JP2021169201A - Piping repair method and piping repair materials - Google Patents

Abstract

To provide a method of repairing pipes by using fiber-reinforced polymer materials in pipe repair and its dried fiber materials.SOLUTION: When applying resin around a defect in a piping line, the fiber material is attached to the interior and exterior of the resin to hold and reinforce the resin, and the resin is applied to the fiber material before it is attached. In addition, in order to control the flow of resin, the fiber material is configured in a layered or cylindrical form to wrap the resin, and resin is applied and inserted inside the fiber material before it is attached to the piping line. In addition, in order to facilitate the retention and reinforcement of the resin used for repair, a fiber material with a function to suppress the flow of the applied resin is used.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pipe repair, particularly to a method of repairing a pipe using a fiber reinforced polymer material and a material thereof.

Plumbing is ubiquitous and widely found in residential, commercial and industrial applications, such as manufacturing processes, chemical transport, energy transport, water supply, heating / cooling / sewage facilities, and chemical wastewater / sewage. It is used for the recovery of chemicals and compounds. The peak of their installation was 30 to 40 years ago, and many plumbing lines are still in use.

Piping defects and damage troubles occur due to mechanical damage, corrosion, erosion, coating damage, heat insulation damage, incorrect operating conditions, and the like.

Generally, the repair technique uses a metal sleeve arranged around a part of the pipe for reinforcement. Welded and non-welded mechanical sleeves are installed to cover the longitudinal and radial directions of the pipe to prevent leaks and repair defects. The sleeve can repair latent defects and corroded parts inside and outside the pipe. Reinforcing technology that welds a sleeve to a predetermined position around a pipe and reinforcement technology that uses a sleeve that is mechanically attached to a pipe without welding are familiar repair methods that are widely used in the industrial world. Proper installation of the sleeve requires excellent welding technicians and work technicians, and its training is very costly. Further, the repair using the welded sleeve and the non-welded sleeve of the piping line has a weakness that the repaired portion of the piping line is embrittled and residual stress is generated.

In general, it is desirable from the viewpoint of operating cost to repair the piping without requiring a plant shutdown period while the piping line is still in operation. In addition to permanent repairs, even extending the life of a temporary repair to the specified long-term repair period can avoid sudden outages and contribute to a significant cost reduction.

Non-welding sleeves do not require welding or the use of fire, so they are easier to install than welded sleeves, but they need to be positioned with clamps, bolts, etc. It is said that it is necessary and complicated compared to the welding method, and as a result, the pipe repair using the non-welding sleeve is more expensive than the repair using the welding sleeve. However, repairs using non-welded sleeves are often adopted because they have the advantage of avoiding welding at repair sites such as piping line areas and chemical and petrochemical process areas.

As mentioned above, both welded and non-welded mechanical sleeves are costly, require a high degree of skill, increase piping stress, and require the shutdown of piping lines. .. For these reasons, a more improved method for repairing pipes has been desired.

On the other hand, repair with resin often does not use a reinforcing material when it is simply performed, but it has a drawback that it does not have appropriate strength for repairing medium-pressure and high-pressure piping lines. In order to compensate for this, a method of constructing an integrally molded structure around a damaged pipe by using a composite material fiber for an epoxy material and another resin has been attempted. Generally, various fibers, polymers, resin prepolymers, adhesives and other components are utilized to form composite structures around damaged parts of piping. Glass fiber is often used for repairing such composite materials. Compared with the case of using the mechanical sleeve or the welding type sleeve, it is possible to omit various costs incurred as described above, and it is one means that can reduce the repair cost of the deteriorated pipe.

However, the use of these repair composites is that in the methods used so far, as pointed out by Japanese Patent No. 4955569, each layer of fiber is dipped in resin and moistened before the fiber is attached around the pipe. It takes a lot of labor such as requiring. A method according to Japanese Patent No. 4955569 has been proposed as a method for avoiding these complicated preparations.

The method according to Japanese Patent No. 4955569 is characterized in that, after surrounding the defective portion and once attaching reinforcement such as a fiber material, a mechanical sleeve-shaped container called a storage component is exteriorized and liquid resin is injected into the exterior. However, in actual construction, it is extremely difficult to uniformly charge the liquid resin. A method of applying a brush before mounting the component has also been proposed, but even when such an auxiliary device is used, it is difficult to control the gap between the component and the fiber material. In many cases, the component is arranged in contact with the fiber material, but since the flow path for injecting the liquid resin is non-uniformly configured, uniform injection cannot be realized even when pressure is applied. In particular, since the repair pipe to be targeted is cylindrical, the pipe is arranged vertically when it is arranged horizontally, in the axial direction when it is arranged vertically, and at an intermediate position. Similarly, in valves, elbows, bent pipes, etc., it is difficult to achieve uniform injection into the part to be adhered against gravity.

Patent No. 4955569 proposes a method of injecting a liquid resin into a component by providing a spout and applying external pressure as necessary, but the injected liquid resin has a viscosity before the viscosity increases over time. It must be done efficiently, and it is impossible to adopt a liquid resin with high viscosity at the initial stage. On the other hand, a material having a low initial viscosity has a drawback that it takes a long time to cure.

In order to solve the above problems, the present inventor
When applying resin around a defect in a part of the piping line, when attaching the dry fiber material to the interior and exterior of the resin to hold and reinforce the resin, after applying the resin to the piping line side of the dry fiber material. Piping line repair method characterized by mounting,
When the resin is applied to the dry fiber material, the dry fiber material is formed in a layered or tubular shape so as to wrap the resin with the dry fiber material in order to suppress the flow of the resin, and the resin and the dry reinforcing material are attached to the piping line. Piping line reinforcement method, which is characterized by
2. Described piping line repair method,
A dry fiber material having a function of suppressing the flow of the applied resin by providing a convex portion such as a linear or lattice shape on at least one side surface of the dry fiber material in order to easily hold and reinforce the resin used for repair. ,
In order to easily hold and reinforce the resin used for repair, the dry fiber material is configured in a tube shape, and the resin to be applied is loaded on the inner surface of the tube to suppress and hold the flow of the dry fiber material. ,
By providing.

According to the present invention, when repairing pipes, welding and mechanical reinforcements that require complicated and precise work can be omitted or reduced. , The necessary piping reinforcement can be provided.

According to the method of the present invention, the dried fiber material can be formed in the form of a sheet or a tube, and can be formed in multiple layers as needed. Specifically, it is possible to secure the thickness of the resin required for the repair work regardless of the complicated piping position and the shape of the piping. That is, it is possible to prevent unintentional loss of resin and reduction in thickness during construction, which not only facilitates repair work but also improves the quality of repair work, thus improving the reliability of repair work. Is enhanced.

When using a sheet-shaped dry fiber material, use sheets of various dimensions according to the damage situation of the piping to be reinforced, and in order to make the work easier, stack larger sheets one by one, and not only paste them. It is also possible to wind the pipe in the circumferential direction and to deploy it in a spiral or axial direction. Not only applying the resin to only one side, but also holding the resin in the sandwich structure with a sheet of dry fiber material facilitates the construction work. Resins of various viscosities can be used, and it is also effective to temporarily hold the resin in a viscous state that makes it easy to work and then apply it under appropriate conditions. When a resin material having a low viscosity is used, it is possible to suppress the flow of the resin by using a dry fiber material having a convex portion such as a linear or lattice shape on at least one side surface, and it is possible to suppress the flow of the resin. It is possible to prevent the resin from flowing in the direction of gravity and becoming non-uniform without being hindered by the complicated shape.

When using a tubular dry fiber material and filling the inside with resin, it is possible to adjust the thickness of the resin in the piping system direction according to the tightening state after winding it around the pipe by appropriately determining the thickness of the tube. be.

After patching a dry fiber material that covers the damaged part and sands a resin that is about 10 times the area of the damaged part, the resin is loaded into a tubular dry fiber material with a diameter of about 3 cm, and the patched sheet is applied. Wrap the tubular dry fiber material in the same way as tying it up. The tube is deformed according to the amount of resin to be filled, but it is effective to limit the thickness of the resin to about 5 mm and to reinforce it by providing an overlap of about 1 cm when winding. When an epoxy resin is used as the resin, sufficient strength can be ensured by laminating the resins so that the thickness of the resin is about 1.5 to 2 cm. Further, when repairing a high-pressure pipe, it is also effective to reinforce the repaired part with a simple mechanical sleeve as necessary.

As a test, after artificial defects having a diameter of 5 mm were provided on a horizontal steel pipe having a diameter of 200 mm at an interval of 100 cm, the pipe was repaired by two methods as shown in FIGS. 1 and 2.

FIG. 1 shows a method according to the method of the present invention, in which polyester is used as the dry fiber material and epoxy resin is used as the resin. The patch applied to the defective portion was attached by sandwiching the resin with a thickness of 5 mm on a circular sheet having a diameter of 120 mm. In order to hold down the circular patch, a resin was loaded into a dry fiber material of the same type having a diameter of 30 mm so as to have a thickness of 5 mm when deformed. Specifically, the resin is loaded so as to have 21 to 24 CC (0.5 * 4.2 * 10 = 21) per 100 mm of the tube, held for 10 minutes, hardened to a state where it is difficult to flow, and then wound around the pipe. Reinforced. The tightening pressure is about 10 kgf in terms of tube tension, and its accuracy is not so important.

Reinforcement with a tube covered the circular patch, and reinforced in approximately three layers so that the reinforcing resin was about 15 mil meters in length up to 640 mm, which was five times the diameter of the circular sheet in the direction of the pipe axis. The first part of the reinforcement with the tube and the end part of the reinforcement were firmly tied to the repair pipe so as to be tied to the repair pipe.

On the other hand, FIG. 2 shows a general resin reinforcing method that has been conventionally performed, in which the resin is applied so as to be laminated so that the thickness of the dry resin is 15 mm, and the longitudinal direction is substantially the same as that of the method of the present invention. It was constructed so as to be 640 mm.

After the construction, 8 hours after the resin had finished curing, water was passed and pressure was applied to confirm the repair status on a trial basis. When the pressure was sequentially increased in increments of 0.01 MPa, in the conventional method shown in FIG. 2, water leakage started at 0.3 MPa, and at 0.5 MPa, a water path was formed between the resin and the pipe, causing water leakage. It occurred steadily.

In the method of FIG. 1 according to the method of the present invention, no change was observed in the repaired portion even when the pressure was increased to 1.0 MPa, and it was confirmed that there was no problem even if the pressure was maintained at the same pressure for 24 hours thereafter.

The polyester sheet having a diameter of 120 mm used for patching was prepared in advance with the shape of FIG. 3 so that the two sheets overlap each other through a protrusion having a height of 5 mm, and the flow and deformation of the sandwiching resin were suppressed. This protrusion can be replaced by a circular ring with diameters of 20, 40, 60, 80, 100 mm.

In addition, a tube made of polyester fiber material having a diameter of 30 mm used to suppress a circular patch is internally fixed with a string having a rectangular cross section of the same material having a diameter of 5 mm diagonally in the radial direction, and the resin thickness to be loaded is 5. Consideration was given so that it could easily be about millimeters.

In the above embodiment, when the tube loaded with the resin was wound, the pipe provided with the artificial defect was rotated to wind and fix the tube, and the test was conducted. At that time, in order to temporarily hold the circular patch, it was fixed by lashing with a polyester string. At the actual site, it is difficult to rotate the pipe to be repaired, so in the additional test, the tube was divided into three parts, and the start and end of winding were fixed to the pipe for each layer to be stacked in consideration of workability. The result of the test was the same as that of the above-mentioned example. In the repeated tests to obtain further reproducibility, the method of the present invention and the conventional method were changed from the series arrangement to the parallel arrangement, and the shape of the artificial defect was also expanded to 3 * 12 mm. Similar results were obtained. In addition, the test results were the same when a similar comparative test was performed by driving a cork into a 3 * 12 mm artificial defect.

It is a bird's-eye view of the Example which shows one of the best forms for carrying out this invention. It is a top view which shows the Example for carrying out this invention. It is sectional drawing which shows the Example of this invention. It is a top view at the time of carrying out an example of the conventional method under the same conditions as the method of this invention. It is sectional drawing at the time of carrying out an example of the conventional method. It is a top view of the circular patch outer sheet used in the Example of this invention method. It is a top view of the circular patch piping side sheet used in the Example of this invention method. It is sectional drawing of the circular patch outer sheet used in the Example of this invention method. It is sectional drawing of the circular patch piping side sheet used in the Example of this invention method. It is sectional drawing of the tubular fiber material used in the Example of this invention method. It is sectional drawing after the deformation of the tubular fiber material used in the Example of this invention method.

1 Steel pipe 2 Artificial defect 3 Circular sheet 4 Tube-shaped fiber 5 Resin wrapped in tubular fiber 6 Resin sandwiched between circular sheets 7 Resin 8 Ring-shaped fiber material 9 String-shaped fiber material

Claims (5)

In the repair of piping lines
When applying resin around a defect in a part of the piping line, when attaching the dry fiber material to the interior and exterior of the resin to hold and reinforce the resin, after applying the resin to the piping line side of the dry fiber material. A piping line repair method characterized by mounting. When the resin is applied to the dry fiber material, the dry fiber material is formed in a layered or tubular shape so as to wrap the resin with the dry fiber material in order to suppress the flow of the resin, and the resin and the dry reinforcing material are attached to the piping line. A method of reinforcing piping lines, which is characterized by this. 2. The described piping line repair method. In the repair of piping lines
A dry fiber material having a function of suppressing the flow of the applied resin by providing a convex portion such as a linear or lattice shape on at least one side surface of the dry fiber material in order to easily hold and reinforce the resin used for repair. .. In the repair of piping lines
In order to easily hold and reinforce the resin used for repair, the dry fiber material is configured in a tube shape, and the resin to be applied is loaded on the inner surface of the tube to suppress and hold the flow of the dry fiber material. ..

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