Special anti-corrosion coating repair process for steel metal pipe

Abstract

The invention provides a special anti-corrosion coating repair process for a steel metal pipe, which relates to the technical field of pipe repair, and comprises the following steps: thoroughly derusting the surface of the repaired part of the pipe, and keeping the surface roughness; a composite adhesive is prepared, and carbon fiber cloth is soaked in the mixed composite adhesive to be fully soaked and fully distributed on the surface; carbon fiber cloth is rolled into rolls, the surfaces of the treated pipes are wrapped with the carbon fiber cloth clockwise, each roll is overlaid by 2-3 cm, and the rolls are laid flat and tensioned; carbon fiber cloth is used as a repairing material, a composite adhesive is used as a bonding material, the composite adhesive is used for dipping the carbon fiber cloth, after the repaired part of the pipe is subjected to rust removal and cleaning treatment, the carbon fiber cloth is used for carrying out clockwise and anticlockwise multi-layer bonding coating on the repaired part of the pipe, and a scraping plate and a brush are matched for scraping and surface finishing; the pipe repairing method is scientific, economical and practical, and can be operated in normal-temperature and normal-pressure states.

Description

Technical Field

[0001] The invention relates to the technical field of pipe repair, and in particular to a special anti-corrosion coating repair process for steel metal pipes. Background Art

[0002] Steel metal pipes, or steel pipes, are a type of metal material made of steel with a hollow cross-section and a length much greater than the outer diameter. They have many advantages, including high strength and hardness, the ability to withstand greater external pressure and impact, long service life, and a variety of specifications and models to meet the needs of different projects and industries. They can be connected in a variety of ways, are easy and flexible to install, and are suitable for a variety of complex environments and process requirements. As a recyclable metal material, steel pipes are conducive to environmental protection and resource conservation, and are in line with the concept of modern sustainable development.

[0003] In the use of various steel metal pipes in petroleum, chemical, metallurgical, oil field, electric power, water and other enterprises, after long-term production and operation, the pipes are prone to chemical corrosion and electrochemical corrosion due to the multiple influences of materials and environmental factors, resulting in oxidation and thinning of the pipes or even leakage, which brings serious safety hazards to production and operation, causing equipment shutdown and even causing production safety accidents. At present, most companies still use shutdown and stop operation to carry out electric welding repair or replace thinned parts. For this purpose, multiple process treatments such as unloading, purging, replacement or cleaning are required before the process can be carried out. There are many special operations involved, and the safety risks are increased. The company has a large investment in manpower, material resources and financial resources, which is time-consuming. The economic losses caused by the suspension of production cannot be underestimated. Therefore, the present invention proposes a special anti-corrosion coating repair process for steel metal pipes to solve the problems existing in the prior art. Summary of the invention

[0004] In view of the above problems, the present invention proposes a special anti-corrosion coating and repair process for steel metal pipes. The special anti-corrosion coating and repair process for steel metal pipes uses carbon fiber cloth as a repair material and a composite adhesive as a bonding material. The carbon fiber cloth is impregnated with the composite adhesive. After the repaired part of the pipe is rust-removed and cleaned, the repaired part of the pipe is coated with carbon fiber cloth in a clockwise and counterclockwise multi-layer manner. The surface is scraped flat with a scraper and a brush, and paint is used for waterproofing to achieve the purpose of pipe repair.

[0005] To achieve the purpose of the present invention, the present invention is implemented by the following technical scheme: a special anti-corrosion coating repair process for steel metal pipes, comprising the following steps:

[0006] S1: Thoroughly remove rust from the surface of the repaired part of the pipe while maintaining the roughness of the surface;

[0007] S2: prepare the composite adhesive, immerse the carbon fiber cloth into the mixed composite adhesive, make it fully impregnated and cover the surface;

[0008] S3: Roll the carbon fiber cloth into a roll, wrap it clockwise on the treated pipe surface, overlap each roll by 2-3cm, lay it flat and tighten it, and scrape off the excess composite adhesive with a scraper;

[0009] S4: Use a brush to evenly apply the composite adhesive on the surface of the carbon fiber and wait for its initial curing for 20-30 minutes;

[0010] S5: Cover the second layer of carbon fiber cloth counterclockwise, and repeat the operations of S3-S4;

[0011] S6: Use a scraper to repeatedly scrape the wrapped surface until each layer of carbon fiber cloth is fully adhered;

[0012] S7: Use a brush to paint the surface until it is flat and has no sags, and the edges are smooth and have no burrs. Wait for it to cure naturally for 48-50 hours, and then paint the surface for waterproofing.

[0013] A further improvement is that: S1 comprises the following steps:

[0014] Select rust removal equipment according to the on-site environment to remove all rust layers on the corroded parts of the pipe until there are no residual corrosion spots on the base surface;

[0015] Clean the base surface of the pipe until it is free of grease and dirt, and has no oxide layer, rust and paint coating, and maintains the required roughness;

[0016] Use a soft brush, cloth scraps, etc. to clean the dust and other impurities on the surface of the pipe to keep the surface dry and clean;

[0017] Control the air humidity on site to no more than 85% and carry out operations in this environment.

[0018] A further improvement is that in S1, rust removal is carried out by combining manual rust removal and mechanical rust removal, so that the outer surface of the steel and parts in the repaired area reaches the required quality grade, specifically: manual and mechanical St2.0 grade, spraying and projecting St3.0 grade.

[0019] A further improvement is that in S1, during the entire treatment process, the actual surface area of ​​the pipe repaired part is controlled to be 2-3 times the repair area.

[0020] A further improvement is that in S2, preparing the composite adhesive comprises the following steps:

[0021] Prepare components A and B, pour them into the container in a ratio of 1:1, and continue stirring for 1-3 minutes until the two components are fully blended and the color is uniform;

[0022] After each mixing, the carbon fiber cloth is impregnated within 20-40 minutes.

[0023] Further improvements are: the A component includes a thermoplastic resin, a plasticizer, a curing agent and a cationic surfactant, the B component includes a thermosetting resin, a modifier and a cross-linking agent, the thermoplastic resin is a mixture of one or more of polyethylene, polypropylene, nylon, and polystyrene, the thermosetting resin is a mixture of one or two of phenolic resin and epoxy resin, the plasticizer is one of phthalates and epoxy soybean oil, and the modifier is one of ACR-401, ethylene-vinyl acetate copolymer, and chlorinated polyethylene.

[0024] A further improvement is that in S2, the composite carbon fiber cloth is selected and screened based on the single fiber length of 4500-5500m.

[0025] A further improvement is that in S3, during the pipe surface coating process, the ambient temperature is controlled to be above 15°C, the steel surface temperature is controlled to be higher than the ambient temperature, a heating light source is used to increase the temperature of the pipe repair part, and the increased temperature is limited to less than 100°C.

[0026] A further improvement is that in S6, a scraper is used to repeatedly scrape and wrap the surface, and a pressure roller is used to roll the surface during the process. In S6, the standard for each layer of carbon fiber cloth to be fully attached is that the entire surface has no protrusions or bubbles.

[0027] A further improvement is that in S7, the surface is subjected to paint waterproofing treatment specifically by using the same type of paint as that on the original pipe for treatment and attaching a layer of waterproof spray coating.

[0028] The beneficial effects of the present invention are:

[0029] 1. The present invention adopts carbon fiber cloth as a repair material and a composite adhesive as a bonding material. The composite adhesive is used to impregnate the carbon fiber cloth. After the rust removal and cleaning treatment of the pipe repair part, the carbon fiber cloth is used to coat the pipe repair part in a clockwise and counterclockwise manner with multiple layers of adhesion. The scraper and brush are used to scrape the surface flat, and the paint is used for waterproofing to achieve the purpose of pipe repair. The method is scientific, economical and practical. The anti-corrosion and reinforcement can be coated at normal temperature and pressure, so that related industries and enterprises can save manpower, material and financial resources in production and operation, and improve production safety benefits.

[0030] 2. The present invention is applicable to the repair of safety hazards such as rust, thinning, and manufacturing defects in pipes and related components made of various steel metals: pig iron, cast iron, stainless steel, etc. The carbon fiber cloth and composite adhesive have excellent properties such as oil resistance, corrosion resistance, high temperature resistance, vibration resistance, and aging resistance, and are more durable. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of the present invention;

[0032] Figure 2 It is a processing schematic diagram of the present invention. DETAILED DESCRIPTION

[0033] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0034] Embodiment 1

[0035] according to Figure 1 , 2 As shown, this embodiment proposes a special anti-corrosion coating repair process for steel metal pipes, comprising the following steps:

[0036] S1: Thoroughly remove rust from the surface of the repaired part of the pipe, while keeping the surface rough; specifically including the following steps: select rust removal equipment according to the on-site environment, remove all rust layers from the rusted parts of the pipe until there are no residual corrosion points on the base surface; clean the base surface of the pipe until there is no grease and dirt, no oxide layer, rust and paint coating attachments, and maintain the required roughness; use a soft brush, cloth scraps, etc. to clean the dust and other impurities on the surface of the pipe, keep the surface dry and clean; control the on-site air humidity to no more than 85%, and operate in this environment. Rust removal is carried out by combining manual rust removal and mechanical rust removal, so that the outer surface of the steel and components of the repaired part reaches the required quality grade, specifically: manual mechanical St2.0 grade, spraying and projectile St3.0 grade. During the entire treatment process, the actual surface treatment area of ​​the pipe repair part is controlled to be 2-3 times the repair area.

[0037] S2: Prepare the composite adhesive, immerse the carbon fiber cloth in the mixed composite adhesive, make it fully impregnated and cover the surface; prepare the composite adhesive including the following steps: prepare component A and component B, pour A and B into the container in a ratio of 1:1, and continue stirring for 1-3 minutes until the two components are fully blended and the color is uniform; after each preparation, immerse the carbon fiber cloth within 20-40 minutes. The component A includes a thermoplastic resin, a plasticizer, a curing agent and a cationic surfactant, and the component B includes a thermosetting resin, a modifier and a cross-linking agent. The thermoplastic resin is a mixture of one or more of polyethylene, polypropylene, nylon, and polystyrene. The thermosetting resin is a mixture of one or two of phenolic resin and epoxy resin. The plasticizer is one of phthalates and epoxy soybean oil. The modifier is one of ACR-401, ethylene-vinyl acetate copolymer, and chlorinated polyethylene. Select the composite carbon fiber cloth and screen it with the single fiber length reaching 4500-5500m as the selection standard.

[0038] S3: Roll the carbon fiber cloth into a roll, wrap it clockwise on the treated pipe surface, overlap each roll by 2-3cm, flatten and tighten, and scrape off the excess composite adhesive with a scraper; during the pipe surface coating process, control the ambient temperature above 15℃, control the steel surface temperature higher than the ambient temperature, use a heating light source to increase the temperature of the pipe repair part, and limit the increased temperature to less than 100℃.

[0039] S4: Use a brush to evenly apply the composite adhesive on the surface of the carbon fiber and wait for its initial curing for 20-30 minutes.

[0040] S5: Cover the second layer of carbon fiber cloth counterclockwise, and repeat the operations of S3-S4.

[0041] S6: Use a scraper to repeatedly scrape the surface until each layer of carbon fiber cloth is fully attached. Use a scraper to repeatedly scrape the surface, and use a pressure roller to roll the surface during the process. The standard for each layer of carbon fiber cloth to be fully attached is: there is no protrusion or bubble on the overall surface.

[0042] S7: Use a brush to paint the surface until it is flat and has no sags, and the edges are smooth and have no burrs. Wait for it to cure naturally for 48-50 hours, and then paint the surface for waterproofing. Specifically: Use the same paint as the original pipe for treatment, and attach a layer of waterproof spray coating.

[0043] Carbon fiber cloth is used as the repair material, composite adhesive is used as the bonding material, and the carbon fiber cloth is impregnated with the composite adhesive. After the rust removal and cleaning of the pipe repair part, the carbon fiber cloth is used to coat the pipe repair part in multiple layers in a clockwise and counterclockwise direction. The scraper and brush are used to scrape the surface flat, and the paint is used for waterproofing to achieve the purpose of pipe repair. This is scientific, economical and practical, and can be coated for anti-corrosion reinforcement at normal temperature and pressure.

[0044] Embodiment 2

[0045] according to Figure 1 , 2 As shown, this embodiment proposes a special anti-corrosion coating repair process for steel metal pipes, comprising the following steps:

[0046] Select Materials

[0047] Carbon fiber cloth has excellent performance. It uses high-quality aviation-grade carbon filaments. The length of a single filament can reach 5,000 meters, ensuring the continuity of the carbon fiber cloth without broken filaments. The tension is constant, the discreteness is small, the strength is high, and the inspection pass rate is 100%. The carbon fiber cloth is woven evenly and has good flatness. It is moderately soft and easy to stick. It has good adaptability to special composite adhesives, is easy to infiltrate, and has a low hollowing rate. It has light weight and can be operated in a small space. The normal use of the original equipment is not affected during construction. It has high strength and can be flexibly used for compression, bending and shear reinforcement. It is flexible and can wrap pipes with complex shapes. It can be freely cut, overlapped and bonded, and can be extended at will, which is convenient for construction. It can withstand chemical corrosion and harsh environments such as acids, alkalis, and salts, is pollution-free, and is suitable for reinforcement of the surfaces of various steel and metal pipe components.

[0048] High-performance polymer fiber composite adhesive: good wettability, can effectively impregnate carbon fiber cloth, has certain thixotropic properties, and is convenient for construction; has good compatibility with carbon fiber cloth; is resistant to oil, acid and alkali corrosion, moisture and heat aging, and long-term stress; after curing, the adhesive layer has excellent physical and mechanical properties, is strong and has a certain elasticity.

[0049] Surface rust removal

[0050] To achieve a good repair effect, the surface of the repaired part must first be thoroughly derusted, and at the same time, the surface must have a certain degree of roughness. The rust removal method is manual and mechanical, so that the outer surface of the steel and components of the repaired part can reach the required quality grade (manual and mechanical St2.0 grade, spraying and projecting St3.0 grade).

[0051] Rust removal: select appropriate operating tools according to the on-site environment to completely remove the rust layer at the rusted area, leaving no residual corrosion spots on the base surface;

[0052] The base surface of the pipe should be free of grease and dirt, and no attachments such as oxide layer, rust and paint coating, and the repaired surface should maintain a certain roughness.

[0053] Use a soft brush, cloth scraps, etc. to clean the surface dust and other impurities to ensure that the surface is dry and clean.

[0054] Whether manual or mechanical rust removal, the air humidity on site should not be greater than 85%, and outdoor rust removal should not be carried out on rainy days;

[0055] Coating reinforcement

[0056] Before repair, make sure that pipes and other equipment and facilities are not under pressure and that the surface is clean and dry;

[0057] The composite adhesive is composed of components A and B. Pour A and B into the container in the corresponding proportion and stir continuously for 1-3 minutes until the two components are fully blended and the color is uniform.

[0058] Dipping the carbon fiber cloth into the mixed composite adhesive to fully impregnate it and cover the entire surface;

[0059] Use tools to roll the carbon fiber cloth into a roll, wrap it clockwise to the treated surface, overlap each roll by 2-3cm, lay it flat and tighten it, and scrape off the excess adhesive with a scraper;

[0060] Use a brush to evenly apply the adhesive on the surface of the carbon fiber and wait for its initial curing for 20 to 30 minutes;

[0061] Cover the second side counterclockwise and repeat the previous exercise;

[0062] Use a scraper to repeatedly scrape the surface. Each layer of carbon fiber cloth should fully fit the substrate without protrusions or bubbles.

[0063] Use a brush to paint the surface to make it smooth without sagging, and the edges smooth without burrs;

[0064] After reinforcement is completed, wait for it to cure naturally for 48 hours to reach the best condition;

[0065] The surface is treated with paint for waterproofing, and priority is given to using the same type of paint as used on the original equipment (two primers, one intermediate and two topcoats: two sides of epoxy zinc-rich primer, one side of epoxy micaceous iron intermediate paint, and two sides of acrylic polyurethane topcoat).

[0066] The actual surface treatment area of ​​the repaired part is 2-3 times the repaired area, so that the bonding contact surface between the composite material and the matrix is ​​larger, effectively strengthening the pressure tolerance of the weak part;

[0067] After the two-component adhesive is mixed at room temperature, the operating time is 20-40 minutes. It will gradually solidify and harden over time. Therefore, it is recommended to mix according to the actual situation, in small amounts and multiple times, to reduce waste.

[0068] During the pipe surface coating process, the ambient temperature must be controlled above 10°C (preferably above 15°C) so that the construction can proceed normally. The steel surface temperature must be higher than this limit to ensure the normal performance of the composite material.

[0069] When safety conditions permit, increase the temperature of the repaired part of the steel metal pipe, such as using a heating light source, but the temperature should not exceed 100°C, and it should not be heated directly with open flames (determined according to the specific conditions such as the construction site environment and safety requirements).

[0070] During the construction process, humidity affects the curing speed. Choose to construct in sunny weather with humidity less than 85% to ensure the quality of reinforcement.

[0071] The special anti-corrosion coating and repair process for steel metal pipes adopts carbon fiber cloth as a repair material and a composite adhesive as a bonding material. The composite adhesive is used to impregnate the carbon fiber cloth. After the rust removal and cleaning treatment of the pipe repair part, the carbon fiber cloth is used to perform multi-layer clockwise and counterclockwise bonding and coating on the pipe repair part. The scraper and the brush are used to scrape the surface flat, and the paint is used for waterproofing to achieve the purpose of pipe repair. The process is scientific, economical and practical. The anti-corrosion coating and reinforcement can be performed at room temperature and pressure, so that related industries and enterprises can save manpower, material and financial resources in production and operation, and improve safety production benefits. The present invention is suitable for the repair of safety hazards such as rust thinning, manufacturing defects and the like of pipes and related components made of various steel metals: pig iron, cast iron, stainless steel, etc. The carbon fiber cloth and the composite adhesive have excellent properties such as oil resistance, corrosion resistance, high temperature resistance, vibration resistance, aging resistance and the like, and are more durable.

[0072] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A special anti-corrosion coating repair process for steel metal pipes, characterized in that: The following steps are involved: S1: Thoroughly remove rust from the surface of the repaired part of the pipe while maintaining the roughness of the surface; S2: prepare the composite adhesive, immerse the carbon fiber cloth into the mixed composite adhesive, make it fully impregnated and cover the surface; S3: Roll the carbon fiber cloth into a roll, wrap it clockwise on the treated pipe surface, overlap each roll by 2-3cm, lay it flat and tighten it, and scrape off the excess composite adhesive with a scraper; S4: Use a brush to evenly apply the composite adhesive on the surface of the carbon fiber and wait for its initial curing for 20-30 minutes; S5: Cover the second layer of carbon fiber cloth counterclockwise, and repeat the operations of S3-S4; S6: Use a scraper to repeatedly scrape the wrapped surface until each layer of carbon fiber cloth is fully adhered; S7: Use a brush to paint the surface until it is flat and has no sags, and the edges are smooth and have no burrs. Wait for it to cure naturally for 48-50 hours, and then paint the surface for waterproofing.

2. A special anti-corrosion coating and repair process for steel metal pipes according to claim 1, characterized in that: The S1 comprises the following steps: Select rust removal equipment according to the on-site environment to remove all rust layers on the corroded parts of the pipe until there are no residual corrosion spots on the base surface; Clean the base surface of the pipe until it is free of grease and dirt, and has no oxide layer, rust and paint coating, and maintains the required roughness; Use a soft brush, cloth scraps, etc. to clean the dust and other impurities on the surface of the pipe to keep the surface dry and clean; Control the air humidity on site to no more than 85% and carry out operations in this environment.

3. A special anti-corrosion coating and repair process for steel metal pipes according to claim 2, characterized in that: In S1, rust removal is carried out by combining manual rust removal and mechanical rust removal, so that the steel and the outer surface of the parts at the repaired part can reach the required quality grade, specifically: manual and mechanical St2.0 grade, spraying and projecting St3.0 grade.

4. A special anti-corrosion coating and repair process for steel metal pipes according to claim 3, characterized in that: In S1, during the entire treatment process, the actual surface area of ​​the pipe repaired part is controlled to be 2-3 times the repaired area.

5. A special anti-corrosion coating and repair process for steel metal pipes according to claim 1, characterized in that: In S2, preparing the composite adhesive comprises the following steps: Prepare components A and B, pour them into the container in a ratio of 1:1, and continue stirring for 1-3 minutes until the two components are fully blended and the color is uniform; After each mixing, the carbon fiber cloth is impregnated within 20-40 minutes.

6. A special anti-corrosion coating and repair process for steel metal pipes according to claim 5, characterized in that: The component A includes a thermoplastic resin, a plasticizer, a curing agent and a cationic surfactant, the component B includes a thermosetting resin, a modifier and a cross-linking agent, the thermoplastic resin is a mixture of one or more of polyethylene, polypropylene, nylon, and polystyrene, the thermosetting resin is a mixture of one or two of phenolic resin and epoxy resin, the plasticizer is one of phthalates and epoxy soybean oil, and the modifier is one of ACR-401, ethylene-vinyl acetate copolymer, and chlorinated polyethylene.

7. A special anti-corrosion coating and repair process for steel metal pipes according to claim 6, characterized in that: In S2, composite carbon fiber cloth is selected and screened based on the single fiber length of 4500-5500m.

8. The special anti-corrosion coating and repair process for steel metal pipes according to claim 1 is characterized in that: In S3, during the tube surface coating process, the ambient temperature is controlled to be above 15°C, the steel surface temperature is controlled to be higher than the ambient temperature, a heating light source is used to increase the temperature of the repaired part of the tube, and the increased temperature is limited to less than 100°C.

9. A special anti-corrosion coating and repair process for steel metal pipes according to claim 1, characterized in that: In S6, the scraper is used to repeatedly scrape and wrap the surface, and the pressure roller is used to roll the surface during the process. In S6, the standard for each layer of carbon fiber cloth to be fully attached is: there is no protrusion or bubble on the entire surface.

10. A special anti-corrosion coating and repair process for steel metal pipes according to claim 1, characterized in that: In S7, the surface is subjected to paint waterproofing treatment specifically by using the same type of paint as that on the original pipe for treatment and attaching a layer of waterproof spray coating.

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