled with the backup material 6, so that the backup material 6 is piped even if the diameter of the pipe 1 to be cut is large. The bag body 4 expands by the internal pressure of the backup material and can divide the cut portion and its left and right in the axial direction without a gap without spreading over a wide area of the bottom portion.

Further, the bag body 4 expands so as to divide the cut portion and the pipe 1 in which the fluid 10 is present, and even if the filler 8 is a highly fluid substance, it spreads over a wide area at the bottom of the pipe 1. Instead, the voids 7 formed in the cut portion are filled without any gap.

On the other hand, since the filler 8 contains the expansive material, it is injected into the cut portion and then expanded, and does not contract after curing, so that the fluid 10 does not leak to the outside.

Further, as shown in FIG. 1, the pipe 1 between A and B can be removed by cutting the portion B by the same method as described above. Next, another embodiment of the present invention will be described.

The present invention will be described with reference to FIG. 1 in which the space between C and D of the pipe 1 extending in the vertical direction is removed. First, as shown in FIG. 4, the first hole 2 is formed in the side portion of the pipe 1 at the position C to be cut by the same method as in the above embodiment.

Next, a second hole 3 is formed on the axially lower side of the first hole 2, a bag body 4 is installed inside the second hole 3, and a backup material is provided inside the bag body 4. 6 is injected and expanded to partition the inside of the pipe 1.

Further, the filler 8 is injected from the first hole 2 to fill the cut portion without any gap. At this time, the filling material 8 inside the pipe 1 is poured and then accumulated, so that the filling material 8 is sequentially filled from the lower side of the cut portion and hardened.

Then, as shown in FIG. 5, the filler 8 is sheared by cutting the cut portion of the pipe 1, and the fluid 10 inside the pipe 1 is plugged to prevent leakage of the fluid 10 to the outside. it can.

Further, as shown in FIG. 1, C to be repaired by cutting the D portion in the same manner as described above.
The pipe 1 between -D can be removed. In addition, although the case where the pipe 1 extending vertically in the room is cut has been described in the present embodiment, the present invention is not limited to this, and the filler 8 at the cut portion is accumulated below the pipe 1. It can also be applied to the pipe 1 that is arranged to be inclined in a diagonal direction.

Further, in the above embodiment, the fluid 1
Although the case where 0 is a liquid containing a radioactive substance has been described, the present invention is not necessarily limited to this, and it is needless to say that it can be applied to the fluid 10 made of any other liquid.

Besides this, the present invention can be applied to the case where the fluid 10 is a gas containing a harmful substance or the like. Further, in this embodiment, expanded mortar is applied to the filler 8, but other materials containing various expanders such as expanded cement and expanded concrete can be applied. Other than this, a solvent type adhesive or the like can also be applied.

[0043]

As described above, according to the first aspect of the present invention, the bag body is installed on both axial sides of the position where the pipe is to be cut, the bag body is inflated, and the filling material is injected into the pipe between them. Since it hardens and cuts the pipe, even if the pipe has a large diameter or extends in the vertical direction, the backup material does not flow and diffuse, and a partition is formed in the pipe to ensure fluid flow. And the filler can be filled into the cut portion without any gap.

Further, without performing the complicated work of crushing and deforming the pipe, leakage of the fluid to the outside of the pipe is prevented only by the work of injecting the backup material and the filler, and the cutting work is performed on the pipe of any material. Is performed simply and economically.

On the other hand, according to the second aspect, when cutting the pipe extending in the longitudinal direction, the second hole is formed on the axially lower side of the first hole to insert the bag body. Install and inflate this bag to form a section below the cutting part inside the pipe, so that the bag is installed only at the bottom without installing in two places, and the cutting work is performed reliably. You can

According to the third aspect of the invention, since the bag body is stretchable, the bag body is tightly adhered to the inside of the pipe without a gap when the bag body is inflated so that the fluid can be surely plugged. Further, in claim 4, when the fluid is a fluid containing a harmful substance, the work can be performed safely without affecting the worker who performs the cutting work. Particularly, when the fluid is a harmful substance such as radioactive waste, the safety of the work is secured without leaking the fluid to the outside of the pipe and damaging the surrounding environment.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a nuclear facility applied to a pipe cutting method according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a cutting portion showing a construction procedure of the pipe cutting method according to the embodiment of the present invention.

FIG. 3 is a side sectional view of a cutting portion showing a construction procedure similar to FIG.

FIG. 4 is a side sectional view of a cutting portion showing a construction procedure of a pipe cutting method according to another embodiment of the present invention.

5 is a side sectional view of a cutting portion showing a construction procedure similar to FIG.

[Explanation of symbols]

 1 ... Piping 2 ... First hole 3 ... Second hole 4 ... Bag 5 ... Opening 6 ... Backup material 8 ... Filling material 10 ... Fluid 11 ... Compressor 20 ... Nuclear power Facility 21 …… Wall 22 …… Slab

Claims (4)

[Claims] 1. A pipe cutting method for cutting a pipe in which a fluid is contained, wherein a first hole is formed at a position to be cut in the pipe, and a second hole is formed on both sides of the first hole in an axial direction. A hole is bored, a bag is inserted into the pipe through the second hole and installed, and a backup material is injected into the bag to inflate the bag to partition the inside of the pipe,
A pipe cutting method comprising injecting a filler into the pipe between the bags from the first hole and cutting the pipe after the filler is cured. 2. A pipe cutting method for cutting a pipe having a fluid therein and extending in a longitudinal direction, wherein a first hole is formed at a position to be cut in the pipe, and the first hole is formed. A second hole is formed on the lower side in the axial direction of the pipe, a bag is inserted into the pipe through the second hole and installed, and the bag is inflated to partition the inside of the pipe. A pipe cutting method comprising injecting a filler into the pipe through a first hole and cutting the pipe after the filler is cured. 3. The pipe cutting method according to claim 1 or 2, wherein the bag has elasticity. 4. The pipe cutting method according to claim 1, wherein the fluid is a fluid containing a harmful substance.