GRP pipeline maintenance method

Abstract

The invention relates to the technical field of GRP pipeline maintenance and repair, in particular to a GRP pipeline maintenance method which comprises the following steps: judging the pathogenesis type of a to-be-maintained GRP pipeline, and if the to-be-maintained GRP pipeline is a class-A pathogenesis, using a first maintenance method; comprising the following steps that S1-1, a defect area of a to-be-maintained GRP pipeline is polished, the polished area at least extends out of the defect area by 45 mm-55 mm, a plurality of first patch layers are cut, and each first patch layer comprises glass fiber fine felt cloth and glass fiber coarse gauze which are used for lamination; s1-2, the polishing area is coated with resin, and the first patch layer is placed on the coated resin; s1-3, rolling is conducted on each first patch layer, so that each first patch layer is completely soaked with the resin; and S1-4, the first patch layer is solidified and ground, so that the ground area is flush with the periphery of the pipeline. According to the method, the pipeline does not need to be directly cut or replaced, only the damaged area is repaired, the maintenance time is shortened, the construction efficiency is improved, and the construction cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of GRP pipeline maintenance and repair, and in particular to a GRP pipeline repair method. Background Art

[0002] GRP pipes (GRP pipes, also known as polyester GRP pipes) can be manufactured with a large diameter, up to 4m, which can meet the needs of water supply and drainage pipeline projects under large flow rates; they can resist the erosion of acids, salts, seawater, corrosive soil or groundwater and many chemical fluids, and have good corrosion resistance, excellent mechanical properties, high pipe wall strength, good heat and frost resistance, low specific gravity, easy transportation, convenient installation and other advantages. They are currently widely used in water supply and drainage project construction.

[0003] When building a factory on the coast, it is often necessary to lay GRP pipes in the water, underwater or on land areas for drainage. During construction, thousands of GRP pipes are often installed and connected. Since GRP pipes are produced using a fiber winding process and are chemical building material pipes, they are easily damaged when affected by external forces.

[0004] During transportation and installation, GRP pipes may be damaged due to improper collisions, bumps, pressure or abnormal human operations. When existing GRP pipes are damaged, they are often cut or replaced directly, which is not only time-consuming and labor-intensive, but also significantly increases construction costs. Therefore, it is urgent to develop a method for repairing damaged GRP pipes to save manpower, financial resources and time costs, avoid wasting construction materials, and create higher benefits for the project. Summary of the invention

[0005] The purpose of the present invention is to provide a GRP pipeline repair method to overcome the shortcomings of the prior art that damaged GRP pipelines can only be cut or replaced, which affects construction efficiency and increases construction costs.

[0006] In a first aspect, the present invention provides a GRP pipe repair method, comprising the following steps:

[0007] Determine the cause type of the GRP pipe to be repaired, the cause type includes Class A causes; if the GRP pipe to be repaired is Class A causes, use the first repair method; Class A causes include: at least one of pipe surface cracks, pipe surface bulges, pipe surface indentations, pipe surface white spots, and pipe inner lining or surface layer loss; the first repair method includes the following steps:

[0008] S1-1: Grind the defective area of ​​the GRP pipe to be repaired, the grinding area extends at least 45mm-55mm beyond the defective area, cut multiple first patch layers, the first patch layer includes glass fiber fine felt cloth and glass fiber coarse yarn cloth used for lamination;

[0009] S1-2: Apply resin to the polished area and place the first patch layer on the applied resin;

[0010] S1-3: Rolling each first patch layer to make each first patch layer completely soaked with resin;

[0011] S1-4: Curing and grinding the first patch layer to make the ground area flush with the surface of the non-ground area around the pipe.

[0012] The GRP pipeline repair method provided by the present invention provides a repair method for Class A causes without directly cutting or replacing the GRP pipeline to be repaired. Compared with directly cutting or replacing the entire pipeline, this method only repairs the damaged area. This greatly shortens the repair time, improves construction efficiency, and reduces construction costs; the method avoids cutting the pipeline over a large area and maintains the overall structural integrity of the pipeline. The method uses a first patch layer, and the polishing area used for repair only occupies a small part of the pipeline area, which is conducive to extending the service life of the pipeline; by rolling each first patch layer, the air trapped between layers can be well removed, thereby improving the reliability of repair.

[0013] Preferably, the cause type also includes a Class B cause. If the GRP pipeline to be repaired has a Class B cause, the second repair method is used;

[0014] Category B causes include at least one of the following: pits on the pipe surface, pores on the pipe surface, protruding glass fibers on the pipe surface, protruding resin blocks on the pipe surface, wrinkles on the pipe surface, and scratches on the pipe surface;

[0015] The second maintenance method includes the following steps:

[0016] S2-1: Grind the defective area of ​​the GRP pipe to be repaired, the grinding area extends at least 45mm-55mm beyond the defective area, and cut the second patch layer, which includes a glass fiber surface felt;

[0017] S2-2: coating resin on the polished area, placing the second patch layer on the coated resin, and coating the second patch layer with resin so that the second patch layer is completely soaked with the resin;

[0018] S2-3: The second patch layer is cured and ground so that the ground area is flush with the surface of the non-ground area around the pipe.

[0019] Furthermore, the GRP pipeline repair method provided by the present invention also provides a second repair method for type B causes, which classifies and processes different causes according to the types of causes, thereby ensuring that each cause receives the most suitable repair, thereby improving the repair efficiency and repair quality and saving the repair cost.

[0020] Preferably, the cause type also includes a C-type cause. If the GRP pipeline to be repaired has a C-type cause, the third repair method is used;

[0021] Category C causes include: pipe leakage;

[0022] The third maintenance method includes the following steps:

[0023] If there are multiple leakages in the GRP pipe to be repaired and there is no structural damage to the GRP pipe to be repaired, and the leakage disappears after the pressure of the GRP pipe to be repaired is reduced to 2 bar, the GRP pipe to be repaired will be downgraded to a pressure-free pipe used only for gravity flow and no further repair is required; if the leakage does not disappear after the pressure of the GRP pipe to be repaired is reduced to 2 bar, the GRP pipe to be repaired will be scrapped and no further repair will be carried out; if there is only one leakage in the GRP pipe to be repaired after the pressure of the GRP pipe to be repaired is reduced to 2 bar, and there is no structural damage to the GRP pipe to be repaired, the defective area of ​​the GRP pipe to be repaired will be polished, the third patch layer will be cut, resin will be coated on the polished area, and the third patch layer will be placed on the coated resin so that the third patch layer is completely soaked with resin; the first sealing layer is used to seal the defective area from the inside of the pipe, the first sealing layer includes glass fiber fine felt cloth and glass fiber surface felt used for lamination, and the first sealing layer extends at least 150mm outside the defective area; the third patch layer includes 430~470g / m 2 Glass fiber felt cloth and 800~840g / m 2 Glass fiber roving cloth, preferably 450g / m 2 Glass fiber felt cloth and 820g / m 2 Glass fiber roving cloth, the side length of the third patch layer shall not be less than 250mm;

[0024] If the GRP pipe to be repaired has only a small leakage but the source of the leakage cannot be determined, and the pipe has no structural damage, grind the defective area of ​​the GRP pipe to be repaired along the circumference of the pipe and extend it to a circle around the pipe, apply resin to the grinded area, use the first wrapping layer to completely wrap the defective area along the circumference of the pipe, and apply resin to the first wrapping layer so that the first wrapping layer is completely soaked with resin; use the second sealing layer to seal the defective area from the inside of the pipe, the second sealing layer includes glass fiber fine felt cloth and glass fiber surface felt used for lamination, and the second sealing layer extends at least 150mm outside the defective area; the first wrapping layer includes 430~470g / m 2 Glass fiber felt cloth and 800~840g / m 2 Glass fiber roving cloth, preferably 450g / m 2 Glass fiber felt cloth and 820g / m 2 Fiberglass roving.

[0025] Furthermore, the GRP pipe repair method provided by the present invention also provides a third repair method for type C causes. The third repair method subdivides the leakage problem into multi-point leakage and single-point leakage, and adopts different treatment methods according to the specific situation, which reflects a high degree of pertinence and higher construction efficiency. For pipes with slight multi-point leakage, after meeting specific requirements, they can be downgraded to a pressure-free pipe used only for gravity flow, avoiding unnecessary scrapping and improving resource utilization. For single-point leakage, a combined internal and external repair method (external patch + internal seal) is adopted, which greatly improves the reliability of the repair. For situations where the source of the leakage cannot be determined, a full-circle wrapping method is adopted to ensure comprehensive repair. The laminated use of glass fiber felt cloth and glass fiber roving cloth enhances the overall strength of the patch, and the combination of the two can provide excellent mechanical properties in all directions; the side length of the third patch layer is set to be no less than 250mm, which ensures that the patch can completely cover the damaged area and its surroundings, providing sufficient safety margin for repair, and the sealing layer extends at least 150mm beyond the defective area to ensure complete sealing; the external patch and the internal sealing layer work together to form a powerful dual protection system, which repairs from both inside and outside the pipeline, greatly improving the reliability and durability of the repair. Sufficient coverage and extension help maintain long-term repair effects and reduce future maintenance needs.

[0026] Preferably, the cause type also includes a Class D cause. If the GRP pipeline to be repaired has a Class D cause, the fourth repair method is used;

[0027] Category D causes include: pipeline delamination;

[0028] The fourth maintenance method comprises the following steps:

[0029] Assess the degree of pipeline delamination;

[0030] If only the surface of the GRP pipe to be repaired is delaminated, grind off the delaminated area, remove the dust, apply resin to the polished area, cure it, and grind it to make the polished area flush with the non-polished area around the GRP pipe to be repaired;

[0031] If the delaminated area penetrates deep into the GRP pipe lining to be repaired, grind off the delaminated area, apply resin on the polished area, lay the fourth patch layer on the coated resin so that the fourth patch layer is completely soaked with resin, and finally cure and grind to make the polished area flush with the non-polished area around the pipe; the fourth patch layer includes 430~470g / m 2 Glass fiber mat, preferably 450g / m 2 Fiberglass Felt.

[0032] Furthermore, the GRP pipe repair method provided by the present invention also provides a fourth repair method for Class D causes. Different treatment methods are adopted according to the different degrees of stratification (surface stratification and deep lining stratification), so as to achieve accurate repair of Class D causes. For slight surface stratification, a simple grinding and resin coating method is adopted to avoid excessive repair and save materials and time. For stratification deep into the lining, a more comprehensive repair method is adopted to ensure the thoroughness and reliability of the repair.

[0033] Preferably, the cause type also includes a type E cause. If the GRP pipeline to be repaired has a type E cause, the fifth repair method is used;

[0034] Category E causes include: damage to the outer layer of the pipe;

[0035] The fifth maintenance method includes the following steps:

[0036] Determine the type of GRP pipe to be repaired;

[0037] If the GRP pipe to be repaired is a non-pressure pipe used only for gravity flow: grind the defective area of ​​the GRP pipe to be repaired, apply resin on the grinded area, use the fifth patch layer to fill the damaged area, and continue to use the fifth patch layer to cover the entire grinded area after the damaged area is filled. The diameter of the grinded area is at least four times the thickness of the fifth patch layer used to fill the damaged area. Apply resin on the fifth patch layer so that the fifth patch layer is completely soaked with resin. Curing and grinding the fifth patch layer so that the grinded area is flush with the non-grinded area around the pipe. The fifth patch layer includes glass fiber felt cloth and glass fiber roving cloth used for lamination. The first and last layers of the fifth patch layer are both glass fiber felt cloth.

[0038] If the GRP pipe to be repaired is a pressurized pipe: grind the defective area of ​​the GRP pipe to be repaired along the circumference of the pipe and extend it to one circle of the pipe, apply resin on the grinded area, use the second wrapping layer to fill the damaged area, and continue to use the second wrapping layer to cover the entire grinded area after the damaged area is filled. The extending length of the grinded area in the axial direction of the pipe is at least four times the thickness of the second wrapping layer filling the damaged area. Resin is applied to the second wrapping layer so that the second wrapping layer is completely soaked with resin. The second wrapping layer includes glass fiber felt cloth and glass fiber roving cloth used for lamination, and the first layer and the last layer of the second wrapping layer are both glass fiber felt cloth.

[0039] Furthermore, the GRP pipeline repair method provided by the present invention also provides a fifth repair method for Class E causes. Different repair methods are used according to whether the pipeline is a non-pressure pipeline used only for gravity flow or a pressurized pipeline, so as to achieve accurate repair of Class E causes; the size of the grinding area is associated with the filling thickness (for example, at least four times the filling thickness), ensuring sufficient repair area and improving the reliability of the repair. The full-circle wrapping method is used for pressurized pipelines to ensure the comprehensiveness and safety of the repair and meet the special requirements of pressurized pipelines.

[0040] Preferably, the first layer and the last layer of the third patch layer are both glass fiber felt cloth.

[0041] With this setting, the first and last layers of the third patch layer are designed as glass fiber felt cloth. This design enhances the overall strength and toughness of the patch layer, ensuring that the repair area can better resist external impact and internal pressure changes. At the same time, the glass fiber felt cloth has a tight structure and even fiber distribution, which can effectively fill the tiny pores on the surface, improve the sealing of the repair area, and prevent further leakage. In addition, the felt cloth also has good resin adsorption and penetration properties, which helps the resin to be evenly distributed in the patch layer, thereby enhancing the overall structural stability and durability of the patch layer.

[0042] Preferably, when the pressure of the GRP pipe to be repaired is 6 Bar, the number of layers of the third patch layer is three; when the pressure of the GRP pipe to be repaired is 9-12 Bar, the number of layers of the third patch layer is five; when the pressure of the GRP pipe to be repaired is 15-16 Bar, the number of layers of the third patch layer is seven.

[0043] This design ensures that the repaired pipeline can maintain sufficient strength and sealing under different pressures, avoiding the risk of pipeline damage or leakage under high pressure conditions.

[0044] Preferably, the first layer and the last layer of the first wrapping layer are both glass fiber mat cloth.

[0045] Preferably, when the pressure of the GRP pipe to be repaired is 6 Bar, the number of layers of the first wrapping layer is three; when the pressure of the GRP pipe to be repaired is 9-12 Bar, the number of layers of the first wrapping layer is five; when the pressure of the GRP pipe to be repaired is 15-16 Bar, the number of layers of the first wrapping layer is seven.

[0046] Preferably, if the repair area of ​​the GRP pipe to be repaired exceeds 5% of the inner surface or outer surface area of ​​the GRP pipe to be repaired, no further repair is performed; and the number of repairs within one meter of the axial direction of the GRP pipe to be repaired does not exceed one time.

[0047] This restrictive design ensures the locality of pipeline repair and avoids the impact of excessive repair on the overall structure of the pipeline. It also ensures the strength and durability of the repair area and maintains the overall performance of the pipeline.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] 1. The GRP pipe repair method provided by the present invention provides a repair method for Class A causes without directly cutting or replacing the GRP pipe to be repaired. Compared with directly cutting or replacing the entire pipe section, this method only repairs the damaged area. This greatly shortens the repair time, improves the construction efficiency, and reduces the construction cost;

[0050] 2. The GRP pipeline repair method provided by the present invention avoids cutting the pipeline in a large area and maintains the overall structural integrity of the pipeline. The method uses the first patch layer, and the polishing area used for repair only occupies a small part of the pipeline area, which is conducive to extending the service life of the pipeline;

[0051] 3. The GRP pipe repair method provided by the present invention can effectively remove the air trapped between layers by rolling the first patch layer of each layer, thereby improving the repair reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 Flow chart of GRP pipe maintenance method.

[0053] Figure 2 This is a schematic diagram of a GRP pipe with multiple leakage points.

[0054] Figure 3 This is a schematic diagram of a GRP pipe with only a small leak.

[0055] Markings in the figure:

[0056] 1- Leakage point. DETAILED DESCRIPTION

[0057] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0058] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all based on the expression of the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0059] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0060] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0061] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0062] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0063] Example 1

[0064] like Figure 1 As shown, this embodiment provides a GRP pipe repair method for repairing GRP pipes (glass fiber reinforced plastic pipes, also known as polyester glass fiber reinforced plastic pipes) damaged during transportation and installation. The GRP pipes in this embodiment are GRP pipes conventionally used in industrial production. The GRP pipes generally include an inner lining layer, a reinforcement layer, and an outer layer from the inside to the outside.

[0065] When using the GRP pipe repair method provided in this embodiment, the repair area of ​​the GRP pipe to be repaired does not exceed 5% of the inner surface or outer surface area of ​​the GRP pipe to be repaired. If the repair area of ​​the GRP pipe to be repaired exceeds 5% of the inner surface or outer surface area of ​​the GRP pipe to be repaired, no repair is performed, and the defective pipe part is directly cut or the pipe is abandoned. If the number of repairs within one meter of the axial direction of the GRP pipe to be repaired is more than one (not including one time), no repair is performed, and the defective pipe part is directly cut or the pipe is abandoned.

[0066] The GRP pipeline maintenance method provided in this embodiment comprises the following steps:

[0067] First, the cause type of the GRP pipe to be repaired is determined, and the cause type of the GRP pipe to be repaired may include type A. If the GRP pipe to be repaired is of type A, the first repair method is used.

[0068] In this embodiment, the Class A causes include at least one of pipeline surface cracks, pipeline surface bulges, pipeline surface indentations, pipeline surface white spots, and pipeline lining or surface layer loss:

[0069] Pipe surface cracks: For example, axial or circumferential cracks, star-shaped cracks, radial cracks, etc. appear on the inner and / or outer surfaces of the GRP pipe;

[0070] Pipe surface bulge: For example, bulges appear on the inner and / or outer surfaces of GRP pipes. If there is only a single bulge, the diameter of the bulge is greater than 10mm, or every 0.1m 2 If there are more than four bulges and the diameter of the bulge is ≤10mm, the first repair method can be used for repair. The color of the bulge is lighter than the surrounding pipe surface, and there is air trapped in the bulge.

[0071] Pipe surface indentations: For example, if spiral or strip-shaped indentations appear on the inner and / or outer surfaces of GRP pipes, the depth of the indentations is between 0mm and 3mm, and the depth of the indentations exceeds one-third of the nominal thickness, the first repair method can be used for repair;

[0072] White spots on the pipe surface: For example, small or large white spots appear on the inner and / or outer surface of the GRP pipe due to water droplets;

[0073] Pipe lining or surface layer missing: For example, the lining of a GRP pipe is missing 0-14%, and the surface layer is missing 0-35%.

[0074] The first maintenance method provided in this embodiment includes the following steps:

[0075] S1-1: The defective area of ​​the GRP pipe to be repaired can be cleaned with an appropriate solvent or detergent to ensure that the surface is dry and free of dust and grease; the defective area of ​​the GRP pipe to be repaired is polished with a polishing device (such as sandpaper or a scraper) to polish off the defects and ensure that the surface of the polished area is flat; the polished area extends at least 45mm-55mm beyond the defective area, and the first patch layer is cut according to the size of the polished area. The first patch layer includes glass fiber fine felt cloth and glass fiber roving for lamination. In this embodiment or other embodiments, the glass fiber fine felt cloth and glass fiber roving cloth can be alternately laminated; in this embodiment or other embodiments, the glass fiber roving cloth can use the glass fiber roving cloth specified in "Glass Fiber Untwisted Roving Cloth" (GB / T18370-2014); the glass fiber fine felt cloth is a felt cloth formed by cutting a glass fiber raw silk cake (untwisted roving is also acceptable) into 50mm long raw silk by a cutter and settling it randomly and disorderly on a stainless steel mesh belt.

[0076] S1-2: Apply resin to the polished area. The resin in this embodiment may be polyester resin or epoxy resin. The resin may be mixed with aluminum hydroxide reinforcing agent and accelerator to form a paste. The resin may completely soak the polished area. Place the first patch layer on the applied resin. Note that the area outside the polished area may not be coated with resin.

[0077] S1-3: Use an aluminum roller to roll each first patch layer to ensure that each first patch layer is wetted by the roller and each first patch layer is completely soaked with the resin;

[0078] In this embodiment, after the first patch layer is laid, a layer of glass fiber surface felt may be laid;

[0079] S1-4: Cure the first patch layer and the fiberglass surface felt at room temperature. You can also use an infrared oven or other device to increase the temperature to cure the first patch layer and the fiberglass surface felt. Wait until the first patch layer and the fiberglass surface felt are completely cured, and use sandpaper or a grinding wheel to grind and polish to make the polished area flush with the non-polished area around the pipe.

[0080] The GRP pipe repair method provided in this embodiment provides a repair method for Class A causes without directly cutting or replacing the GRP pipe to be repaired. Compared with directly cutting or replacing the entire pipe section, this method only repairs the damaged area. This greatly shortens the repair time, improves construction efficiency, and reduces construction costs; this method avoids cutting a large area of ​​the pipe and maintains the overall structural integrity of the pipe. This method uses a first patch layer, and the polishing area used for repair only occupies a small part of the pipe area, which is conducive to extending the service life of the pipe; by rolling each first patch layer, the air trapped between layers can be well removed, improving the reliability of repair.

[0081] Example 2

[0082] Based on Example 1, the GRP pipeline maintenance method provided in this embodiment includes the following steps:

[0083] First, the cause type of the GRP pipe to be repaired is determined. The cause type of the GRP pipe to be repaired may include a Class B cause. If the GRP pipe to be repaired is a Class B cause, the second repair method is used.

[0084] In this embodiment, the Class B cause includes at least one of the following: pits on the pipeline surface, pores on the pipeline surface, protruding glass fibers on the pipeline surface, protruding resin blocks on the pipeline surface, wrinkles on the pipeline surface, and scratches on the pipeline surface:

[0085] Pipe surface pits: For example, the inner and / or outer surfaces of GRP pipes have inwardly sunken pits, the diameter of the pits is generally greater than 1.5 mm, and the depth of the pits is generally greater than 1.5 mm;

[0086] There are pores on the pipe surface: For example, the inner and / or outer surfaces of the GRP pipe have visible small pores or gaps, which can be broken with sharp objects such as scissors; if there is only a single pore, the pore diameter is greater than 15mm and the pore depth is greater than 1.5mm; or every 0.1m 2 If there are more than four pores, and the pore diameter is ≤15mm and the pore depth is ≤1.5mm, the second repair method can be used for repair;

[0087] Glass fiber protrusion on the pipe surface: For example, there are glass fiber protrusions on the inner and / or outer surfaces of the GRP pipe, and the height of the glass fiber protrusion is greater than 5mm;

[0088] Protrusion of resin blocks on the pipe surface: For example, there are protrusions of resin blocks on the inner and / or outer surfaces of the GRP pipe, and the protrusion height of the resin blocks is greater than 5mm;

[0089] Pipe surface wrinkles: For example, wrinkles and creases appear on the inner and / or outer surfaces of the GRP pipe;

[0090] Pipe surface scratches: For example, white scratch marks appear on the inner and / or outer surface of the GRP pipe.

[0091] The second maintenance method provided in this embodiment includes the following steps:

[0092] S2-1: Use a grinding device (such as sandpaper or a scraper) to grind the defective area of ​​the GRP pipe to be repaired to grind away the defect; the grinding area extends at least 45mm-55mm beyond the defective area, and the second patch layer is cut according to the size of the grinding area. The second patch layer includes a glass fiber surface felt, and the glass fiber surface felt can be made of alkali-free glass fiber;

[0093] S2-2: Apply resin to the polished area. The resin may be polyester resin or epoxy resin. The resin may be mixed with aluminum hydroxide reinforcing agent and accelerator to form a paste. The resin may completely soak the polished area. Place the second patch layer on the applied resin, and apply resin to the second patch layer so that the second patch layer is completely soaked with the resin.

[0094] S2-3: Cure the second patch layer at room temperature and wait for the second patch layer to be completely cured. Then use sandpaper or grinding wheel to grind and polish to make the grinding area flush with the non-grinding area around the pipe.

[0095] The GRP pipeline repair method provided in this embodiment also provides a second repair method for type B causes. Different causes are classified and processed according to their types, which can ensure that each cause receives the most suitable repair, thereby improving the repair efficiency and quality and saving the repair cost.

[0096] Example 3

[0097] Based on Example 2, the GRP pipeline maintenance method provided in this embodiment includes the following steps:

[0098] First, determine the cause type of the GRP pipe to be repaired. The cause type of the GRP pipe to be repaired may include a Class C cause. If the GRP pipe to be repaired is a Class C cause, use the third repair method.

[0099] In this embodiment, the Class C causes include: pipeline leakage, such as water droplets on the surface of the GRP pipeline.

[0100] The third maintenance method provided in this embodiment includes the following steps:

[0101] If the leakage points of the GRP pipe to be repaired are dense, consider directly cutting off the leaking section of the pipe;

[0102] If the GRP pipe to be repaired has multiple leakage points and there is no structural damage to the GRP pipe to be repaired. Figure 2The GRP pipe to be repaired has multiple leakage points 1, and the pressure of the GRP pipe to be repaired can be reduced to 2 bar. If no water droplets, moisture or other leakage occurs after the pressure of the GRP pipe to be repaired is reduced to 2 bar, the GRP pipe to be repaired will be downgraded to a pressure-free pipe used only for gravity flow, and no further repair is required; if there are still water droplets and other leakage after the pressure of the GRP pipe to be repaired is reduced to 2 bar, the GRP pipe to be repaired will be scrapped and no further repair will be performed;

[0103] If the pressure of the GRP pipe to be repaired (diameter ≤ 600mm) drops to 2bar, there is only one point of leakage in the GRP pipe to be repaired, that is, there is only a single point of leakage, and there is no structural damage to the GRP pipe to be repaired. Figure 3 The GRP pipe to be repaired shown has only one leakage point 1. Then, a grinding device (such as sandpaper or a scraper) can be used to grind the defective area of ​​the GRP pipe to be repaired. The third patch layer can be cut according to the size of the leakage point 1, and resin is coated on the grinded area. The third patch layer is placed on the coated resin so that the third patch layer is completely soaked with the resin. The first sealing layer is used to seal the defective area from the inside of the pipe. The first sealing layer includes glass fiber felt cloth and glass fiber surface felt used for lamination. The specific glass fiber felt cloth and glass fiber surface felt can be arranged alternately or not. Preferably, the first sealing layer includes two layers of glass fiber felt cloth and one layer of glass fiber surface felt. The first sealing layer extends at least 150mm beyond the defective area; the third patch layer includes 430-470g / m 2 Glass fiber felt cloth and 800~840g / m 2 Glass fiber roving cloth, preferably 450g / m 2 Glass fiber felt cloth and 820g / m 2 Glass fiber roving cloth, specifically glass fiber felt cloth and glass fiber roving cloth can be arranged alternately or not. The side length of the third patch layer is not less than 250mm, and a quarter slope can be reserved at the edge of the third patch layer to facilitate the pasting of the third patch layer;

[0104] Furthermore, the first layer and the last layer of the third patch layer are both glass fiber felt cloth. For example, if the third patch layer has three layers, the first and last layers (outermost layers) of the third patch layer are glass fiber felt cloth, and the middle layer is glass fiber roving cloth. With this arrangement, the first and last layers of the third patch layer are designed to be glass fiber felt cloth. This design enhances the overall strength and toughness of the patch layer, ensuring that the repair area can better resist external force impact and internal pressure changes. At the same time, the glass fiber felt cloth has a tight structure and evenly distributed fibers, which can effectively fill the tiny pores on the surface, improve the sealing of the repair area, and prevent further leakage. In addition, the felt cloth also has good resin adsorption and penetration properties, which helps to evenly distribute the resin in the patch layer, thereby enhancing the overall structural stability and durability of the patch layer.

[0105] Furthermore, when the pressure of the GRP pipe to be repaired is 6 Bar, the number of layers of the third patch layer is three; when the pressure of the GRP pipe to be repaired is 9-12 Bar, the number of layers of the third patch layer is five; when the pressure of the GRP pipe to be repaired is 15-16 Bar, the number of layers of the third patch layer is seven.

[0106] Specifically, for example, when the pressure of the GRP pipe to be repaired is 6 Bar, the number of layers of the third patch layer is three; when the pressure of the GRP pipe to be repaired is 9 Bar, the number of layers of the third patch layer is five; when the pressure of the GRP pipe to be repaired is 10 Bar, the number of layers of the third patch layer is five; when the pressure of the GRP pipe to be repaired is 12 Bar, the number of layers of the third patch layer is five; when the pressure of the GRP pipe to be repaired is 15 Bar, the number of layers of the third patch layer is seven; when the pressure of the GRP pipe to be repaired is 16 Bar, the number of layers of the third patch layer is seven.

[0107] If the GRP pipe to be repaired (diameter ≤ 600mm) has only a little leakage but the source of the leakage cannot be determined, and the pipe has no structural damage. Then grind the defective area of ​​the GRP pipe to be repaired along the circumference of the pipe and extend it to a circle around the pipe, apply resin to the grinded area, and use the first wrapping layer to completely wrap the defective area along the circumference of the pipe. The first wrapping layer wraps the GRP pipe to be repaired along the circumference. Coat the first wrapping layer with resin so that the first wrapping layer is completely soaked with resin; use the second sealing layer to seal the defective area from the inside of the pipe, and the second sealing layer includes glass fiber felt cloth and glass fiber surface felt used for lamination. The specific glass fiber felt cloth and glass fiber surface felt can be arranged alternately or not. It is preferred that the second sealing layer includes two layers of glass fiber felt cloth and one layer of glass fiber surface felt. The second sealing layer extends at least 150mm beyond the defective area; the first wrapping layer includes 430-470g / m 2 Glass fiber felt cloth and 800~840g / m 2Glass fiber roving cloth, preferably 450g / m 2 Glass fiber felt cloth and 820g / m 2 Fiberglass roving.

[0108] Furthermore, the first layer and the last layer of the first wrapping layer are both glass fiber felt cloth. For example, if the first wrapping layer has three layers, the first and last layers of the first wrapping layer are glass fiber felt cloth, and the middle layer is glass fiber roving cloth.

[0109] Furthermore, when the pressure of the GRP pipe to be repaired is 6 Bar, the number of layers of the first wrapping layer is three; when the pressure of the GRP pipe to be repaired is 9-12 Bar, the number of layers of the first wrapping layer is five; when the pressure of the GRP pipe to be repaired is 15-16 Bar, the number of layers of the first wrapping layer is seven.

[0110] For example, when the pressure of the GRP pipe to be repaired is 6 Bar, the number of layers of the first wrapping layer is three; when the pressure of the GRP pipe to be repaired is 9 Bar, the number of layers of the first wrapping layer is five; when the pressure of the GRP pipe to be repaired is 10 Bar, the number of layers of the first wrapping layer is five; when the pressure of the GRP pipe to be repaired is 12 Bar, the number of layers of the first wrapping layer is five; when the pressure of the GRP pipe to be repaired is 15 Bar, the number of layers of the first wrapping layer is seven; when the pressure of the GRP pipe to be repaired is 16 Bar, the number of layers of the first wrapping layer is seven.

[0111] If the GRP pipe to be repaired is leaking due to structural damage, consider directly cutting off the leaking section of the pipe.

[0112] The GRP pipeline repair method provided in this embodiment also provides a third repair method for type C causes. The third repair method subdivides the leakage problem into multi-point leakage and single-point leakage, and adopts different treatment methods according to the specific situation, which reflects a high degree of pertinence and higher construction efficiency. For pipelines with slight multi-point leakage, after meeting specific requirements, they can be downgraded to a pressure-free pipeline used only for gravity flow, avoiding unnecessary scrapping and improving resource utilization. For single-point leakage, a combined internal and external repair method (external patch + internal seal) is adopted, which greatly improves the reliability of the repair. For situations where the source of the leakage cannot be determined, a full-circle wrapping method is adopted to ensure the comprehensiveness of the repair. Glass fiber fine felt cloth and glass fiber coarse yarn cloth are alternately laminated to enhance the overall strength of the patch. The combination of the two can provide excellent mechanical properties in all directions. The side length of the third patch layer is set to be not less than 250 mm, ensuring that the patch can completely cover the damaged area and its surroundings, providing sufficient safety margin for repair, and the sealing layer extends at least 150 mm beyond the defective area to ensure complete sealing.

[0113] The external patch and internal sealing layer work together to form a powerful dual protection system, repairing the pipe from both inside and outside, greatly improving the reliability and durability of the repair. Adequate coverage and extension help maintain long-term repair effects and reduce future maintenance needs.

[0114] Example 4

[0115] Based on Example 3, the GRP pipeline maintenance method provided in this embodiment includes the following steps:

[0116] First, determine the cause type of the GRP pipe to be repaired. The cause type of the GRP pipe to be repaired may include type D causes. If the GRP pipe to be repaired has type D causes, use the fourth repair method.

[0117] In this embodiment, the type D causes include: pipeline delamination, such as separation between the layers of the GRP pipeline laminate.

[0118] The fourth maintenance method provided in this embodiment includes the following steps:

[0119] Assess the degree of pipeline delamination;

[0120] If only the outer layer of the GRP pipe to be repaired is delaminated, the delaminated area can be ground off, dust removed, and then resin coated on the ground area. The coated resin is cured at room temperature, or cured at elevated temperatures using an infrared oven, etc. Wait for the resin to fully cure, then use sandpaper or a grinding wheel to grind and polish until the ground area is flush with the non-ground area around the pipe.

[0121] If the delaminated area penetrates deep into the inner lining of the GRP pipe to be repaired, the delaminated area can be ground off, resin is coated on the ground area, and the fourth patch layer is laid on the coated resin so that the fourth patch layer is completely soaked with the resin, and the fourth patch layer is cured at room temperature, or the fourth patch layer is cured at a high temperature using an infrared oven, etc., and the fourth patch layer is completely cured. Then, sandpaper or a grinding wheel is used for grinding and polishing to make the ground area flush with the non-ground area around the pipe, and finally, dust on the surface of the pipe is removed; the fourth patch layer of this embodiment includes 430-470g / m 2 Glass fiber mat, preferably 450g / m 2 Fiberglass Felt.

[0122] The GRP pipe repair method provided in this embodiment also provides a fourth repair method for Class D causes. Different treatment methods are adopted according to the different degrees of stratification (surface stratification and deep lining stratification), so as to achieve accurate repair of Class D causes. For slight surface stratification, simple grinding and resin coating methods are adopted to avoid excessive repair and save materials and time. For stratification deep into the lining, a more comprehensive repair method is adopted to ensure the thoroughness and reliability of the repair.

[0123] Example 5

[0124] Based on Example 4, the GRP pipeline maintenance method provided in this embodiment includes the following steps:

[0125] First, determine the cause type of the GRP pipe to be repaired. The cause type of the GRP pipe to be repaired may include type E causes. If the GRP pipe to be repaired has type E causes, use the fifth repair method.

[0126] In this embodiment, the E-type causes include: damage to the outer layer of the pipeline, such as local damage to the outer layer of the GRP pipeline.

[0127] The fifth maintenance method provided in this embodiment includes the following steps:

[0128] Determine the type of GRP pipe to be repaired;

[0129] If the GRP pipe to be repaired is a pressure-free pipe used only for gravity flow: use a grinding device (such as sandpaper or a scraper) to grind the defective area of ​​the GRP pipe to be repaired, grind away the defect, apply resin to the grinded area, and use the fifth patch layer to fill the damaged area, for example, use the fifth patch layer to fill the damaged groove, and after filling the damaged area, continue to laminate the fifth patch layer to cover the entire grinded area, and the diameter of the grinded area is at least four times the thickness of the fifth patch layer filling the damaged area; apply resin to the fifth patch layer so that the fifth patch layer is completely saturated with the resin, cure the fifth patch layer at room temperature, wait for the fifth patch layer to be completely cured, and then use sandpaper or a grinding wheel to grind and polish so that the grinded area is flush with the non-grinded area around the pipe. In this embodiment, the fifth patch layer may include glass fiber fine felt cloth and glass fiber coarse yarn cloth used for alternating lamination, and the first layer and the last layer of the fifth patch layer are both glass fiber fine felt cloth;

[0130] If the GRP pipe to be repaired is a pressurized pipe: the defective area of ​​the GRP pipe to be repaired can be grinded along the circumference of the pipe and extended to a circle around the pipe, resin is coated on the grinded area, and the second wrapping layer is used to fill the damaged area along the circumference of the pipe. After the damaged area is filled, the second wrapping layer is continued to cover the entire grinded area. The extension length of the grinded area in the axial direction of the pipe is at least four times the thickness of the second wrapping layer filling the damaged area. Resin is coated on the second wrapping layer so that the second wrapping layer is completely soaked with resin. The second wrapping layer includes glass fiber felt cloth and glass fiber roving cloth used for alternating lamination, and the first layer and the last layer of the second wrapping layer are both glass fiber felt cloth.

[0131] The GRP pipeline repair method provided in this embodiment provides corresponding repair methods for different types of causes. Specifically, different repair methods are used according to whether the pipeline is a non-pressure pipeline used only for gravity flow or a pressurized pipeline, so as to achieve accurate repair of type E causes; the size of the grinding area is related to the filling thickness (for example, at least four times the filling thickness), ensuring sufficient repair area and improving the reliability of the repair. The full-circle wrapping method is used for pressurized pipelines to ensure the comprehensiveness and safety of the repair and meet the special requirements of pressurized pipelines.

[0132] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A GRP pipeline maintenance method, characterized in that: The following steps are involved: Determine the cause type of the GRP pipeline to be repaired, the cause type includes Class A causes; If the GRP pipe to be repaired has a Class A cause, use the first repair method; Category A causes include: at least one of the following: pipeline surface cracks, pipeline surface bulges, pipeline surface indentations, pipeline surface white spots, and pipeline lining or surface layer loss; The first maintenance method includes the following steps: S1-1: Grind the defective area of ​​the GRP pipe to be repaired, the grinding area extends at least 45mm-55mm beyond the defective area, cut multiple first patch layers, the first patch layer includes glass fiber fine felt cloth and glass fiber coarse yarn cloth used for lamination; S1-2: Apply resin to the polished area and place the first patch layer on the applied resin; S1-3: Rolling each first patch layer to make each first patch layer completely soaked with resin; S1-4: Curing and grinding the first patch layer to make the ground area flush with the surface of the non-ground area around the pipe.

2. A GRP pipeline repair method according to claim 1, characterized in that: The cause type also includes type B cause. If the GRP pipe to be repaired is type B cause, the second repair method is used; Category B causes include at least one of the following: pits on the pipe surface, pores on the pipe surface, protruding glass fibers on the pipe surface, protruding resin blocks on the pipe surface, wrinkles on the pipe surface, and scratches on the pipe surface; The second maintenance method includes the following steps: S2-1: Grind the defective area of ​​the GRP pipe to be repaired, the grinding area extends at least 45mm-55mm beyond the defective area, and cut the second patch layer, which includes a glass fiber surface felt; S2-2: coating resin on the polished area, placing the second patch layer on the coated resin, and coating the second patch layer with resin so that the second patch layer is completely soaked with the resin; S2-3: The second patch layer is cured and ground so that the ground area is flush with the non-ground area of ​​the surrounding surface of the pipe.

3. A GRP pipeline repair method according to claim 1, characterized in that: The cause type also includes type C cause. If the GRP pipe to be repaired is type C cause, the third repair method is used; Category C causes include: pipe leakage; The third maintenance method includes the following steps: If there are multiple leakages in the GRP pipe to be repaired, and there is no structural damage to the GRP pipe to be repaired, and the leakage disappears after the pressure of the GRP pipe to be repaired is reduced to 2 bar, the GRP pipe to be repaired will be downgraded to a non-pressure pipe used only for gravity flow, and no further repair is required; If the leakage does not disappear after the pressure of the GRP pipe to be repaired is reduced to 2 bar, the GRP pipe to be repaired shall be scrapped and no longer repaired; if the GRP pipe to be repaired has only a little leakage after the pressure of the GRP pipe to be repaired is reduced to 2 bar, and the GRP pipe to be repaired has no structural damage, the defective area of ​​the GRP pipe to be repaired shall be polished, the third patch layer shall be cut, resin shall be coated on the polished area, and the third patch layer shall be placed on the coated resin so that the third patch layer is completely soaked with the resin; the first sealing layer shall be used to seal the defective area from the inside of the pipe, the first sealing layer shall include glass fiber fine felt cloth and glass fiber surface felt used for lamination, and the first sealing layer shall extend at least 150mm outside the defective area; the third patch layer shall include 430-470g / m 2 Glass fiber felt cloth and 800~840g / m 2 Glass fiber roving cloth, the side length of the third patch layer shall not be less than 250mm; If the GRP pipe to be repaired has only a small leakage but the source of the leakage cannot be determined, and the pipe has no structural damage, grind the defective area of ​​the GRP pipe to be repaired along the circumference of the pipe and extend it to a circle around the pipe, apply resin to the grinded area, use the first wrapping layer to completely wrap the defective area along the circumference of the pipe, and apply resin to the first wrapping layer so that the first wrapping layer is completely soaked with resin; use the second sealing layer to seal the defective area from the inside of the pipe, the second sealing layer includes glass fiber fine felt cloth and glass fiber surface felt used for lamination, and the second sealing layer extends at least 150mm outside the defective area; the first wrapping layer includes 430~470g / m 2 Glass fiber felt cloth and 800~840g / m 2 Fiberglass roving.

4. A GRP pipeline repair method according to claim 1, characterized in that: The cause type also includes type D cause. If the GRP pipe to be repaired has type D cause, the fourth repair method is used; Category D causes include: pipeline delamination; The fourth maintenance method comprises the following steps: Assess the degree of pipeline delamination; If only the surface of the GRP pipe to be repaired is delaminated, grind off the delaminated area, remove the dust, apply resin to the polished area, cure it, and grind it to make the polished area flush with the non-polished area around the GRP pipe to be repaired; If the delaminated area penetrates deep into the GRP pipe lining to be repaired, grind off the delaminated area, apply resin on the polished area, lay the fourth patch layer on the coated resin so that the fourth patch layer is completely soaked with resin, and finally cure and grind to make the polished area flush with the non-polished area around the pipe; the fourth patch layer includes 430~470g / m 2 Fiberglass Felt.

5. A GRP pipeline repair method according to claim 1, characterized in that: The cause type also includes type E cause. If the GRP pipe to be repaired has type E cause, the fifth repair method is used; Category E causes include: damage to the outer layer of the pipe; The fifth maintenance method includes the following steps: Determine the type of GRP pipe to be repaired; If the GRP pipe to be repaired is a non-pressure pipe used only for gravity flow: grind the defective area of ​​the GRP pipe to be repaired, apply resin on the grinded area, use the fifth patch layer to fill the damaged area, and continue to use the fifth patch layer to cover the entire grinded area after the damaged area is filled. The diameter of the grinded area is at least four times the thickness of the fifth patch layer used to fill the damaged area. Apply resin on the fifth patch layer so that the fifth patch layer is completely soaked with resin. Curing and grinding the fifth patch layer so that the grinded area is flush with the non-grinded area around the pipe. The fifth patch layer includes glass fiber felt cloth and glass fiber roving cloth used for lamination. The first and last layers of the fifth patch layer are both glass fiber felt cloth. If the GRP pipe to be repaired is a pressurized pipe: grind the defective area of ​​the GRP pipe to be repaired along the circumference of the pipe and extend it to one circle of the pipe, apply resin on the grinded area, use the second wrapping layer to fill the damaged area, and continue to use the second wrapping layer to cover the entire grinded area after the damaged area is filled. The extending length of the grinded area in the axial direction of the pipe is at least four times the thickness of the second wrapping layer filling the damaged area. Resin is applied to the second wrapping layer so that the second wrapping layer is completely soaked with resin. The second wrapping layer includes glass fiber felt cloth and glass fiber roving cloth used for lamination, and the first layer and the last layer of the second wrapping layer are both glass fiber felt cloth.

6. A GRP pipeline repair method according to claim 3, characterized in that: The first and last layers of the third patch layer are both glass fiber felt cloth.

7. A GRP pipeline repair method according to claim 3, characterized in that: When the pressure of the GRP pipe to be repaired is 6 Bar, the number of layers of the third patch layer is three; when the pressure of the GRP pipe to be repaired is 9-12 Bar, the number of layers of the third patch layer is five; when the pressure of the GRP pipe to be repaired is 15-16 Bar, the number of layers of the third patch layer is seven.

8. A GRP pipeline repair method according to claim 3, characterized in that: The first and last layers of the first wrapping layer are both glass fiber felt cloth.

9. A GRP pipeline repair method according to claim 3, characterized in that: When the pressure of the GRP pipeline to be repaired is 6 Bar, the number of layers of the first wrapping layer is three; when the pressure of the GRP pipeline to be repaired is 9-12 Bar, the number of layers of the first wrapping layer is five; when the pressure of the GRP pipeline to be repaired is 15-16 Bar, the number of layers of the first wrapping layer is seven.

10. A GRP pipeline repair method according to any one of claims 1 to 9, characterized in that: If the repaired area of ​​the GRP pipe to be repaired exceeds 5% of the inner or outer surface area of ​​the GRP pipe to be repaired, no further repair will be carried out; the number of repairs within one meter of the axial direction of the GRP pipe to be repaired shall not exceed one time.

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