Gate plate double-valve-seat sealing structure and flat gate valve

Abstract

The invention discloses a flashboard double-valve-seat sealing structure and a flat gate valve, and the sealing structure comprises a large valve seat and a small valve seat which are distributed on the two sides of a flashboard, a small valve seat mounting groove is formed in the near-flashboard end of the large valve seat, the far-flashboard end is cooperatively inserted into the large valve seat mounting groove of the valve body, the far-flashboard end surface is sealed with the bottom surface of the large valve seat mounting groove through a sealing ring, and the excircle surface is cooperatively contacted with the side surface of the large valve seat mounting groove through a wear-resistant ring; one end of the small valve seat is inserted into the small valve seat mounting groove in a matched mode, the other end face of the small valve seat is contacted with the side face of the flashboard, the end face of the small valve seat far away from the flashboard is sealed with the bottom face of the small valve seat mounting groove through a metal sealing ring, and the outer circle face is contacted with the side face of the small valve seat mounting groove in a matched mode. The small valve seat and the large valve seat are in axial clearance fit, and an opening is formed in the metal sealing ring along the line and faces the axis. The sealing structure can prevent sealing failure caused by high temperature and high pressure, can compensate for sealing gap changes, prolongs the service life, can guarantee sealing performance under high temperature and high pressure, and is suitable for bidirectional fluid working conditions.

Description

Technical Field

[0001] The present invention belongs to the field of flat gate valves, and in particular relates to a gate plate double valve seat sealing structure and a flat gate valve. Background Art

[0002] The flat gate valve is a common shut-off valve that opens and closes by switching the position of a flat gate. The movement direction of the gate is perpendicular to the direction of the fluid. Valve seats are set between the two sides of the gate and the valve body. The two sides of the gate slide and seal with the valve seats. When the gate is in the closed position, the water flow is cut off. When the gate is in the open position, the water flow can pass through the through hole on the gate.

[0003] The gate is typically fitted with a single valve seat on either side, with a limited number of attempts at double-seat designs. Both single- and double-seat designs currently utilize a rigid sealing structure that lacks elastic compensation capabilities. This makes leakage more likely when exposed to high temperatures, high pressures, or media containing impurities. The sealing effect is particularly unstable in bidirectional flow situations. Furthermore, long-term friction between the gate and the seat can easily damage the sealing surface, resulting in a short service life and the need for frequent maintenance. Summary of the Invention

[0004] The purpose of the present invention is to provide a gate plate double valve seat sealing structure and a flat gate valve containing the above-mentioned sealing structure. The sealing structure can prevent sealing failure caused by high temperature and high pressure expansion, compensate for changes in sealing gaps, improve service life, ensure sealing under high temperature and high pressure, and is suitable for bidirectional fluid working conditions.

[0005] The technical solution adopted in the present invention is: The cam is pressed against the valve core, and the cam is pressed against the valve body to push the cam out of the valve body, so that the cam can slide in and out of the valve core, thereby preventing the cam from sliding out of the valve body.

[0006] Preferably, the axial clearance between the large valve seat and the small valve seat is 1-2 mm, and the opening size and shape of the metal sealing ring are obtained by simulation based on its own material and the working conditions of the flat gate valve, to ensure that the deformation of the metal sealing ring at the initial closure of the gate plate can provide appropriate elastic preload, and the deformation under the designed high temperature and high pressure working conditions can provide sufficient force on the large valve seat.

[0007] Preferably, the cross section of the metal sealing ring is symmetrically C-shaped, U-shaped, V-shaped or parabolic.

[0008] Preferably, the fluid passage holes on the large valve seat and the small valve seat are aligned with the fluid channel of the valve body, and when the flat gate valve is opened, the through hole of the gate plate is aligned with the fluid channel of the valve body.

[0009] Preferably, the end surface of the large valve seat far from the gate plate is sealed to the bottom surface of the large valve seat installation groove through two layers of inner and outer sealing rings.

[0010] Preferably, the sealing ring is made of a non-metallic material with an inner cavity; or, the sealing ring is made of a metal material with an opening, and the opening of the inner sealing ring faces the axis, and the opening of the outer sealing ring is away from the axis.

[0011] Preferably, the wear-resistant ring is broken somewhere. When installing, the wear-resistant ring is first expanded and put on the outer circle, and then the wear-resistant ring is clamped into the ring groove on the outer circle, and then the wear-resistant ring is reset and tightened.

[0012] Preferably, both the large valve seat and the small valve seat are made of nickel-based alloy and their surfaces are sprayed with tungsten carbide, and the gate plate surface is sprayed with tungsten carbide.

[0013] Preferably, the metal sealing ring is made of inconel 718.

[0014] Preferably, the wear-resistant ring is made of 316SS.

[0015] Preferably, the valve body is formed in one piece from cast steel.

[0016] A flat gate valve comprises the above-mentioned gate plate double valve seat sealing structure.

[0017] The beneficial effects of the present invention are: This sealing structure replaces the conventional single valve seat with a large valve seat and a small valve seat, and the axial clearance between the large valve seat and the small valve seat is matched to prevent the two from getting stuck due to expansion under high temperature and high pressure, resulting in sealing failure. In addition, the large valve seat and the small valve seat are sealed axially with metal sealing rings. The metal sealing rings have elastic openings, which can provide elastic preload when the gate is closed, compensate for changes in the sealing gap caused by temperature or wear, and improve service life. When high-temperature and high-pressure fluid passes through, the openings can expand to provide a force in the opposite direction of the fluid to the large valve seat, thereby enhancing the overall sealing of the valve seat and ensuring sealing performance under high temperature and high pressure (the sealing grade can reach API 6A Level VI). In addition, the outer cylindrical surfaces of the large valve seat and the small valve seat are matched with the side surfaces of their respective mounting grooves through wear-resistant rings. On the one hand, they can play a guiding role during assembly of the two, allowing them to be installed smoothly to avoid damage, and on the other hand, they can prevent wear after assembly. In addition, the large valve seat and the small valve seat are distributed on both sides of the gate, suitable for bidirectional fluid conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 Schematic diagram of the gate double valve seat sealing structure in an embodiment of the present invention.

[0020] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0021] Figure 3 It is an assembly diagram of the large valve seat and the small valve seat in an embodiment of the present invention.

[0022] In the figure: 1-gate; 2-small valve seat; 3-large valve seat; 4-valve body; 5-metal sealing ring; 6-sealing ring; 7-wear-resistant ring. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0026] The features and performance of the present application are further described in detail below with reference to the embodiments.

[0027] Example 1 This embodiment discloses a gate double valve seat sealing structure, such as Figures 1 to 3 As shown, it includes a large valve seat 3 and a small valve seat 2; wherein: the large valve seat 3 is distributed on both sides of the gate plate 1, and the large valve seat 3 is provided with a fluid through hole. The end of the large valve seat 3 near the gate plate 1 is provided with a small valve seat installation groove, and the end of the far gate plate 1 is inserted into the large valve seat installation groove of the valve body 4. The end surface of the far gate plate 1 is sealed with the bottom surface of the large valve seat installation groove through the sealing ring 6, and the outer cylindrical surface is in contact with the side surface of the large valve seat installation groove through the wear-resistant ring 7. Figure 1 and Figure 2 The small valve seat 2 is distributed on both sides of the gate 1. The small valve seat 2 is provided with a fluid through hole. One end of the small valve seat 2 is inserted into the small valve seat installation groove, and the other end face is in contact with the side surface of the gate 1. The end face of the small valve seat 2 far from the gate 1 is sealed with the bottom surface of the small valve seat installation groove through a metal sealing ring 5, and the outer cylindrical surface is in contact with the side surface of the small valve seat installation groove through a wear-resistant ring 7. Figure 1 and Figure 2 The small valve seat 2 and the large valve seat 3 are matched with axial clearance, such as Figure 2 and Figure 3 As shown, the metal sealing ring 5 has an opening along the line and the opening is toward the axis. The opening is elastic and can expand when subjected to high temperature and internal support force. The two sides of the opening respectively press against the bottom surface of the small valve seat mounting groove and the bottom surface of the metal sealing ring mounting groove of the small valve seat 2.

[0028] This sealing structure replaces the conventional single valve seat with a large valve seat 3 and a small valve seat 2. The large and small valve seats 3 and 2 are fitted with an axial clearance to prevent them from seizing and causing seal failure due to expansion caused by high temperature and high pressure. Furthermore, the large and small valve seats 3 and 2 are axially sealed with a metal sealing ring 5. This metal sealing ring 5 has an elastic opening that not only provides elastic preload when the gate 1 is closed, compensating for changes in the sealing gap caused by temperature or wear, thereby increasing service life, but also expands when high-temperature and high-pressure fluid passes through, exerting a force on the large valve seat 3 in the opposite direction of the fluid flow, thereby enhancing the overall sealing performance of the valve seat and ensuring sealing performance under high temperature and high pressure conditions (sealing grade can reach API 6A Class VI). Furthermore, the outer surfaces of the large and small valve seats 3 and 2 are fitted with wear-resistant rings 7 to the side surfaces of their respective mounting grooves. These wear-resistant rings 7 serve as guides during assembly, ensuring smooth installation and preventing damage, and also prevent wear after assembly. Furthermore, the large and small valve seats 3 and 2 are located on either side of the gate 1, making them suitable for bidirectional fluid flow conditions.

[0029] In this sealing structure, the axial clearance between the large valve seat 3 and the small valve seat 2 and the opening size and shape of the metal sealing ring 5 need to be precisely designed and controlled, among which: the axial clearance between the large valve seat 3 and the small valve seat 2 is obtained based on the experience and experiments of metal expansion under high temperature and high pressure, and 1-2mm is the optimal range; the opening size and shape of the metal sealing ring 5 are related to its own material and the working conditions of the flat gate valve, and are obtained through simulation based on its own material and the working conditions of the flat gate valve to ensure that the deformation of the metal sealing ring 5 at the initial closure of the gate plate 1 can provide a suitable elastic preload, and the deformation under the designed high temperature and high pressure working conditions can provide sufficient force on the large valve seat 3.

[0030] In this embodiment, the cross-section of the metal sealing ring 5 can be symmetrically C-shaped, U-shaped, V-shaped or parabolic. Different shapes can provide different deformation amounts and thus different reaction forces. The specific shape can be obtained based on simulation.

[0031] In this embodiment, the fluid passage holes on the large valve seat 3 and the small valve seat 2 are aligned with the fluid channel of the valve body 4. When the flat gate valve is opened, the through hole of the gate plate 1 is aligned with the fluid channel of the valve body 4, realizing full-bore circulation and reducing pressure loss.

[0032] In this embodiment, if Figures 1 to 3 As shown, the end face of the large valve seat 3 far from the gate plate 1 is sealed with the bottom surface of the large valve seat mounting groove by two layers of inner and outer sealing rings 6. Because the large valve seat mounting groove in the valve body 5 is difficult to process and its bottom surface accuracy is difficult to control, in order to ensure the sealing effect between the end face of the large valve seat 3 far from the gate plate 1 and the bottom surface of the large valve seat mounting groove, two layers of inner and outer sealing rings 6 are used.

[0033] In this embodiment, the sealing ring 6 can be made of a non-metallic material with an inner cavity; or Figure 2 and Figure 3 As shown, the sealing ring 6 can be made of a metal material with an opening, with the inner sealing ring 6 opening facing the axis and the outer sealing ring 6 opening away from the axis. Since the axial gap between the large valve seat 3 and the small valve seat 2 is on the side close to the gate 1, the metal sealing ring 5 can provide floating adjustment. Therefore, the sealing ring 6 on the side away from the gate 1 does not necessarily have to play a floating adjustment role, so a conventional non-metallic sealing member can be used. Of course, to improve the sealing effect, it can be made of a metal material with an opening like the metal sealing ring 5. In this way, the large valve seat 3 and the valve body 4 can also be floated and adjusted, and the sealing effect is better.

[0034] In this embodiment, the wear-resistant ring 7 is broken at a certain point. When installing, the wear-resistant ring 7 is first expanded and put on the outer circle, then the wear-resistant ring 7 is snapped into the ring groove on the outer circle, and then the wear-resistant ring 7 is reset and tightened. This installation method can ensure the integrity of the wear-resistant ring 7 and does not require it to be assembled in sections.

[0035] In this embodiment, the large valve seat 3 and the small valve seat 2 are both made of nickel-based alloy and sprayed with tungsten carbide on the surface. The gate plate 1 is also sprayed with tungsten carbide on the surface to ensure wear resistance and corrosion resistance.

[0036] In this embodiment, the metal sealing ring 5 is made of inconel 718.

[0037] In this embodiment, the wear-resistant ring 7 is made of 316SS.

[0038] In this embodiment, the valve body 4 is formed in one piece by cast steel.

[0039] Example 2 This embodiment discloses a flat gate valve, which includes the above-mentioned gate plate double valve seat sealing structure. The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

Claims

1. A gate double valve seat sealing structure, characterized by: It includes a large valve seat and a small valve seat distributed on both sides of the gate, and both the large valve seat and the small valve seat are provided with fluid through holes; the near-gate end of the large valve seat is provided with a small valve seat mounting groove, and the far-gate end is inserted into the large valve seat mounting groove of the valve body, the far-gate end face is sealed with the bottom surface of the large valve seat mounting groove through a sealing ring, and the outer cylindrical surface is in contact with the side surface of the large valve seat mounting groove through a wear-resistant ring; one end of the small valve seat is inserted into the small valve seat mounting groove, and the other end face is in contact with the side surface of the gate, the far-gate end face of the small valve seat is sealed with the bottom surface of the small valve seat mounting groove through a metal sealing ring, and the outer cylindrical surface is in contact with the side surface of the small valve seat mounting groove through a wear-resistant ring; the small valve seat and the large valve seat are matched with axial clearance, the metal sealing ring has an opening along the line and the opening faces the axis center, the opening is elastic and can expand at high temperature and under internal support force, and the two sides of the opening respectively press against the bottom surface of the small valve seat mounting groove and the bottom surface of the metal sealing ring mounting groove of the small valve seat.

2. The gate double valve seat sealing structure according to claim 1, characterized in that: The axial clearance between the large valve seat and the small valve seat is 1-2mm. The opening size and shape of the metal sealing ring are obtained through simulation based on its own material and the working conditions of the flat gate valve, ensuring that the deformation of the metal sealing ring at the initial closure of the gate can provide appropriate elastic preload, and the deformation under the designed high temperature and high pressure working conditions can provide sufficient force on the large valve seat.

3. The gate double valve seat sealing structure according to claim 1 or 2, characterized in that: The cross section of the metal sealing ring is symmetrical C-shaped, U-shaped, V-shaped or parabolic.

4. The gate double valve seat sealing structure according to claim 1, characterized in that: The fluid through holes on the large valve seat and the small valve seat are aligned with the fluid channel of the valve body. When the flat gate valve is opened, the through hole of the gate is aligned with the fluid channel of the valve body.

5. The gate double valve seat sealing structure according to claim 1, characterized in that: The end surface of the large valve seat far from the gate plate is sealed with the bottom surface of the large valve seat installation groove through two layers of inner and outer sealing rings.

6. The gate double valve seat sealing structure according to claim 5, characterized in that: The sealing ring is made of a non-metallic material with an inner cavity; or, the sealing ring is made of a metal material with an opening, and the opening of the inner sealing ring faces the axis, and the opening of the outer sealing ring is away from the axis.

7. The gate double valve seat sealing structure according to claim 1, characterized in that: If the wear-resistant ring is broken somewhere, when installing, first expand the wear-resistant ring and put it on the outer circle, then insert the wear-resistant ring into the ring groove on the outer circle, and then reset and tighten the wear-resistant ring.

8. The gate double valve seat sealing structure according to claim 1, characterized in that: The large valve seat and the small valve seat are both made of nickel-based alloy and the surface is sprayed with tungsten carbide, and the gate surface is sprayed with tungsten carbide.

9. The gate double valve seat sealing structure according to claim 1, characterized in that: The metal sealing ring is made of inconel718.

10. The gate double valve seat sealing structure according to claim 1, characterized in that: The wear ring is made of 316SS.

11. The gate double valve seat sealing structure according to claim 1, characterized in that: The valve body is made of cast steel.

12. A flat gate valve, characterized in that: It comprises the gate double valve seat sealing structure as described in any one of claims 1 to 11.

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