Improved structure of valve ball of floating ball valve with water hammer reduction function

Abstract

The utility model relates to a floating ball valve for reducing water hammer effect, which comprises a valve body, a valve seat, a valve ball and a valve rod, characterized in that a diffusion-constriction-diffusion type leakage hole is formed in the center position of the non-sealing surface of the valve ball, and the leakage hole is connected with the valve ball inner cavity and the valve body flow channel. When the fluid medium produces instantaneous impact on the valve ball during the opening or closing process of the valve, part of the fluid enters the valve ball inner cavity through the leakage hole, thereby buffering the direct force of the fluid on the valve ball, weakening the water hammer effect and prolonging the service life of the valve ball and the sealing surface. The utility model has simple structure and is convenient to manufacture, and can be widely applied to various floating ball valve products.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a floating ball valve that can reduce water hammer effect. Background Technology

[0002] Floating ball valves are widely used in pipeline systems due to their simple structure and good sealing performance. During the opening and closing of the ball valve, especially in high-pressure, high-flow-rate media environments, the fluid exerts a momentary impact on the valve ball, creating a water hammer effect. Water hammer not only causes pressure fluctuations in the pipeline system but also leads to uneven stress on the valve ball, thereby accelerating wear between the valve ball and seat, reducing sealing performance, and shortening the valve's service life.

[0003] In existing technologies, water hammer effects are usually reduced by slow-closing mechanisms, bypass pipelines, or pressure reducing devices. However, these methods are complex in structure and costly, and are not suitable for the widespread use of small or standardized floating ball valves. Utility Model Content

[0004] To overcome the above shortcomings, this utility model proposes a floating ball valve structure that reduces water hammer effect. By opening a vent hole at the center of the non-sealing surface of the valve ball, some fluid enters the valve ball chamber at the moment of opening or closing, thereby buffering the impact force of the fluid, reducing water hammer effect, and improving the service life of the valve.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A floating ball valve with a pressure-reducing and venting structure includes a valve body, a valve cover, a valve ball, a valve stem, and a valve seat. The valve ball is a floating structure and can move within the valve cavity under fluid pressure. The valve ball has a sealing surface that mates with the valve seat and a non-sealing back surface.

[0007] The core improvement of this utility model lies in: opening a diffusion-contraction-diffusion type vent hole at the center of the non-sealing surface of the valve ball.

[0008] The valve body has a fluid channel inside, and the valve ball is disposed in the fluid channel of the valve body. The valve seat is fixed on the valve body and cooperates with the valve ball to achieve a seal. One end of the valve stem is connected to the valve ball, and the other end extends out of the valve body and is connected to the drive mechanism. The drive mechanism is used to drive the valve stem to rotate the valve ball, thereby opening and closing the valve. The valve ball has a hollow structure with an internal cavity. The valve ball is characterized by having a vent hole at the center of the non-sealing surface. The vent hole includes a first diffusion section, a contraction section, and a second diffusion section along the fluid direction, forming a "diffusion-contraction-diffusion" flow channel structure that penetrates the non-sealing surface of the valve ball and communicates with the internal cavity of the valve ball, thereby venting a portion of the fluid in the fluid channel into the cavity of the valve ball.

[0009] Furthermore, the diameter of the vent hole is determined based on the nominal diameter and working pressure of the floating ball valve. The ratio of the minimum diameter D1 of the contraction section to the nominal diameter DN of the valve is 0.02 to 0.08 to ensure the matching of the venting flow rate with the valve stability. The cone angle of the diffuser section is 5° to 15° to prevent fluid separation and achieve smooth pressure recovery. When the nominal diameter of the floating ball valve is large or the working pressure is high, the diameter of the vent hole can be appropriately increased to ensure sufficient venting flow rate; when the nominal diameter is small or the working pressure is low, the diameter of the vent hole can be reduced to avoid excessive fluid leakage affecting the normal flow rate of the valve.

[0010] Furthermore, the inner wall of the vent hole is smoothed with a roughness Ra≤0.4μm to reduce the resistance of the fluid during the venting process, ensure smooth venting, and at the same time avoid the formation of eddies in the fluid due to the roughness of the inner wall, which would further aggravate pressure fluctuations.

[0011] Furthermore, the valve ball is made of stainless steel, such as 304 stainless steel or 316 stainless steel, which has good corrosion resistance and strength, can withstand fluid impact and pressure changes, and extends the service life of the valve ball.

[0012] The positive and progressive effects of this invention are as follows:

[0013] (a) Reduce the water hammer effect

[0014] By setting a vent hole in the center of the non-sealing surface of the valve ball, some fluid enters the inner cavity of the valve ball at the moment of opening and closing, thereby diverting and buffering the fluid impact, effectively reducing the water hammer effect caused by the rapid opening and closing of the valve, and improving the operational stability of the pipeline system.

[0015] (ii) Improve the service life of valve ball and valve seat

[0016] Because the vent hole balances the pressure inside and outside the valve ball, it prevents excessive force on one side of the valve ball, reduces the long-term impact and wear on the valve seat sealing surface, and thus extends the service life of the valve seat and valve ball.

[0017] (III) Simple structure and easy to manufacture

[0018] This invention only requires machining a vent hole on the non-sealing surface of the valve ball to achieve its function, without the need for additional auxiliary parts. This avoids the use of complex slow-closing mechanisms or bypass devices, reduces manufacturing difficulty and production costs, and is suitable for large-scale promotion and application.

[0019] (iv) Does not affect normal sealing performance

[0020] The vent hole is located on the non-sealing surface of the valve ball, avoiding the sealing contact area with the valve seat. This ensures the sealing reliability of the valve in the opening and closing state and prevents leakage problems.

[0021] (v) Wide range of applications

[0022] This technical solution allows for flexible adjustment of the size and shape of the vent hole according to different nominal diameters, pressure ratings, and media conditions, exhibiting good versatility and applicability to various specifications of floating ball valves. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a floating ball valve that can reduce water hammer effect, which is a preferred embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the internal structure of the valve ball of this utility model.

[0025] Figure 3 This is a schematic cross-sectional view of the valve ball of this utility model.

[0026] In the diagram: 1. Connecting sleeve; 2. Valve stem; 3. Valve body; 4. Valve cover; 5. Valve ball; 6. Valve seat; 7. Flow passage; 8. Chamber; 9. Drain hole; 10. Non-sealing surface. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] like Figure 1 As shown, a floating ball valve for reducing water hammer effect includes a connecting sleeve 1, a valve stem 2, a valve body 3, a valve cover 4, a valve ball 5, a valve seat 6, and a flow passage 7.

[0029] Valve stem 2: The upper end of the valve stem is connected to the actuator through a connecting sleeve, and the lower end is fixed to the valve ball 5, which is used to drive the valve ball to rotate.

[0030] Valve body 3: The valve body has a flow channel for the flow of fluid medium, and valve seats 6 are installed at both ends of the valve body.

[0031] Valve ball 5: The valve ball is rotated by the valve stem 2, switching between the open and closed positions. The valve ball has a hollow structure, forming an inner cavity inside.

[0032] Valve seat 6: The valve seat is used to seal with the outer surface of the valve ball 5 to realize the opening and closing function of the valve.

[0033] The key technical feature of this utility model is that a vent hole 9 is machined at the center of the non-sealing surface of the valve ball 5.

[0034] like Figure 2As shown, the structure of the vent hole 9 in the valve ball 5 is as follows: the vent hole 9 is a through-hole in a diffusion-contraction-diffusion pattern, with one end connected to the flow channel of the valve body and the other end connected to the inner cavity of the valve ball. The vent hole is positioned in the area where the valve ball 5 does not contact the valve seat 6, avoiding the sealing pair to ensure that the sealing performance is not affected.

[0035] The function of the drain hole is as follows: when the valve is opened and closed quickly, some fluid enters the inner cavity of the valve ball through the drain hole 9, so that the fluid impact force is diverted and buffered, thereby reducing the instantaneous impact on the valve ball and reducing the water hammer effect.

[0036] The central axis of the vent hole 9 coincides with the geometric center line of the valve ball 5, ensuring uniform fluid distribution when it enters the valve ball's inner cavity and preventing eccentric force on the valve ball. The cross-sectional shape of the vent hole 9 is circular, and its diameter is designed according to the valve's nominal diameter, medium pressure, and flow velocity conditions to ensure a balance between mitigating water hammer and maintaining the strength of the valve ball.

[0037] The inner cavity of the valve ball 5 serves as a buffer chamber, temporarily accommodating some fluid during valve opening and closing. After the operation stabilizes, the fluid is gradually released back into the flow channel, effectively maintaining the pressure balance inside and outside the valve ball, further reducing wear between the valve seat and the valve ball, and improving the service life of the valve.

[0038] Furthermore, the number of vent holes 9 described in this invention can be designed as one or more as needed. When multiple vent holes are provided, they can be symmetrically distributed on the non-sealing surface of the valve ball 5 to further enhance the buffering effect.

[0039] In summary, this invention effectively mitigates the water hammer effect by providing a vent hole on the non-sealing surface of the floating ball valve, ensuring the valve's sealing performance and improving the service life of the ball and seat.

Claims

1. A floating ball valve for reducing water hammer, comprising a connecting sleeve (1), a valve stem (2), a valve body (3), a valve cover (4), a valve ball (5), and a valve seat (6); the valve body (3) has a fluid channel (7) inside, the valve ball (5) is disposed in the fluid channel (7) of the valve body (3), and the valve seat (6) is fixed on the valve body (3) and cooperates with the valve ball (5); one end of the valve stem (2) is connected to the valve ball (5), and the other end extends out of the valve body (3) and is connected to a drive mechanism; the valve ball (5) has a hollow structure and forms a cavity (8) inside; characterized in that: A vent hole (9) with diffusion-contraction-diffusion is provided at the center of the non-sealing surface (10) of the valve ball (5). The vent hole (9) penetrates the non-sealing surface (10) of the valve ball (5) and is connected to the cavity (8) inside the valve ball (5).

2. A floating ball valve for reducing water hammer according to claim 1, characterized in that: The drain hole (9) is characterized by a diffusion-contraction-diffusion pattern.

3. A floating ball valve for reducing water hammer according to claim 1, characterized in that: The inner wall roughness Ra of the drain hole (9) is ≤0.4μm.

4. A floating ball valve for reducing water hammer according to claim 1, characterized in that: The valve ball (5) is made of stainless steel.

5. A floating ball valve for reducing water hammer according to claim 4, characterized in that: The stainless steel is 304 stainless steel or 316 stainless steel.

6. A floating ball valve for reducing water hammer according to claim 1, characterized in that: The valve seat (6) is made of any one of the following materials: hard alloy.

7. A floating ball valve for reducing water hammer according to claim 1, characterized in that: The connecting sleeve (1) is used to connect a manual drive mechanism or an electric or pneumatic drive mechanism to drive the valve.

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