Ball valve with scraper seat

Abstract

The utility model discloses a ball valve with scraper valve seat, solves the problem of insufficient elastic compensation capacity and poor sealing performance for scraper valve seat. The valve seat assembly includes the valve seat body, and the front side of valve seat body has the first scraper and the second scraper, the ring groove and the pocket groove are set up in the valve seat body, the soft sealing ring is filled and assembled in the ring groove, and the sealing position of soft sealing ring is between the first scraper and the second scraper, the pocket groove is set up from the inner circumferential wall of valve seat body and extends to the rear position of the first scraper and the second scraper. The sealing position of soft sealing ring is between the two scrapers, and the impurities after scraping are blocked outside the sealing surface, which reduces the wear and damage of soft sealing surface by impurities from the source, and the soft sealing ring can directly contact with the clean spherical surface, improving the sealing reliability in the medium containing impurities, and the pocket groove makes it have the elastic compensation capacity, keeps the continuous adhesion of scraper and ball, thereby maintaining the long-term effective scraping effect.

Description

Technical Field

[0001] This utility model relates to the technical field of ball valves, and in particular to a ball valve with a scraper seat. Background Technology

[0002] Ball valves, as a commonly used fluid control device, are widely used in industries such as petroleum, chemical, metallurgy, and power. They achieve the opening, closing, and regulation of flow paths through the rotation of the ball. In operating conditions containing particles, fibers, or easily fouling media, impurities can easily accumulate between the ball and the valve seat, leading to wear of the sealing surface, seal failure, or valve jamming, seriously affecting the service life and sealing reliability of the ball valve.

[0003] To address the aforementioned issues, existing technologies typically incorporate a scraper structure on the valve seat to remove deposits from the ball's surface during opening and closing. However, traditional scraper-type valve seats often suffer from the following shortcomings: Firstly, the scraper structure lacks sufficient elastic compensation. Existing valve seat scrapers are often rigidly connected to the seat body, making them prone to wear during long-term friction with the ball. This significantly reduces the fit between the scraper and the ball, weakening the impurity removal effect and exacerbating wear on subsequent sealing surfaces. Secondly, the scraper-type valve seat sealing structure is poorly designed, resulting in poor sealing reliability. Existing ball valves with scraper seats rely solely on metal hard seals or direct sealing by the valve seat body. These sealing structures lack sufficient flexible elastic deformation capacity, failing to effectively fill the minute gaps between the ball and the valve seat. This leads to insufficient sealing reliability in media containing impurities, making leakage highly likely. Utility Model Content

[0004] The purpose of this utility model is to overcome the defects of the prior art and provide a ball valve with a scraper valve seat, which solves the problems of insufficient elastic compensation and poor sealing performance of the scraper valve seat without reducing the scraping performance of the scraper.

[0005] The technical solution of this utility model includes a valve body, a ball, and a valve seat assembly. The valve seat assembly includes a valve seat body, and the front side of the valve seat body has a first scraper and a second scraper. An annular groove and a pocket groove are formed inside the valve seat body. A soft sealing ring is filled and assembled in the annular groove, and the sealing position of the soft sealing ring is located between the first scraper and the second scraper. The pocket groove is formed from the inner peripheral wall of the valve seat body and extends to the rear of the first scraper and the second scraper.

[0006] Using the above technical solution, the first and second scrapers form a dual scraping structure, which can efficiently scrape off impurities such as particles, fibers, and scale adhering to the surface of the ball during the opening and closing of the ball valve, preventing impurities from entering the sealing area. At the same time, the sealing position of the soft sealing ring is located between the two scrapers, and the scraped impurities are blocked on the outside of the sealing surface, reducing the wear and damage of impurities to the soft sealing surface from the source. The soft sealing ring can directly contact the clean ball surface, improving the sealing reliability in media containing impurities. The pocket groove extends to the rear of the scraper, and the area where the scraper is located forms a cantilever structure with a certain degree of elasticity, providing elastic deformation space for the root of the scraper, giving it elastic compensation capability, automatically compensating for the gap between the scraper and the ball, and adapting to the slight displacement between the ball and the valve seat and the wear of the scraper itself, maintaining the continuous contact between the scraper and the ball, thereby maintaining a long-term effective scraping effect.

[0007] In one possible design, several circumferentially arranged guide holes are provided between the annular groove and the pocket groove, and the guide holes connect the bottom of the pocket groove and the annular groove.

[0008] With the above design, the medium pressure can be directly introduced through the guide hole and applied to the back of the soft sealing ring to form a pressure self-tightening seal. The higher the medium pressure, the greater the sealing specific pressure, which further enhances the sealing effect, and can effectively prevent leakage, especially under low pressure or pressure fluctuation conditions.

[0009] In one possible design, the cross-section of the annular groove is trapezoidal, with the upper base of the trapezoid serving as the groove opening. This groove opening is located between the first scraper and the second scraper, separating the first scraper and the second scraper. The cross-section of the soft sealing ring is triangular, with one vertex of the soft sealing ring exposed near the groove opening between the first scraper and the second scraper, and this exposed portion contacts the sphere to form a sealing fit.

[0010] With the above design, the trapezoidal annular groove provides a stable installation support and limit for the triangular soft sealing ring, preventing it from being squeezed out or circumferentially moving under pressure. The triangular soft sealing ring and the trapezoidal annular groove form a complementary geometric structure. When the soft sealing ring is squeezed by the medium pressure, its side can fit tightly against the inner wall of the trapezoidal annular groove, which not only ensures that the preferential deformation direction protrudes towards the sphere, but also avoids failure of the sealing ring due to excessive deformation, thereby improving the anti-interference ability of the sealing structure.

[0011] In one possible design, the soft sealing ring has an annular groove on the side near the guide hole, with the annular groove facing the opening of the guide hole.

[0012] With the above design, the annular groove is directly opposite the guide hole opening, which is equivalent to forming a pressure receiving cavity. This can more efficiently convert the medium pressure into radial extrusion thrust on the soft sealing ring, increasing the contact area between the medium pressure and the soft sealing ring. After the medium enters the annular groove through the guide hole, it can act on the soft sealing ring quickly and evenly, avoiding local wear of the sealing ring caused by pressure concentration. At the same time, it makes the sealing ring more evenly stressed and more stable in deformation.

[0013] In one possible design, the soft sealing ring is made of one of the following: polytetrafluoroethylene or its filler-modified material, fluororubber, nitrile rubber, EPDM rubber, and ultra-high molecular weight polyethylene.

[0014] By adopting the above design and clearly defining the material range of the soft sealing ring, the ball valve can be flexibly selected according to different application scenarios. The selected materials all have good elasticity, wear resistance and chemical stability, and can work well with the scraper structure and pressure guiding structure. While achieving effective scraping, it ensures the long-term sealing life and reliability of the soft sealing ring, thus broadening the scope of application of this utility model. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a specific embodiment of the present utility model; Figure 2 This utility model Figure 1 A magnified view of a section at point A in the middle; Figure 3 This is a schematic diagram showing the state of the medium after it enters the pocket groove. Figure 4 This utility model Figure 3 A magnified view of a section at point B in the middle; Among them, 1. Valve body; 2. Ball; 3. Valve seat assembly; 31. Valve seat body; 311. First scraper; 312. Second scraper; 32. Annular groove; 33. Soft sealing ring; 34. Pocket groove; 35. Guide hole; 331. Annular groove. Detailed Implementation

[0016] like Figures 1 to 4 The ball valve shown includes a scraper seat, a valve body 1, a ball 2 disposed in the chamber of the valve body 1, and a seat assembly 3 disposed between the valve body 1 and the ball 2. The seat assemblies 3 are usually disposed in pairs on the upstream and downstream sides of the ball 2.

[0017] The valve seat assembly 3 includes a valve seat body 31. The valve seat body 31 is generally an annular structure, and its front side (i.e. the side near the ball 2) is integrally formed or machined with a first scraper 311 and a second scraper 312 extending in the circumferential direction, with the first scraper 311 and the second scraper 312 arranged at intervals.

[0018] Inside the valve seat body 31, an annular groove 32 is formed, extending circumferentially along the valve seat body 31. A soft sealing ring 33 is fitted within the annular groove 32. The cross-section of the annular groove 32 is trapezoidal. The upper base (i.e., the shorter side) of this trapezoid faces the ball 2 and forms a notch. This notch is located precisely between the first scraper 311 and the second scraper 312, thus clearly separating the two scrapers axially. The cross-section of the soft sealing ring 33 is configured as a triangle that matches the annular groove 32. The soft sealing ring 33 is installed in the annular groove 32 by an interference fit, with a region near one vertex of the ball 2 slightly protruding from the trapezoidal notch and exposed between the first scraper 311 and the second scraper 312. When the ball valve is closed, this exposed portion comes into close contact with the surface of the ball 2, forming a soft sealing pair.

[0019] A pocket groove 34 is also provided inside the valve seat body 31. The pocket groove 34 is opened radially and obliquely inward from the inner peripheral wall of the valve seat body 31 (i.e., the side near the valve body flow channel), and the depth direction of the pocket groove 34 (i.e., the inward extending direction) extends all the way to the rear of the first scraper 311 and the second scraper 312 (i.e., the side away from the ball 2). The first scraper 311 and the second scraper 312 form an elastic structure similar to a "cantilever beam". This structural design creates a relatively weak elastic area between the root of the first scraper 311 and the second scraper 312 and the main body of the valve seat body 31, so that the scraper has a certain elastic deformation capability, which can compensate for its own wear and the slight displacement of the ball 2, and ensure that the scraper effectively adheres to the spherical surface for a long time.

[0020] In order to convert the medium pressure into a power to enhance the seal, a number of guide holes 35 are evenly provided along the circumference of the valve seat body 31 between the annular groove 32 and the pocket groove 34. One end of these guide holes 35 is connected to the pocket groove 34, and the other end is connected to the bottom of the annular groove 32 (i.e., the bottom area of ​​the trapezoidal annular groove 32 away from the ball 2).

[0021] On the side of the soft sealing ring 33 near the guide hole 35, an annular groove 331 can be machined. This annular groove 331 is continuous in the circumferential direction and faces the openings of all the guide holes 35, forming a concentrated pressure receiving cavity.

[0022] Regarding materials, the soft sealing ring 33 can be selected according to the application conditions of the ball valve. For example, for general corrosive media, polytetrafluoroethylene (PTFE) or its filled modified materials (such as glass fiber, carbon fiber, etc., to improve wear resistance) can be selected; for high-temperature oil media, fluororubber (FKM) can be selected; for conventional oil and water media, nitrile rubber (NBR) or ethylene propylene diene monomer (EPDM) rubber can be selected; for highly abrasive slurry media, ultra-high molecular weight polyethylene (UHMW-PE) can be selected. The valve seat body 31 is usually made of metal materials, such as stainless steel or alloy steel, to ensure structural strength.

[0023] Working principle: When the ball valve is closed, the exposed apex of the soft sealing ring 33 contacts the ball 2, forming an initial seal. When there is medium pressure in the pipeline, the medium pressure enters the pocket groove 34 through the inner peripheral wall of the valve seat body 31. Subsequently, this pressure is guided to the bottom of the annular groove 32 through multiple guide holes 35 and acts directly on the back side of the soft sealing ring 33, especially in the annular groove 331 area. The medium pressure pushes the soft sealing ring 33 evenly from the back side, causing it to undergo elastic deformation and press more tightly against the surface of the ball 2, thereby achieving a self-tightening effect where the higher the pressure, the tighter the seal.

[0024] Simultaneously, the medium pressure acting on the pocket groove 34 causes a slight deformation of the elastic region at the root of the scrapers 311 and 312 towards the ball 2, providing continuous elastic compensation force for the scrapers and maintaining the fit between their scraping edges and the ball. When the ball 2 rotates, the first scraper 311 and the second scraper 312 can effectively scrape away any impurities that may be attached to their surfaces, providing a relatively clean contact surface for the soft sealing area between the two scrapers, thereby greatly improving the sealing reliability and service life of the valve under harsh operating conditions.

Claims

1. A ball valve with a scraper seat, comprising a valve body (1), a ball (2), and a seat assembly (3), characterized in that: The valve seat assembly (3) includes a valve seat body (31), the front side of which has a first scraper (311) and a second scraper (312); the valve seat body (31) has an annular groove (32) and a pocket groove (34); the annular groove (32) is filled with a soft sealing ring (33), the sealing position of which is located between the first scraper (311) and the second scraper (312); the pocket groove (34) is opened inward from the inner peripheral wall of the valve seat body (31) and extends to the rear of the first scraper (311) and the second scraper (312).

2. The ball valve with scraper seat according to claim 1, characterized in that: A plurality of circumferentially arranged guide holes (35) are provided between the annular groove (32) and the pocket groove (34), and the guide holes (35) connect the bottom of the pocket groove (34) and the annular groove (32).

3. The ball valve with scraper seat according to claim 2, characterized in that: The cross-section of the annular groove (32) is trapezoidal, and the upper base of the annular groove (32) is used as the groove opening. The groove opening is located between the first scraper (311) and the second scraper (312) and separates the first scraper (311) and the second scraper (312). The cross-section of the soft sealing ring (33) is triangular. Near one of the vertices of the soft sealing ring (33) is exposed at the groove opening between the first scraper (311) and the second scraper (312), and the exposed part contacts the sphere (2) to form a sealing fit.

4. The ball valve with scraper seat according to claim 2, characterized in that: The soft sealing ring (33) has an annular groove (331) on the side near the guide hole (35), and the annular groove (331) is directly opposite the opening of the guide hole (35).

5. The ball valve with scraper seat according to claim 1 or 2, characterized in that: The soft sealing ring (33) is made of one of the following: polytetrafluoroethylene or its filler modified material, fluororubber, nitrile rubber, EPDM rubber, and ultra-high molecular weight polyethylene.

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