A reinforced structure and manufacturing process of a D-shaped sealing ring for a seawater butterfly valve

Abstract

The application belongs to the technical field of sealing and particularly relates to a D-shaped sealing ring reinforcing structure for a seawater butterfly valve and a manufacturing process. The sealing ring reinforcing structure comprises a sealing ring body, and a through hole is formed in the sealing ring body. The sealing ring body is annular. Uniformly distributed through holes are formed in the sealing ring body. The sealing ring body comprises a framework fabric and rubber, and the framework fabric has two layers and is nested in the rubber. The application has the beneficial effects that the application has a simple structure, is simple to process and manufacture, has good adhesion between the framework fabric and the rubber, and has no large tearing and damage after installation and use, and the product quality is obviously better than that of the original sealing ring. The application can meet the high reliability use requirements of nuclear power plants and has a positive effect on improving nuclear safety.

Description

Technical Field

[0001] This invention belongs to the field of sealing technology, specifically relating to a reinforced structure and manufacturing process of a D-type sealing ring for seawater butterfly valves. Background Technology

[0002] Currently, most D-type sealed seawater butterfly valves are imported products, and the valve seal mainly relies on the performance of the D-type rubber sealing ring. D-type seals have advantages such as simple structure, convenient maintenance, and reliable performance. However, due to long-term corrosion and erosion from seawater, as well as damage from marine organisms, the sealing ring is prone to breakage and tearing, severely affecting the valve's sealing performance. For nuclear power plants, seawater is the final source of heat, and equipment reliability directly impacts nuclear safety. Summary of the Invention

[0003] The purpose of this invention is to provide a reinforced structure and manufacturing process for a D-type sealing ring for seawater butterfly valves. This invention improves the performance of the sealing ring through structural design and manufacturing process, enhances its resistance to tearing and breakage, and improves the sealing reliability of seawater butterfly valves, thereby meeting the requirements of nuclear power plants.

[0004] The technical solution of the present invention is as follows: A D-type sealing ring reinforcement structure for seawater butterfly valve, comprising a sealing ring body, wherein a through hole is opened on the sealing ring body.

[0005] The sealing ring body has a ring-shaped structure.

[0006] The sealing ring body has evenly distributed through holes.

[0007] The sealing ring body comprises a skeleton fabric and rubber, with the skeleton fabric consisting of two layers nested within the rubber.

[0008] The skeleton fabric is a layered material, with the fabric in the middle and adhesive materials bonded to both sides of the fabric by adhesive liquid.

[0009] The skeleton fabric is made of nylon.

[0010] A manufacturing process for a D-type sealing ring reinforced structure for a seawater butterfly valve includes the following steps:

[0011] Step 1: Design and manufacture the mold according to the dimensions of the D-type sealing ring;

[0012] Step 2: Select nylon fiber fabric as the reinforcing skeleton material.

[0013] Step 3: Treat the surface of the nylon fiber fabric with an activator to remove oil and moisture;

[0014] Step 4: The main body rubber compound is hydrogenated nitrile rubber. After the rubber compound is mixed and its performance is tested and meets the standards, it will proceed to the next process.

[0015] Step 5: After the rubber compound is mixed evenly, it is passed through a thin tube 5 to 7 times, then rolled into sheets and placed in a dryer for later use;

[0016] Step 6: After thorough re-kneading, the compounded rubber is sheeted into 1.5-2mm thin sheets, then cut into 100×100mm pieces. These pieces are then soaked in toluene and ethyl acetate for 24 hours, and finally poured into a mixer and stirred for at least 8 hours to prepare a 1:3 rubber solution. The prepared rubber solution should be stored below 40℃.

[0017] Step 7: Add the adhesive to the bulk adhesive solution and stir well. Then, apply the adhesive solution evenly to the nylon fiber fabric and dry the treated nylon fiber fabric at room temperature.

[0018] Step 8: Lay the sheet-like compound and nylon fiber fabric in the hot mold in the order of compound-fabric-compound-fabric-compound, and then vulcanize using a flat vulcanizing machine;

[0019] Step 9: Test the warp and weft tensile strength and elongation at break of the composite specimens, and select the composite specimens with high bonding strength for use;

[0020] Step 10: Place the composite test piece into the mold and perform compression molding and vulcanization;

[0021] Step 11: After shaping, demold to obtain the reinforced sealing ring.

[0022] In step 2, the nylon fiber fabric is designated as Nylon Silk 543.

[0023] The basic formulation of hydrogenated nitrile rubber in step 4 is as follows: 100g hydrogenated nitrile rubber; 15g carbon black; 10g silica; 4g vulcanizing agent DCP; and 25g other components.

[0024] The vulcanization conditions in step 8 are (165±5)℃ / 15MPa×40min.

[0025] The beneficial effects of this invention are as follows: The structure is simple, processing and manufacturing are easy, the bonding effect between the reinforcing fabric and rubber is good, and no large-scale tearing or damage occurs after installation and use. The product quality is significantly better than that of the original sealing ring. Applying the product of this invention can meet the high reliability requirements of nuclear power plants and has a positive effect on improving nuclear safety. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a reinforced D-type sealing ring structure for a seawater butterfly valve provided by the present invention;

[0027] Figure 2 for Figure 1 Sectional view of part A in the diagram;

[0028] Figure 3 This is a schematic diagram of the skeleton fabric structure;

[0029] Figure 4 The manufacturing process flow diagram of a D-type sealing ring reinforcement structure for a seawater butterfly valve provided by the present invention.

[0030] In the diagram: 1. Sealing ring body, 2. Through hole, 3. Reinforcing fabric, 4. Rubber, 5. Fabric, 6. Adhesive liquid, 7. Adhesive material. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] The D-type sealing ring reinforcement structure for seawater butterfly valves provided by this invention effectively improves its tear resistance. Structurally, it employs a built-in double-layer flat-laid high-strength reinforcing fabric, which not only significantly enhances the sealing ring's tear resistance but also strengthens its flexural properties and fatigue resistance during opening and closing. Actual measured performance is superior to common wrap-around structures. The disadvantage of wrap-around structures is that when the sealing ring is compressed, the reinforcing fabric layer is close to the outer layer of the sealing ring, resulting in poor contact surface elasticity and the formation of micro-gaps, leading to poor sealing performance. Furthermore, its flexural properties and fatigue resistance are not as good as those of the built-in double-layer structure.

[0033] From a manufacturing process perspective, the built-in flat-lay structure simplifies product processing and manufacturing. Moreover, the flat-lay method allows for better adhesion between the fabric and rubber, making it less prone to delamination and resulting in higher bonding strength.

[0034] This patented invention enhances the tear resistance of the D-type sealing ring by improving its structure and manufacturing process, thereby improving the sealing performance of the seawater butterfly valve, meeting the usage requirements of the culvert isolation valve, and reducing the number of culvert operations.

[0035] like Figure 1 As shown, a D-type sealing ring reinforcement structure for a seawater butterfly valve includes a sealing ring body 1, which is an annular structure with uniformly distributed through holes 2. Figure 2 As shown, the sealing ring body 1 includes a skeleton fabric 3 and a rubber 4. The skeleton fabric 3 has two layers and is nested inside the rubber 4.

[0036] like Figure 3 As shown, the skeleton fabric 3 is a layered structure, including a five-layer structure, with fabric 5 in the middle, and the fabric 5 is bonded to adhesive 7 by adhesive 6.

[0037] The skeleton fabric 5 is made of nylon, which has the characteristics of high strength, good fatigue resistance, and good impact resistance. At the same time, nylon fibers have strong adhesion to rubber. After multiple coats of the main adhesive on both sides, they are pressed together with the rubber material to form a rubber-fabric composite structure with high tear strength and good adhesion.

[0038] This invention adds a double layer of high-strength fabric inside the D-type sealing ring as a keel to enhance tear resistance and prevent large-scale tearing of the sealing ring during use.

[0039] The specific manufacturing process is as follows:

[0040] 1) Design and manufacture molds according to the dimensions of the D-type sealing ring;

[0041] 2) Nylon fiber fabric is selected as the reinforcing skeleton material, with Nylon Silk 543 being the preferred grade;

[0042] 3) Treat the surface of the nylon fiber fabric with an activator to remove oil and moisture;

[0043] 4) The preferred main body rubber compound is hydrogenated nitrile rubber. The basic formula is: 100 parts hydrogenated nitrile rubber; 15 parts carbon black; 10 parts silica; 4 parts vulcanizing agent DCP; and 25 parts other components. After the rubber compound has been mixed and its performance tested to meet the standards, it will proceed to the next stage of the process.

[0044] 5) After the rubber compound is mixed evenly, it is passed through a thin tube 5 to 7 times, then rolled into sheets and placed in a dryer for later use;

[0045] 6) After thorough re-kneading, the compounded rubber is sheeted into 1.5–2 mm thin sheets, then cut into 100×100 mm pieces. These pieces are then soaked in toluene and ethyl acetate for 24 hours, and then poured into a mixer for stirring for at least 8 hours to prepare a 1:3 solution. The prepared solution should be stored below 40°C.

[0046] 7) The preferred adhesive is Chemlock 205. Add it to the bulk adhesive solution and stir until homogeneous. Then, evenly apply the adhesive solution (6) onto the nylon fiber fabric (5). Dry the treated nylon fiber fabric at room temperature for 30 hours.

[0047] 8) The sheet-like compound and nylon fiber fabric are laid in the hot mold in the order of compound (7)-fabric (5)-compound (7)-fabric (5)-compound (7) and then vulcanized using a flat vulcanizing machine. The vulcanization conditions are (165±5)℃ / 15MPa×40min.

[0048] 9) Test the warp and weft tensile strength and elongation at break of the composite specimens, and select the composite specimens with high bonding strength for use;

[0049] 10) Place the composite test piece into the mold and perform compression molding and vulcanization;

[0050] 11) After shaping, the reinforced sealing ring is obtained by demolding.

Claims

1. A D-type sealing ring reinforced structure for a seawater butterfly valve, characterized in that: It includes a sealing ring body with a through hole; the sealing ring body includes a skeleton fabric and rubber, the skeleton fabric has two layers, which are laid flat and nested inside the rubber; the skeleton fabric is a layered material, with the fabric in the middle and the rubber material bonded to both sides of the fabric by adhesive.

2. The D-type sealing ring reinforcement structure for a seawater butterfly valve as described in claim 1, characterized in that: The sealing ring body has a ring-shaped structure.

3. The D-type sealing ring reinforcement structure for a seawater butterfly valve as described in claim 1, characterized in that: The sealing ring body has evenly distributed through holes.

4. The D-type sealing ring reinforcement structure for a seawater butterfly valve as described in claim 1, characterized in that: The skeleton fabric is made of nylon.

5. A manufacturing process for a D-type sealing ring reinforcement structure for a seawater butterfly valve, characterized in that, Based on the D-type sealing ring reinforcement structure for a seawater butterfly valve as described in claim 1, the process includes the following steps: Step 1: Design and manufacture the mold according to the dimensions of the D-type sealing ring; Step 2: Select nylon fiber fabric as the reinforcing skeleton material. Step 3: Treat the surface of the nylon fiber fabric with an activator to remove oil and moisture; Step 4: The main body rubber compound is hydrogenated nitrile rubber. After the rubber compound is mixed and its performance is tested and meets the standards, it will proceed to the next process. Step 5: After the rubber compound is mixed evenly, it is passed through a thin tube 5-7 times, then rolled into sheets and placed in a dryer for later use; Step 6: After the compounded rubber is fully re-kneaded, it is cut into 1.5-2mm thin sheets, then cut into 100×100mm small pieces, soaked in toluene and ethyl acetate for 24 hours, then poured into a mixer and stirred for no less than 8 hours to make a rubber solution. The rubber solution should be stored in an environment below 40℃ after it is made. Step 7: Add the adhesive to the bulk adhesive solution and stir well. Then, apply the adhesive solution evenly to the nylon fiber fabric and dry the treated nylon fiber fabric at room temperature. Step 8: Lay the sheet-like compound and nylon fiber fabric in the hot mold in the order of compound-fabric-compound-fabric-compound, and then vulcanize using a flat vulcanizing machine; Step 9: Test the warp and weft tensile strength and elongation at break of the composite specimens, and select the composite specimens with high bonding strength for use; Step 10: Place the composite test piece into the mold and perform compression molding and vulcanization; Step 11: After shaping, demold to obtain the reinforced sealing ring.

6. The manufacturing process of the D-type sealing ring reinforcement structure for a seawater butterfly valve as described in claim 5, characterized in that: In step 2, the nylon fiber fabric is designated as Nylon Silk 543.

7. The manufacturing process of the D-type sealing ring reinforcement structure for a seawater butterfly valve as described in claim 5, characterized in that: The basic formulation of hydrogenated nitrile rubber in step 4 is as follows: 100g hydrogenated nitrile rubber; 15g carbon black; 10g silica; 4g vulcanizing agent DCP; and 25g other components.

8. The manufacturing process of the D-type sealing ring reinforcement structure for a seawater butterfly valve as described in claim 5, characterized in that: The vulcanization conditions in step 8 are (165±5)℃ / 15 MPa×40min.

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