Knife gate valve with stable flashboard structure
By setting a top guide block, a middle guide block, and a bottom guide block in the valve body, the problem of unstable gate structure in knife gate valves under bidirectional medium flow is solved, thereby improving the stability and sealing performance of the gate, expanding the scope of application, and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG NANHUI VALVE CO LTD
- Filing Date
- 2025-06-26
- Publication Date
- 2026-05-08
AI Technical Summary
Existing knife gate valves have unstable gate structure when the medium flows in both directions, resulting in poor sealing performance and limited application range.
A top guide block, a middle guide block, and a bottom guide block are installed inside the valve body. Through the cooperation of these guide blocks with the gate, the gate is kept vertical, which enhances the gate's bending resistance and sealing performance.
It achieves stability and sealing performance of the gate under bidirectional flow conditions, expands the scope of application, reduces the impact of medium flow rate, and lowers processing costs.
Smart Images
Figure CN224214736U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of knife gate valve technology, and more specifically to a knife gate valve with a stable gate structure. Background Technology
[0002] Knife gate valves belong to the shut-off valve category and are characterized by their compact size, low flow resistance, and ease of assembly and disassembly. They are currently widely used in industrial and urban pipelines. When a knife gate valve needs to be opened or closed, the valve stem is moved by rotating the handwheel to drive the nut, which in turn moves the gate up and down. Most existing knife gate valves are unidirectional valves, meaning the medium flows from the large-diameter channel of the valve body to the small-diameter channel. Sealing is achieved by the medium pressure pressing the gate against the sealing surface of the valve seat. However, in certain operating environments, the medium flows bidirectionally, or the knife gate valve needs to be installed in reverse. In this case, the medium flows from the small-diameter channel to the large-diameter channel of the valve body. The gate, pushed by the medium, bends and deforms, partially separating from the sealing surface of the valve seat, resulting in medium leakage. Therefore, existing knife gate valves suffer from limited applicability and poor gate structure stability. Utility Model Content
[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a knife gate valve that can realize bidirectional flow, has a stable gate structure, and has good sealing performance.
[0004] To achieve the above objectives, this utility model provides the following technical solution: a knife gate valve with a stable gate structure, comprising a valve body, a gate inserted into the valve body, and a valve seat capable of forming a hard seal with the gate. The valve body is provided with a small flow channel and a large flow channel located on both sides of the gate. The inner wall of the large flow channel is provided with a top guide block located at the highest point of the inner wall of the large flow channel, two middle guide blocks located on both sides of the vertical plane containing the diameter of the large flow channel and at a height lower than the height of the top guide block, and two bottom guide blocks located on both sides of the vertical plane containing the diameter of the large flow channel and at a height lower than the height of the middle guide blocks on the same side. The gate is kept vertical by the top guide block, middle guide block and bottom guide block contacting the gate in sequence.
[0005] As a further improvement of this utility model, the lengths of the bottom guide block and the top guide block in the circumferential direction of the inner wall of the large flow channel are both smaller than the length of the middle guide block in the circumferential direction of the inner wall of the large flow channel.
[0006] As a further improvement of this utility model, the widths of the bottom guide block and the top guide block in the direction of the inner diameter of the large flow channel are both smaller than the width of the middle guide block in the direction of the inner diameter of the large flow channel.
[0007] As a further improvement of this utility model, the middle guide block is provided with a through hole for the flow of medium.
[0008] As a further improvement of this utility model, the surface of the guide block facing the gate is arc-shaped and convex towards the gate.
[0009] As a further improvement of this utility model, both of the aforementioned guide blocks are symmetrically arranged relative to the vertical plane where the diameter of the large flow channel is located.
[0010] As a further improvement of this utility model, both bottom guide blocks are symmetrically arranged relative to the vertical plane where the diameter of the large flow channel is located.
[0011] The beneficial effects of this utility model are as follows: By having the top guide block, middle guide block, and bottom guide block contact the top of the gate in sequence, the gate remains vertical. Compared with existing technologies, this design can meet the requirements of bidirectional flow of the medium and has a wider range of applications. The design of the top and middle guide blocks can provide different degrees of support when the medium flow decreases and a large thrust is generated locally on the gate, indirectly improving the bending resistance of the gate and ensuring that the gate always remains vertical, which is conducive to the formation of an effective hard seal between the gate and the valve seat. The design of the bottom guide block can provide support for the bottom edge of the gate and effectively compensate for the... The thin bottom thickness of the gate, which makes it prone to deformation, indirectly improves the sealing stability between the gate and the valve seat. The design of independent top guide blocks, middle guide blocks, and bottom guide blocks reduces the impact on medium flow and lowers processing costs compared to the design of setting U-shaped or O-shaped guides on the inner wall of the valve body. The design of setting two bottom guide blocks symmetrically on the vertical plane of the large flow channel diameter, compared to the design of setting one bottom guide block and positioning it at the lowest point of the inner wall of the large flow channel, avoids the accumulation of medium at the bottom of the large flow channel, facilitates the flow of medium, and indirectly improves the smoothness of the gate moving downward into place. Attached Figure Description
[0012] Figure 1 This is the front view of the present invention;
[0013] Figure 2 for Figure 1 A schematic diagram at point AA;
[0014] Figure 3 This is the left view of the present invention;
[0015] Figure 4 This is a perspective view of the guide block of this utility model.
[0016] Reference numerals in the attached diagram: 1. Valve body; 2. Gate; 3. Valve seat; 4. Small flow channel; 5. Large flow channel; 6. Top guide block; 7. Middle guide block; 8. Bottom guide block; 9. Through hole. Detailed Implementation
[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Identical components are indicated by the same reference numerals.
[0018] Reference Figures 1 to 4 As shown, a knife gate valve with a stable gate structure in this embodiment includes a valve body 1, a gate 2 inserted into the valve body 1, and a valve seat 3 that can form a hard seal with the gate 2. The valve body 1 is provided with a small flow channel 4 and a large flow channel 5 located on both sides of the gate 2, respectively. The valve seat 3 is located in the small flow channel 4 and is coaxially arranged with the small flow channel 4. The gate 2 is a knife gate and the bottom edge is an inclined surface.
[0019] Based on the aforementioned existing technology, during the processing and assembly process, the gate 2 is moved downwards to the closed position, with one side of the gate 2 contacting the sealing surface of the valve seat 3. Then, a top guide block 6 is moved into the large flow channel 5 and brought into contact with the gate 2. The top guide block 6 is welded to the highest point of the inner wall of the large flow channel 5 using welding technology. Next, one of the middle guide blocks 7 is moved into the large flow channel 5 and brought into contact with the gate 2. The height of the middle guide block 7 is lower than that of the top guide block 6. The middle guide block 7 is welded to the inner wall of the large flow channel 5 using welding technology, and the middle guide block 7 is located on one side of the vertical plane containing the diameter of the large flow channel 5. The aforementioned process of installing the middle guide block 7 is repeated. Another middle guide block 7 is welded to the other side of the vertical plane where the diameter of the large flow channel 5 is located. Both middle guide blocks 7 are located at the horizontal plane where the diameter of the large flow channel 5 is located. Then, one of the bottom guide blocks 8 is moved into the large flow channel 5 and the bottom guide block 7 touches the inclined surface of the lower edge of the gate plate 2. The height of the bottom guide block 8 is lower than that of the middle guide block 7. The bottom guide block 8 is welded to the inner wall of the large flow channel 5 by welding technology, and the bottom guide block 8 is located on one side of the vertical plane where the diameter of the large flow channel 5 is located. The above-mentioned installation process of the bottom guide block 8 is repeated to weld the other bottom guide block 8 to the other side of the vertical plane where the diameter of the large flow channel 5 is located. Finally, the gate plate 2 is moved upward to the open state for installation and use.
[0020] The small flow channel 4 and the large flow channel 5 are respectively connected to the pipes for the medium to enter and the pipes for the medium to flow out. The medium flows from the small flow channel 4 to the large flow channel 5. During the downward movement of the gate 2, the surface of the gate 2 facing the large flow channel 5 contacts the top guide block 6 and the two middle guide blocks 7 in succession and slides relative to each other until the gate 2 moves downward into place. The inclined surface at the bottom of the gate 2 touches the bottom guide block 8. The gate 2 and the valve seat 3 form an effective hard seal, allowing the medium to accumulate in the small flow channel 4.
[0021] Compared to existing technologies, this design can meet the requirements of bidirectional media flow and has a wider range of applications. The design of the top guide block 6 and the middle guide block 7 can provide different degrees of support when the media flow decreases and a large thrust is generated locally on the gate 2, indirectly improving the bending resistance of the gate 2 and ensuring that the gate 2 always remains vertical, which is conducive to the formation of an effective hard seal between the gate 2 and the valve seat 3. The design of the bottom guide block 8 can provide support for the bottom edge of the gate 2, effectively compensating for the defect that the bottom thickness of the gate 2 is relatively thin and easily deformed, indirectly improving the bending resistance of the gate 2. Compared with the design of independent top guide block 6, middle guide block 7 and bottom guide block 8, the design of setting U-shaped or O-shaped guide parts on the inner wall of valve body 1 can reduce the impact on medium flow and reduce processing costs; the design of setting the number of bottom guide blocks 8 to two and being symmetrical about the vertical plane where the diameter of the large flow channel 5 is located can avoid the accumulation of medium at the bottom of the large flow channel 5, making it easier for the medium to flow away and indirectly improving the smoothness of the gate 2 moving downward into place.
[0022] As an improved specific implementation, when the gate 2 moves to the vicinity of the horizontal plane where the diameter of the large flow channel 5 is located, the gate 2 has a large contact area with the medium and is subjected to a large force, making the gate 2 prone to deformation. To solve the aforementioned problem, refer to... Figure 1 As shown, the lengths of the bottom guide block 8 and the top guide block 6 in the circumferential direction of the inner wall of the large flow channel 5 are both less than the length of the middle guide block 7 in the circumferential direction of the inner wall of the large flow channel 5. This design can increase the contact area between the middle guide block 7 and the gate plate 2 in the vertical direction, and at the same time shorten the stroke of the gate plate 2 from the top guide block 6 to the middle guide block 7 and then contact the middle guide block 7. The middle guide block 7 can contact the gate plate 2 in a timely and effective manner, thereby improving the bending resistance of the gate plate 2 and ensuring the stability of the gate plate 2 structure.
[0023] As one specific implementation method of the improvement, refer to Figure 1 As shown, the widths of the bottom guide block 8 and the top guide block 6 in the inner diameter direction of the large flow channel 5 are both smaller than the width of the middle guide block 7 in the inner diameter direction of the large flow channel 5. This design further increases the contact area between the middle guide block 7 and the gate plate 2 in the diameter direction of the large flow channel 5, effectively improving the supporting effect of the middle guide block 7 on the gate plate 2.
[0024] As one specific implementation of the improvement, increasing the arc length and width of the central guide block 7 will result in a larger outline size of the central guide block 7. This will cause the medium to be obstructed by the central guide block 7, thereby reducing the flow rate of the medium per unit time. To solve the aforementioned problem, refer to... Figure 1 and Figure 4As shown, while ensuring the structural strength of the two intermediate guide blocks 7, through holes 9 are opened on both intermediate guide blocks 7 to allow the medium to flow. When the medium impacts the intermediate guide blocks 7, some of the medium flows through the through holes 9. This design can minimize the impact on the medium flow rate and also reduce the impact force of the medium on the intermediate guide blocks 7, indirectly improving the connection stability between the intermediate guide blocks 7 and the inner wall of the large flow channel 5, as well as the structural stability of the intermediate guide blocks 7.
[0025] As one specific implementation of the improvement, increasing the arc length and width of the middle guide block 7 will increase the contact area between the middle guide block 7 and the gate plate 2, resulting in greater friction when the middle guide block 7 and the gate plate 2 slide relative to each other, thus affecting the opening and closing efficiency of the gate plate 2. To solve the aforementioned problem, refer to Figure 3 and Figure 4 As shown, the surface of the middle guide block 7 facing the gate 2 is arc-shaped and convex towards the gate 2. Compared with the design where the surface of the middle guide block 7 facing the gate 2 is flat, this design can reduce the contact area between the gate 2 and the middle guide block 7, which is conducive to the smooth sliding of the gate 2 relative to the middle guide block 7 and improves the opening and closing efficiency of the gate 2. At the same time, when the medium impacts the middle guide block 7, it can be diverted along the arc surface, effectively reducing the impact force of the medium on the middle guide block 7 and improving the stability of the middle guide block 7 structure.
[0026] As one specific implementation method of the improvement, refer to Figure 1 As shown, both middle guide blocks 7 are symmetrically arranged on the vertical plane relative to the diameter of the large flow channel 5. This design, compared to the design where the two middle guide blocks 7 have a height difference in the vertical direction, can ensure that the gate plate 2 is subjected to uniform force and improve the structural stability of the gate plate 2.
[0027] As one specific implementation method of the improvement, refer to Figure 1 As shown, both bottom guide blocks 8 are symmetrically arranged on the vertical plane relative to the diameter of the large flow channel 5. Compared with the design where the two bottom guide blocks 8 have a height difference in the vertical direction, this design can ensure that the bottom edge of the gate plate 2 is subjected to uniform force and improve the structural stability of the bottom edge of the gate plate 2.
[0028] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.
Claims
1. A gate valve with a stable gate structure, comprising a valve body (1), a gate (2) inserted into the valve body (1), and a valve seat (3) capable of forming a hard seal with the gate (2), wherein the valve body (1) is provided with a small flow channel (4) and a large flow channel (5) respectively located on both sides of the gate (2), characterized in that: The inner wall of the large flow channel (5) is provided with a top guide block (6) located at the highest point of the inner wall of the large flow channel (5), two middle guide blocks (7) located on both sides of the vertical plane where the diameter of the large flow channel (5) is located and their height is lower than that of the top guide block (6), and two bottom guide blocks (8) located on both sides of the vertical plane where the diameter of the large flow channel (5) is located and their height is lower than that of the middle guide block (7) on the same side. The gate (2) is kept vertical by the top guide block (6), middle guide block (7) and bottom guide block (8) touching the gate (2) one after another.
2. The gate valve with a stable gate structure according to claim 1, characterized in that: The lengths of the bottom guide block (8) and the top guide block (6) in the circumferential direction of the inner wall of the large flow channel (5) are both less than the length of the middle guide block (7) in the circumferential direction of the inner wall of the large flow channel (5).
3. A gate valve with a stable gate structure according to claim 2, characterized in that: The widths of the bottom guide block (8) and the top guide block (6) in the inner diameter direction of the large flow channel (5) are both smaller than the width of the middle guide block (7) in the inner diameter direction of the large flow channel (5).
4. A gate valve with a stable gate structure according to claim 2 or 3, characterized in that: The guide block (7) is provided with a through hole (9) for the medium to flow through.
5. A gate valve with a stable gate structure according to claim 1, 2, or 3, characterized in that: The surface of the guide block (7) facing the gate (2) is arc-shaped and convex towards the gate (2).
6. A gate valve with a stable gate structure according to claim 1, 2, or 3, characterized in that: Both of the guide blocks (7) are symmetrically arranged on the vertical plane relative to the diameter of the large flow channel (5).
7. A gate valve with a stable gate structure according to claim 1, 2, or 3, characterized in that: Both bottom guide blocks (8) are symmetrically arranged relative to the vertical plane of the diameter of the large flow channel (5).