Anti-corrosion sealing diaphragm for diaphragm valve

Abstract

The utility model discloses a kind of anticorrosive sealing diaphragm piece for diaphragm valve, it is related to diaphragm valve technical field, including valve stem connecting part, the valve stem connecting part lower end is provided with deformation sealing part, the deformation sealing part lower end is provided with valve body fixed part;The metal insert is provided in the valve stem connecting part inside, the upper surface of valve stem connecting part is provided with a plurality of connection screw holes, the lower surface of valve body fixed part is provided with sealing curved surface, sealing convex ring is fixedly connected in the middle of sealing curved surface, the valve body fixed part is formed by anticorrosive sealing layer, elastic transition layer and rigid support layer from outside to inside in turn laminated and vulcanization composite, the outer side of valve body fixed part is provided with sealing side ring, the utility model is through composite material and innovative mechanical structure design, effectively solve the problem that traditional diaphragm piece corrosion resistance and elasticity are incompatible, easily fatigued damage.

Description

Technical Field

[0001] This utility model relates to the field of diaphragm valve technology, specifically a corrosion-resistant sealing diaphragm sheet for diaphragm valves. Background Technology

[0002] The structure of a diaphragm valve is quite different from that of a general valve. It is a new type of valve and a special type of shut-off valve. Its opening and closing element is a diaphragm made of soft material, which separates the valve body cavity from the valve cover cavity and the drive components. It is now widely used in various fields.

[0003] Diaphragm valves are critical equipment in chemical, pharmaceutical, and food industries for handling corrosive, high-purity, or particulate fluids. The performance of their core component, the diaphragm, directly determines the valve's sealing performance, lifespan, and safety. Existing diaphragm technologies suffer from the following shortcomings: Limited material: Traditional diaphragms are mostly made of single materials such as rubber or plastic. Rubber has limited corrosion resistance and is easily swelled and corroded by strong chemical media. While pure PTFE has excellent chemical inertness, its poor cold flow properties and weak elastic recovery make it prone to permanent deformation after repeated compression, leading to poor sealing and leakage. Simple structure: Most are uniformly thick circular discs. This structure, when subjected to repeated compression from the valve stem, results in uneven stress distribution, especially in the sealing area in contact with the valve seat, where stress is most concentrated, making it most susceptible to fatigue cracking and wear, thus shortening its lifespan.

[0004] Based on this, a corrosion-resistant sealing diaphragm sheet for diaphragm valves is now provided, which can eliminate the drawbacks of existing devices. Utility Model Content

[0005] The purpose of this invention is to provide a corrosion-resistant sealing diaphragm for diaphragm valves to solve the problems in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A corrosion-resistant sealing diaphragm for a diaphragm valve includes a valve stem connection portion, a deformation sealing portion at the lower end of the valve stem connection portion, and a valve body fixing portion at the lower end of the deformation sealing portion. A metal insert is provided on the inner side of the valve stem connection part. Several threaded holes are opened through the upper surface of the valve stem connection part. A sealing curved surface is provided on the lower surface of the valve body fixing part. A sealing convex ring is fixedly connected in the middle of the sealing curved surface. The valve body fixing part is composed of an anti-corrosion sealing layer, an elastic transition layer and a rigid support layer stacked and vulcanized from the outside to the inside. A sealing side ring is provided on the outer side of the valve body fixing part.

[0007] Based on the above technical solutions, this utility model also provides the following optional technical solutions: In one alternative: the valve stem connection is reliably connected to the lower end of the valve stem via a threaded connection hole and a bolt thread connection.

[0008] In one alternative: the valve stem connection in the middle is the thickest, the valve body fixing part on the outside is the next thickest, and the deformation sealing part in between is the thinnest.

[0009] In one alternative embodiment, the sealing convex ring is composed of several concentric circular rings.

[0010] In one alternative: the metal insert is disposed inside the valve stem connection portion, and the valve stem connection portion is integrally formed by encapsulation injection molding.

[0011] In one alternative: the valve stem connection is made of perfluoroether rubber, and the deformation sealing part is made of fluororubber.

[0012] In one alternative: the anti-corrosion sealing layer is made of pure polytetrafluoroethylene, and the elastic transition layer is made of fluororubber.

[0013] In one alternative: the rigid support layer is a thermoplastic polyester.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention effectively solves the problem of traditional diaphragms being unable to simultaneously achieve corrosion resistance and elasticity, and being prone to fatigue damage, through composite materials and innovative mechanical structure design. The valve body fixing part, composed of a corrosion-resistant sealing layer made of pure polytetrafluoroethylene, an elastic transition layer made of fluororubber, and a rigid support layer made of thermoplastic polyester, achieves functional complementarity among the material layers. By designing the valve stem connection in the middle to be the thickest, followed by the valve body fixing part on the outer side, and the deformation sealing part in between to be the thinnest variable-thickness structure, it perfectly matches the stress characteristics of each area. The thinned deformation sealing part significantly reduces the stiffness of this critical bending area, making it easier to undergo flexible deformation under the action of the valve stem, effectively optimizing stress distribution, reducing fatigue stress concentration, and thus extending the service life of the diaphragm. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] Figure 2 This is a side view of the overall structure of this utility model.

[0017] Figure 3 This is a schematic diagram of the internal structure of the valve body fixing part of this utility model.

[0018] Figure 4 This is an exploded view of the overall structure of this utility model.

[0019] Figure reference numerals: 1. Valve stem connection; 2. Deformation sealing part; 3. Valve body fixing part; 301. Anti-corrosion sealing layer; 302. Elastic transition layer; 303. Rigid support layer; 4. Sealing surface; 5. Sealing convex ring; 6. Sealing side ring; 7. Connecting threaded hole; 8. Metal insert. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0021] In one embodiment, such as Figures 1-4 As shown, a corrosion-resistant sealing diaphragm for a diaphragm valve includes a valve stem connection part 1, a deformation sealing part 2 is provided at the lower end of the valve stem connection part 1, and a valve body fixing part 3 is provided at the lower end of the deformation sealing part 2. A metal insert 8 is provided on the inner side of the valve stem connecting part 1. Several connecting threaded holes 7 are opened through the upper surface of the valve stem connecting part 1. A sealing curved surface 4 is provided on the lower surface of the valve body fixing part 3. A sealing convex ring 5 is fixedly connected in the middle of the sealing curved surface 4. The valve body fixing part 3 is composed of an anti-corrosion sealing layer 301, an elastic transition layer 302 and a rigid support layer 303, which are stacked and vulcanized from the outside to the inside. A sealing side ring 6 is provided on the outer side of the valve body fixing part 3. In this embodiment, the valve stem connecting part 1 is fastened to the lower end of the valve stem by bolts passing through the connecting threaded hole 7. The internal metal insert 8 bears the main tensile stress to prevent tearing. When the valve stem is pressed down, the force is transmitted through the valve stem connecting part 1 to the deformation sealing part 2, causing it to undergo precise bending deformation, which in turn pushes the valve body fixing part 3 and its sealing curved surface 4 and sealing convex ring 5 against the valve seat to achieve sealing. In the three-layer composite structure of the valve body fixing part 3, the outer anti-corrosion sealing layer 301 resists media corrosion, the middle elastic transition layer 302 provides elastic recovery, the inner rigid support layer 303 maintains the overall shape and resists pressure, and the sealing side ring 6 fits against the valve body groove wall to form an auxiliary seal.

[0022] In one embodiment, such as Figure 4 As shown, the valve stem connecting part 1 is reliably connected to the lower end of the valve stem through the connecting threaded hole 7 and the bolt threaded connection. The bolt is screwed into the threaded hole at the lower end of the valve stem and passes through the diaphragm connecting threaded hole 7, tightly clamping the valve stem connecting part 1 between the valve stem end face and the bolt head.

[0023] In one embodiment, such as Figure 2As shown, the valve stem connection part 1, located in the middle, is the thickest, followed by the valve body fixing part 3 on the outside, while the deformation sealing part 2, located between the two, is the thinnest. The thickest valve stem connection part 1 ensures the strength and rigidity of the connection with the valve stem; the thinnest deformation sealing part 2 significantly reduces the bending stiffness, allowing this area to undergo greater and more compliant bending deformation with less force under the action of the valve stem, thereby greatly improving stress distribution and reducing fatigue damage; the second thickest valve body fixing part 3 ensures that it has sufficient support when compressed and subjected to medium pressure.

[0024] In one embodiment, such as Figure 1 As shown, the sealing ring 5 is composed of several concentric circular rings. When the sealing surface 4 presses against the valve seat, the multiple concentric circular sealing rings 5 ​​will undergo elastic deformation. Each ring forms an independent line contact sealing band, thus forming a multi-level sealing barrier. This design greatly improves the sealing reliability. If the first sealing ring fails due to wear or impurities, the subsequent sealing rings can still continue to play a role, effectively preventing media leakage.

[0025] In one embodiment, such as Figure 4 As shown, the metal insert 8 is disposed inside the valve stem connection part 1, and the valve stem connection part 1 is integrally formed by injection molding. During the injection molding process, the metal insert 8 is pre-placed into the mold cavity. Molten rubber material is injected under high pressure and wraps around the metal insert 8. After cooling, the two are firmly bonded into a whole through mechanical interlocking and chemical bonding. This process ensures that there is no relative displacement between the metal and the rubber. The metal part provides strength and connection function, while the outer rubber ensures sealing and insulation with the valve stem end face.

[0026] In one embodiment, such as Figure 1 As shown, the valve stem connection 1 is made of perfluoroether rubber, and the deformation sealing part 2 is made of fluororubber. The valve stem connection 1 uses perfluoroether rubber FFKM with top chemical resistance because it is directly exposed to the valve cover chamber and may come into contact with trace amounts of media seeping from the valve stem seal, so it needs to be extremely corrosion resistant. The main function of the deformation sealing part 2 is flexible deformation. It uses fluororubber FKM with better elasticity and lower cost. While providing good elastic recovery, it also has sufficient chemical resistance, achieving a balance between function and cost.

[0027] In one embodiment, such as Figure 3 As shown, the anti-corrosion sealing layer 301 is made of pure polytetrafluoroethylene (PTFE), and the elastic transition layer 302 is made of fluororubber. As the outermost layer that is in direct contact with the fluid medium, the anti-corrosion sealing layer 301 is made of pure polytetrafluoroethylene (PTFE) material with excellent chemical inertness. It can resist the corrosion of almost all strong acids, strong alkalis and organic solvents, fundamentally ensuring the long-term durability of the diaphragm in harsh chemical environments. It is the primary guarantee for the anti-corrosion performance of the diaphragm.

[0028] In one embodiment, such as Figure 3 As shown, the rigid support layer 303 is a thermoplastic polyester. As the inner skeleton of the composite structure, the rigid support layer 303 is made of thermoplastic polyester such as PEEK or reinforced nylon. Its main function is to provide extremely high mechanical strength and dimensional stability, resist the valve stem pressure and medium static pressure, prevent the overall diaphragm from excessive stretching or cold flow deformation, and provide solid back support for the core sealing function.

[0029] The above embodiment discloses a corrosion-resistant sealing diaphragm for a diaphragm valve. The valve stem connection 1 is fastened to the lower end of the valve stem by bolts passing through the connecting threaded hole 7. The internal metal insert 8 bears the main tensile stress to prevent tearing. When the valve stem is pressed down, the force is transmitted through the valve stem connection 1 to the deformation sealing part 2, causing it to undergo precise bending deformation. This, in turn, pushes the valve body fixing part 3 and its sealing curved surface 4 and sealing convex ring 5 against the valve seat to achieve sealing. In the three-layer composite structure of the valve body fixing part 3, the outer corrosion-resistant sealing layer 301 resists media corrosion, the middle elastic transition layer 302 provides elastic recovery, and the inner rigid support layer 303 maintains the overall shape and resists pressure. The sealing side ring 6 fits against the valve body groove wall to form an auxiliary seal.

[0030] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A corrosion-resistant sealing diaphragm for a diaphragm valve, comprising a valve stem connection part (1), wherein a deformation sealing part (2) is provided at the lower end of the valve stem connection part (1), and a valve body fixing part (3) is provided at the lower end of the deformation sealing part (2). Its features are, The valve stem connection part (1) is provided with a metal insert (8) on the inner side. The upper surface of the valve stem connection part (1) is provided with a number of threaded holes (7). The lower surface of the valve body fixing part (3) is provided with a sealing curved surface (4). A sealing convex ring (5) is fixedly connected in the middle of the sealing curved surface (4). The valve body fixing part (3) is composed of an anti-corrosion sealing layer (301), an elastic transition layer (302) and a rigid support layer (303) stacked and vulcanized from the outside to the inside. A sealing side ring (6) is provided on the outer side of the valve body fixing part (3).

2. The corrosion-resistant sealing diaphragm for a diaphragm valve according to claim 1, characterized in that, The valve stem connection part (1) is reliably connected to the lower end of the valve stem by a bolt threaded connection through a connecting threaded hole (7).

3. The corrosion-resistant sealing diaphragm for a diaphragm valve according to claim 1, characterized in that, The valve stem connection part (1) located in the middle is the thickest, followed by the valve body fixing part (3) located on the outside, while the deformation sealing part (2) located between the two is the thinnest.

4. The corrosion-resistant sealing diaphragm for a diaphragm valve according to claim 1, characterized in that, The sealing convex ring (5) is composed of several concentric circular rings.

5. The corrosion-resistant sealing diaphragm for a diaphragm valve according to claim 1, characterized in that, The metal insert (8) is disposed inside the valve stem connection (1), and the valve stem connection (1) is integrally formed by encapsulation injection molding.

6. The corrosion-resistant sealing diaphragm for a diaphragm valve according to claim 1, characterized in that, The valve stem connection part (1) is made of perfluoroether rubber, and the deformation sealing part (2) is made of fluororubber.

7. The corrosion-resistant sealing diaphragm for a diaphragm valve according to claim 1, characterized in that, The anti-corrosion sealing layer (301) is made of pure polytetrafluoroethylene, and the elastic transition layer (302) is made of fluororubber.

8. The corrosion-resistant sealing diaphragm for a diaphragm valve according to claim 1, characterized in that, The rigid support layer (303) is thermoplastic polyester.

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