KR101139756B1 - An anticorrosion lining method for the inside of the welded pipe by injection of anticorrosion fiber mold. - Google Patents

Abstract

In the present invention, when connecting the water coating coating steel pipe to the buried installation, the glass cross, glass mat, etc., on the uncoated portion of the weld joint inside the pipe after welding the inside and outside of the steel pipe, a solvent-free epoxy resin two-component primer (Primer) After coating, it is impregnated with a laminated arrangement on the weld surface of the weld joint, and then a strippable rubber ring (hereinafter referred to as a "peeled rubber sheet ring") that is not bonded with a cured epoxy resin coating material is spread over the laminated coating film. Spread the support plate on it, install the contact bands at the edges of both ends of the support plate, and expand the contact band using the refracting screw jack to tighten both ends of the peeling rubber plate ring to form a sealed space. Inject the solvent-free two-component epoxy resin coating solution into the injection valve on the bottom of the exfoliation rubber plate, and exhaust the air through the upper exhaust valve. After hardening naturally in a state where the paint liquid is filled in the sealed coating space, the peeled rubber sheet ring is peeled off from the cured coating film, and the finished cured coating film with excellent flexural strength, tensile strength and impact strength is applied to the inner surface of the welded joint at the steel pipe laying site. It is about construction method to construct.

Fiber, water coated steel pipe, peeling rubber plate ring

Description

{An anticorrosion lining method for the inside of the welded pipe by injection of anticorrosion fiber mold.}

The present invention is to perform the epoxy lining reinforced with fiber (fiber) in the unpainted portion inside the weld joint for welding the steel pipe when the water coating coating steel pipe buried laying work more specifically, the steel pipe is connected welding As the coating part is damaged due to the high temperature during welding, the uncoated parts at both ends of the steel pipe are injected once to obtain a smooth cured film that is almost the same as the inner diameter of the pipe and the lining film thickness of the upper and lower parts of the pipe is uniform. It is a structure that is laminated with fiber, and it is related to the method of manufacturing lining which has excellent bending strength, tensile strength and impact strength, and excellent adhesive strength without peeling or cracking in spite of deformation caused by external pressure of pipeline or continuous vibration generated during water flow. will be.

The construction of laying steel pipe is mainly buried underground, and the length of steel pipe is about 6m in length per tube diameter, and one end of the pipe is expanded so that another connector can be inserted and processed like bell. Outside and inside are corrosion resistant, but both ends of the pipe are unpainted or shop-primer painted for welding connection. When the steel pipe is welded, it becomes a long pipe, so the inside of the pipe becomes a long cave, and it is humid, narrow, and dark. The conventional technique is to paint a paint in the form of bituminous epoxy resin paste containing an organic solvent by using a plastering knife or a spatula, or by hand painting the solvent-containing epoxy resin paint with a brush 6 to 7 times Double coating was applied to prevent corrosion. Due to the unevenness of the film thickness and the high humidity environment, this manual work causes overlapping between layers of the hardened film, which makes it difficult to achieve the purpose of preventing corrosion inside the water pipe that is constantly flooded. It has the disadvantage of shortening the life. In addition, there is a technique of an injection method using a release rubber ring as a method of eliminating such a disadvantage, but this method is the sag phenomenon caused by the load of the injection liquid injected into the release rubber plate ring, the thickness of the upper tube and the lower tube The thicknesses of the two ends are different, and the thickness of both ends of the rubber band ring is not secured, so the film thickness of both ends is extremely thin and the injection coating line is not obvious, and there is no primer coating process to reinforce adhesion. Due to the disadvantage that the interlayer peeling between the cured coating film is not good due to the lack of adhesion between the existing existing coating film and the internal coating film, if the coating film is peeled off due to the flow rate of tap water during water passage, the coating film is continuously peeled off and water is penetrated between linings and corrosion occurs. .

The tight tightening band used in the prior art has a structure in which the tightening bolts are welded to the upper band and the lower band, so that when the tight bands are pushed and inflated to each other by operating the tightening bolts, both ends of the upper and lower bands are spaced apart from each other. The tightening bolt is not close to the inner band of the steel pipe, so the more the expansion force is applied to the tighter band, the tighter the band is in close contact with the inner wall, but the back side of the tightening bolt is tighter than the upper band. The distal end of the lower band is distorted into the tube so that the release rubber plate ring between these gaps cannot be pressurized, so that the epoxy resin coating fluid leaks into this part. In order to compensate for this phenomenon, it is inconvenient to push both sides symmetrically with a separate screw jack, which causes inconvenience to communication of workers in the pipeline. In the prior art, the bitumen-based epoxy resin paste was used to fill the inner bent portion of the pipe line, and then, a glass cross mat was laminated on the paste surface, and a thin coating was applied thereon. Since it is located inside the cross-sectional inner diameter of the laminated FRP such as glass cross when the tube is deformed by the external pressure structure can not exert the tensile force, there is a disadvantage that can not express the physical strength of the fiber used.

[Patent 1] Korean Patent Publication No. 10-0005454 1977. 06. 18

[Patent 2] Korean Patent Publication 10-2005-0118430 2005. 12. 19

The present invention is to solve the problems of the prior art is that the steel pipe is welded connection ㅎ after the air is not communicated with the air, narrow, dark so that the corrosion-resistant lining work of the weld joint inside the pipeline is very coating environment As it is inadequate, there is no volatile organic solvent (VOC), the curing time of paint should be fast, and thick coating film should be completed at once, the coating thickness of the upper and lower part of the pipe should be uniform, and from the start of painting work to curing It must be installed in a protected state without being exposed to the outside. Since the solvent-free two-component epoxy resin paint injection liquid used in the present invention should not be well adhered to the exfoliated rubber plate ring, the exfoliated rubber plate ring is coated with silicone rubber or urethane rubber or teflon coated rubber or release agent that is not adhered to the epoxy resin. It is made of a material such as vulcanized rubber, and the injected epoxy hardened material is coated with a primer in order to have good adhesion with the steel surface, and the glass cross 11 or glass mat is laminated to sufficiently impregnate the epoxy primer in the fiber layer. When the hardening progresses, the peeling rubber plate ring is spread over the coating film, and a support plate is installed inside the peeling rubber plate ring. Install the contact bands on both edges of the support plate, install the refraction type screw jack on the contact band ring, and operate the screw jack nut to press the support plate and the peeling rubber plate ring to the inner wall of the tube to seal the space to inject paint. To form.

The peeling rubber sheeting ring 3 used in the present invention has a width that can sufficiently cover the welded joint, and the elastic band 12 is bonded to the inside of the diameter as shown in FIG. 3 and can maintain a constant gap at both ends of the peeling rubber sheeting ring. The support plate is made of plastic or metal plate and bent like a diameter to be divided into 2 or 4 equal parts for easy transportation in the pipeline, and the close band is connected to the upper ring 15 and the lower ring 16. Both ends are processed into concave and convex shapes (17) to engage with each other. Between the upper and lower rings, a ring for connecting the ring 14 of the refraction screw jack is welded to connect with a pin. The refraction type screw jack 5 has a structure in which one end portion thereof is connected to each other by a hinge, and the fixing plate 6 of the screw jack is formed by connecting the uneven connection portion 17 between the ring welding portions of the jacks of the upper and lower tight bands. The complex with the same force and pushing force the band close to the support plate and the peeling rubber ring is configured so that the portion of the injected liquid coating does not leak. When the installation is completed, the injection pump is connected to the injection valve 21 in the lower portion of the peeling rubber plate ring and the solvent-free two-component epoxy resin injection solution is injected. Air in the confined space is discharged through the exhaust valve on the upper part of the peeling rubber plate ring, and when the filled liquid leaks to the exhaust valve beyond the overflow tube 22 installed at the end of the exhaust valve, the injection valve is shut off. Shut off the exhaust valve and harden the injection liquid in that state. Injection epoxy resin becomes wet-on-wet type in primer and wet surface, so injection epoxy cured material has strong adhesion between steel surface and laminated FRP and injection lining, but peeling rubber plate ring is easily peeled off. As it is dismantled, it makes construction easier.

 The present invention is to solve the problems of the prior art as described above to remove the welding slag, weld spat, rust on the unpainted portion of the welded joints and surface rust harmful to the painting with an electric grinder, solvent-free two-component epoxy After the resin primer is first applied, either glass cross or glass mat is laminated on the coating film surface and the primer liquid is sufficiently impregnated to prevent the stacked glass cross or glass mat from lifting. As the coating proceeds to dryness, spread the exfoliated rubber plate ring on the laminated coating area, install the support plate inside the exfoliated rubber plate ring (3), install the adhesive band (4) at the edges of both sides of the support plate, and screw jack ring Connect the refraction type screw jack to the pin (14) and fix it with a pin on the upper lower contact band. Both ends of the peeled rubber plate ring are bonded to a band having excellent elasticity and are configured to form a gap having a predetermined thickness at the edge of the sealed space, and the support plate 9 is made of plastic or metal plate, It is bent almost equal to the inner diameter of the pipe diameter so that it is divided into 2 or 4 parts, so that it is easy to carry and assemble in a narrow pipe. The articulated screw jacks, which push the inflated bands and expand them, operate the tightening nut to push the top and bottom tight bands together, so that the tight bands between the hooks of the screw jacks are connected to the hinges of the articulated screw jacks. The fixing plate is pushed to squeeze the supporting plate and the exfoliated rubber plate ring to the pipe wall to prevent leakage of the injection liquid. The use of articulated screw jacks ensures maximum space inside the pipeline, thus facilitating operator communication and improving construction. When the adhesion is completed, the solvent-free two-component epoxy resin injection solution is injected through the injection valve at the bottom of the release rubber plate ring. When the injection liquid is filled and comes out of the overflow tube 22 inserted in the upper part of the exhaust valve, the injection valve and the exhaust valve are closed and naturally cured at room temperature. When the hardening is completed, loosen the refractive screw jack, and then disassemble it in the order of the adhesive band support plate and the peeling rubber plate ring. The method of injecting the epoxy resin coating material of the present invention is to coat the primer and the glass cross or glass mat in a wet-on-wet state where the coating is injected onto the wet film before the film is completely cured. This is how you can do it. In the structure of the curing reaction of the epoxy resin, the epoxy resin and the di-amine (Di-Amin) curing agent and a small amount of moisture present in the curing serves as a catalyst for promoting the curing, and participates in the curing reaction. However, when the primer coating film is completely cured and inactivated on the surface, the moisture on the surface inhibits adhesion between the coating layers, which causes interlayer peeling after the coating film is cured. The anti-corrosion lining constructed by the present invention is strongly adhered to the inner surface of the steel pipe while the position of the portion of the glass cross or fiber mat laminated reinforced is strongly adhered to the inner surface of the steel pipe due to the external pressure of the steel pipe. It can be prevented from cracking and peeling caused by lining even in case of frequent vibration caused by deformation and water flow.

As described above, the anti-corrosion lining constructed by the present invention maintains strong adhesion to the steel surface, the thickness of the upper lining of the welded joint and the thickness of the lower lining is kept uniform, and the release rubber plate ring is assembled by the support plate until the lining is completely cured. It can be safely installed because it is not exposed to harmful factors to the coating inside the pipeline because it keeps it safely.

A quick-drying primer of a solvent-free two-component epoxy resin is applied to the welded joint of the steel pipe with a brush or the like, and the fiber of glass cross or glass mat is laminated, and the impregnation of the primer solution is sufficient thereon, so that there is no bubble inside. A peeling rubber plate ring is arranged in the coating section of the laminated coating film, a support plate is installed inside the peeling rubber plate ring, and a close band is installed at both edges of the support plate. Connect the refraction screw jack up and down with pins to the hooks of the refraction screw jack in the contact band upper ring and the lower ring, and arrange the contact plate connected to the hinge of the refraction screw jack to push the contact part of the contact band up and down.

By manipulating the nuts in the articulated screw jacks, the upper and lower rings are pushed against each other to push the edges of the support plate and the exfoliated rubber plate ring to form an airtight space between the welded joint of the steel pipe and the exfoliated rubber plate ring and to create a coating space for the paint. The solvent-free two-component epoxy resin is injected into the paint injection pump through the injection valve on the lower part of the peeling rubber plate ring, and the fluid is filled over the overflow tube in the upper exhaust valve until the paint liquid comes out of the exhaust valve. When the injection is completed, shut off the injection valve and the exhaust valve, and naturally cure at room temperature. When the hardening of the injection solution is completed, the refractive screw jack, the contact band, the support plate, and the peeling solid plate ring are dismantled in order and the fully cured coating film is exposed.

1 is an assembled cross-sectional view for forming an injection coating space in the welded joint.

Figure 2 is a perspective view of the elastic band bonded to both edges of the peeling rubber plate ring, forming a certain thickness of the injection paint on both ends of the coating surface and serves to block the leakage of the paint with a high elastic material.

Figure 3 is an assembly plan of the concave-convex shape of both ends of the contact band and the upper lower contact band connection and the assembled view of the refractive screw jack.

Figure 4 is a cross-sectional view of the completed curing lining, the thickness of the top and bottom is uniformly formed, the surface is dense, it can be constructed with a strengthening of the adhesion to the solid stack of glass cross or glass mat.

1 is a cross-sectional view of the bell-end welding to install the felt ring on the inner surface of the welded welded steel pipe.

2 is a cross-sectional view of a felt ring installation for plain and bevel end welding of steel pipe welds.

Figure 3 is a peeled rubber plate perspective view.

Figure 4 is a detailed view of the construction section and the close contact between the band and the refractive screw jack is installed.

5 is a configuration diagram of a refractive screw jack.

6 is a completed cross-sectional view of the present invention.

<Code Description>

1. Steel pipe 2. Welded joint 3. Peeling rubber plate ring 4. Close band

5. Articulated Screw Jack 6. Screw Jack Mounting Plate

7. Hinge 8. Curing solvent-free epoxy injection 9. Support plate

10. Existing interior lining 11. Glass cross laminate

12. Elastic band 14. Pin coupling ring

15. Upper contact band 16. Lower contact band 17. Structure of upper ring and lower ring joint

18. Screw jack bolt 19. Screw jack nut 20. Screw jack body

21. Injection valve 22. Exhaust valve and overflow tube

Claims (4)

Apply a solvent-free two-component epoxy resin primer to the welded joint of the water-coated steel pipe, laminate either glass cross or glass mat, and allow the primer coating solution to be sufficiently impregnated. Spread on the primer coating, install the support plate inside the release rubber plate ring, install the lower contact band and the upper contact band at the edges of the support plate, and connect with the refractive screw jack pin to the connection of the refractive screw jack on the contact band. After fixing, operate the nut on the refraction type screw jack to push the upper contact band and the lower contact band to each other so that both ends of the support plate and the peeling rubber plate ring adhere to the steel pipe wall to form a sealed injection coating space, and the injection under the peeling rubber plate ring Connect the valve to the infusion pump to inject solvent-free two-component epoxy resin solution Inject until the overflow tube of the exhaust valve above the exfoliated rubber plate ring overflows, close the intake valve and exhaust valve, and naturally harden at room temperature. Then, remove the refractive screw jack, the adhesive band, the support plate, and the exfoliated rubber plate ring once. The anti-corrosion lining method by fiber mold injection into the inner surface of the steel pipe weld joint, characterized by completing a thick smooth lining. According to claim 1, the support plate is bent equal to the inner diameter of the pipe to be divided into two or four parts divided by plastic mold or metal plate, characterized in that the prevention of corrosion by fiber mold injection of the inner surface of the steel pipe weld joint Lining method. According to claim 1, wherein the contact band is composed of an upper band and a lower band, the end of the band is processed into an uneven shape and interlocked, and a ring for assembling a refractive screw jack is welded to the edge of the contact band. Corrosion prevention lining method by fiber mold injection into the inner surface of steel pipe welding joint. The method of claim 1, wherein the refraction screw jack is connected to the ends of the two straight screw jack by a hinge, the hinge is formed by a fixing plate for close contact with the contact band, corrosion by fiber mold injection of the inner surface of the steel pipe welding joint Prevention lining method.

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