A long-life shear gate valve

Abstract

This utility model belongs to the field of valve technology, and particularly relates to a long-life shear gate valve, comprising: a valve body, in which a flow channel is provided and a gate for opening and closing the flow channel is provided; a valve seat, which is disposed in the flow channel of the valve body for sealing cooperation with the gate to close the flow channel; further comprising: an elastic sealing unit, which is disposed on the valve seat and includes a supporting sealing seat that seals with the gate; and a beveled portion, which is disposed on the surface of the gate; wherein, the beveled portion can reduce the contact area between the bottom end of the gate and the bottom of the valve seat and make the gate fit the valve seat more tightly under back pressure. Compared with the prior art, this utility model improves the stability of the gate valve during operation.

Description

Technical Field

[0001] This utility model belongs to the field of valve technology, and in particular relates to a long-life shear gate valve. Background Technology

[0002] A gate valve is an opening and closing element consisting of a gate. The direction of movement of the gate is perpendicular to the direction of fluid flow. The gate valve seals by contact between the valve seat and the gate. For example, a high-temperature wear-resistant flat shear gate valve disclosed in patent application number CN202321224897.7 includes a valve body with a double gate inside. A gate frame is provided in the middle of the double gate. The double gates are connected and fixed by a spring. The top of the valve body is connected to a top cover. The top of the top cover has a flange structure. The top of the top cover is fastened to the bracket by a second nut and a second double-ended bolt. A packing pressure plate is provided on the inner side of the top of the top cover. A positioning pin structure with a round hole is provided on the outer side of the top of the top cover. One side of the packing pressure plate is fastened to the positioning pin by a hinge bolt and a fourth nut. During use, the existing shear gate valve is prone to back pressure (reverse pressure) when the gate is closed, causing the gate to shake or shift, which reduces the stability of the gate valve. In addition, the gate valve has poor sealing and corrosion resistance, which reduces the service life of the gate valve. Therefore, it is necessary to make improvements. Utility Model Content

[0003] The purpose of this invention is to address the aforementioned technical problems by providing a long-life shear gate valve, thereby effectively improving the stability and service life of the shear gate valve.

[0004] In view of this, the present invention provides a long-life shear gate valve, comprising: The valve body is provided with a flow channel and a gate for opening and closing the flow channel. A valve seat, which is disposed in the flow channel of the valve body for sealing cooperation with the gate to close the flow channel; Also includes: An elastic sealing unit is disposed on a valve seat, and the elastic sealing unit includes a supporting sealing seat that seals with the gate. A beveled portion, wherein the beveled portion is disposed on the surface of the gate plate; The inclined surface can reduce the contact area between the bottom of the gate and the bottom of the valve seat and make the gate fit the valve seat more tightly under back pressure.

[0005] In this technical solution, by setting a beveled part on the surface of the gate, when encountering back pressure, the force generated by the back pressure can be used to make the gate fit more tightly with the valve seat, effectively preventing the gate from shaking or shifting, greatly improving the stability of the gate valve during operation, and reducing safety hazards such as fluid leakage caused by gate shaking or shifting. At the same time, the elastic sealing unit can effectively improve the sealing performance of the gate valve.

[0006] In the above technical solution, the inclined surface further includes an initial inclined line on the upper part of the gate plate and an inclined surface extending from the initial inclined line to the bottom end of the gate plate, and the inclination angle of the inclined surface is 10~15°.

[0007] In the above technical solution, the elastic sealing unit further includes: The mounting bushing is mounted on the valve seat and is made of high-chromium steel. A seat groove and a sealing groove are formed between the mounting bushing and the valve seat. A first sealing strip is disposed in a sealing groove; The supporting sealing seat is radially movable in the seat groove, and the supporting sealing seat is pressed against the gate plate by a pre-tightening spring.

[0008] In the above technical solution, a snap-fit ​​protrusion is further provided on the side wall of the sealing groove, and an embedding groove is provided on the surface of the snap-fit ​​protrusion. The first sealing strip is installed in the sealing groove by cooperating with the snap-fit ​​protrusion and the embedding groove.

[0009] Furthermore, the above technical solution also includes: The second sealing strip is disposed on the outer peripheral surface of the support sealing seat, and the surface of the second sealing strip is covered with a coating.

[0010] In the above technical solution, the coating film is further composed of an aqueous polyurethane resin substrate and silicone particle filler.

[0011] The beneficial effects of this utility model are: 1. By setting a beveled section on the gate surface, when encountering back pressure, the force generated by the back pressure can be used to make the gate fit more tightly with the valve seat, effectively preventing the gate from shaking or shifting, greatly improving the stability of the gate valve during operation, and reducing safety hazards such as fluid leakage caused by gate shaking or shifting.

[0012] 2. The support sealing seat in the elastic sealing unit is always pressed tightly against the gate plate under the action of the pre-tightening spring, ensuring close contact between the support sealing seat and the gate plate; the setting of the first sealing strip and the second sealing strip further enhances the sealing performance between the mating surfaces; the coating on the surface of the second sealing strip not only improves corrosion resistance, but its uneven surface structure also enhances the sealing effect. The synergistic effect of multiple sealing measures gives the gate valve of the present invention excellent sealing performance and effectively reduces fluid leakage.

[0013] 3. The mounting bushing is made of corrosion-resistant material, which improves the corrosion resistance of the gate valve and enables it to adapt to the conveying environment of various corrosive fluids.

[0014] 4. The beveled section reduces the contact area between the bottom of the gate and the bottom of the valve seat. During the opening and closing of the gate, the friction between the gate and the valve seat is reduced, the wear of the components is reduced, and the performance of the gate valve is maintained and its service life is extended. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a specific embodiment of the present utility model.

[0017] Figure 2 This is a schematic diagram of the valve seat structure of this utility model.

[0018] Figure 3 This is a schematic diagram of the inclined surface structure of this utility model.

[0019] Figure 4 This is a schematic diagram of the elastic sealing unit structure of this utility model.

[0020] Figure 5 This is a schematic diagram of the structure of the second sealing strip of this utility model.

[0021] The markings in the diagram are as follows: 1. Valve body; 100. Flow channel; 2. Gate; 3. Valve seat; 4. Elastic sealing unit; 40. Support sealing seat; 41. Mounting bushing; 42. Seat groove; 43. Sealing groove; 44. First sealing strip; 45. Preload spring; 46. Snap-fit ​​protrusion; 47. Embedded groove; 5. Beveled part; 50. Initial tilt line; 6. Second sealing strip; 7. Coating; 70. Waterborne polyurethane resin substrate; 71. Silicone particle filler. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] In the description of this application, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0024] Valve body structure In this embodiment, the valve body 1 is made of ductile iron, which has high strength, toughness, and wear resistance, meeting the requirements of gate valves under various operating conditions. The internal flow channel 100 of the valve body 1 has a diameter of DN200, and the inner wall of the flow channel 100 is precision machined with a surface roughness Ra≤1.6μm to reduce fluid resistance in the flow channel 100 and prevent impurities in the fluid from depositing on the inner wall of the flow channel 100. A conventional gate 2 drive unit is installed on the top of the valve body 1. This drive unit is electrically driven and includes components such as a motor, reducer, lead screw, and nut. The motor is a Y-series three-phase asynchronous motor with a power of 2.2kW and a speed of 1450r / min. The reducer is a worm gear reducer with a reduction ratio of 50:1. The lead screw and nut are fitted together, and the nut is fixed to the top of the gate 2. When the motor starts, the reducer drives the lead screw to rotate, thereby driving the nut and gate 2 to move up and down, realizing the opening and closing of the flow channel 100. The housing of the drive unit is made of cast steel, which has good protective performance, with a protection level of IP65, and can adapt to harsh environments such as outdoors and humidity. Valve seat structure The valve seat 3 is made of stainless steel (316L), which has excellent corrosion resistance and high temperature resistance, and can adapt to various corrosive fluids and high temperature working conditions. The valve seat 3 has an outer diameter of 250 mm and an inner diameter of 200 mm, which matches the flow channel 100 of the valve body 1. The valve seat 3 is fixed in the flow channel 100 of the valve body 1 by means of flange connection. The nominal pressure of the flange is 1.6 MPa, the flange face adopts a raised face (RF) structure, and an asbestos-rubber gasket is arranged between the sealing faces to ensure the sealing performance between the valve seat 3 and the valve body 1. A blocking groove matched with the bottom end of the gate plate 2 is provided at the bottom of the valve seat 3, and the blocking groove has a width of 20 mm and a depth of 15 mm. The inner wall of the blocking groove is quenched, and the hardness reaches HRC50~55, so as to improve the wear resistance of the blocking groove and prevent wear of the blocking groove caused by repeated insertion and withdrawal of the bottom end of the gate plate 2. Elastic sealing unit Mounting bushing 41: The mounting bushing 41 is made of high-chromium steel, is annular and distributed concentrically with the valve seat 3. The cross section of the mounting bushing 41 is generally shaped like a left-opening glyph, consisting of an axially distributed annular plate A and a radially distributed annular plate B. The mounting bushing 41 can be mounted on the valve seat 3 by means of interference fit or bolt fit. A clamping protrusion 46 is provided on the side wall of the sealing groove 43. The clamping protrusion 46 has a height of 2 mm and a width of 3 mm. An embedding groove 47 is provided on the surface of the clamping protrusion 46, and the embedding groove 47 has a width of 1 mm and a depth of 1 mm. First sealing strip 44: The first sealing strip 44 is made of nitrile rubber, which has good oil resistance, wear resistance and aging resistance. The cross-sectional shape of the first sealing strip 44 matches that of the sealing groove 43, and the first sealing strip 44 has a width of 10 mm and a height of 5 mm. One side of the first sealing strip 44 is provided with a protrusion and a groove that match with the clamping protrusion 46 and the embedding groove 47. Through this matching mode, the first sealing strip 44 can be tightly installed in the sealing groove 43, effectively preventing displacement or falling off during the operation of the gate valve. Supporting seal seat 40: The supporting seal seat 40 is annular and distributed concentrically with the valve seat 3, and is made of chromium-molybdenum steel (40CrMo), which has high strength, toughness and wear resistance. The supporting seal seat 40 has an outer diameter of 240 mm, an inner diameter of 200 mm and a height of 40 mm. The supporting seal seat 40 is radially movably arranged in the seat groove 42.

[0025] Preload spring 45: The preload spring 45 is made of spring steel (60Si2Mn), which has good elasticity and toughness. The preload spring 45 has a diameter of 8mm, a free length of 50mm, a working length of 40mm, and an elastic modulus of 50N / mm. There are 12 preload springs 45, which are evenly distributed around the circumference of the seat groove 42, with an included angle of 30° between two adjacent preload springs 45. One end of the preload spring 45 contacts the bottom of the seat groove 42, and the other end contacts the bottom of the support sealing seat 40. Through the elastic force of the preload spring 45, the support sealing seat 40 can always press the gate plate 2 tightly, ensuring a tight contact between the two. Second sealing strip 6: The second sealing strip 6 is disposed on the outer peripheral surface of the support sealing seat 40 and is made of fluororubber, which has excellent corrosion resistance, high temperature resistance, and aging resistance. The cross-section of the second sealing strip 6 is circular with a diameter of 5mm, and its surface is covered with a coating film 7 with a thickness of 0.5~1mm. The coating film 7 is composed of a water-based polyurethane resin substrate 70 and a silica gel particle filler 71, wherein the water-based polyurethane resin substrate 70 accounts for 70% of the total mass of the coating film 7, and the silica gel particle filler 71 accounts for 30%. The silica gel particle filler 71 is a large-particle filler with a particle size range of 50~100μm, used to increase the surface roughness of the coating film 7 to enhance the sealing effect. Gate and inclined structure The gate 2 is made of wear-resistant cast iron (HT300), which has high strength and wear resistance. The gate 2 is 200mm wide, 300mm high, and 50mm thick. The surface of the gate 2 is precision machined to a surface roughness Ra≤0.8μm to ensure a good sealing fit with the support sealing seat 40.

[0026] The inclined surface 5 is disposed on the surface of the gate 2, including an initial inclined line 50 on the upper part of the gate 2 and an inclined surface extending from the initial inclined line 50 to the bottom end of the gate 2. The initial inclined line 50 is located 50 mm from the top of the gate 2, and the inclined surface extends from the initial inclined line 50 to the bottom end of the gate 2. The inclination angle of the inclined surface 5 is 12°. This angle has been verified through multiple tests and can reduce the contact area between the bottom end of the gate 2 and the bottom of the valve seat 3 while allowing the gate 2 to fit more tightly with the valve seat 3 under back pressure. Work process Gate valve closing process: When the gate valve needs to be closed, the motor of the gate 2 drive unit is started. The motor drives the lead screw to rotate through the reducer, and the nut drives the gate 2 downward under the drive of the lead screw. During the downward movement of the gate 2, the support sealing seat 40 keeps the gate 2 tightly pressed under the action of the preload spring 45 to ensure the seal between the two. When the bottom end of the gate 2 gradually approaches the blocking groove at the bottom of the valve seat 3, the contact area between the bottom end of the gate 2 and the bottom of the valve seat 3 gradually decreases due to the presence of the inclined surface 5, reducing the friction between the two. Finally, the bottom end of the gate 2 is embedded in the blocking groove, and the gate 2 and the valve seat 3 achieve a tight seal through the elastic sealing unit 4, and the flow channel 100 is closed. Operating state under back pressure: When the gate valve is closed and back pressure exists, the fluid applies an upward reverse pressure to the gate 2. Because the gate 2 surface has an inclined section 5, this reverse pressure generates a downward component force along the inclined section. This component force presses the gate 2 against the valve seat 3, thus making the fit between the gate 2 and the valve seat 3 tighter. Simultaneously, the support sealing seat 40, under the action of the preload spring 45, further presses the gate 2, enhancing the sealing effect and effectively preventing the gate 2 from shaking or shifting. Gate valve opening process: When the gate valve needs to be opened, the motor of the gate 2 drive unit is started. The motor reverses, driving the lead screw to rotate in the opposite direction through the reducer. The nut drives the gate 2 to move upward. When the gate 2 moves upward, the support sealing seat 40 remains in contact with the gate 2 under the action of the preload spring 45 until the gate 2 is completely separated from the valve seat 3, and the flow channel 100 is opened. During the opening process, the inclined surface 5 also reduces the contact area between the bottom end of the gate 2 and the bottom of the valve seat 3, reducing wear on the components.

[0027] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A long-life shear gate valve, comprising: Valve body (1), wherein a flow channel (100) and a gate (2) for opening and closing the flow channel (100) are provided inside the valve body (1); Valve seat (3), which is disposed in the flow channel (100) of the valve body (1) for sealing cooperation with the gate (2) to close the flow channel (100); Its characteristic is that it further includes: The elastic sealing unit (4) is disposed on the valve seat (3) and includes a support sealing seat (40) that seals with the gate (2); The inclined surface (5) is disposed on the surface of the gate (2); The inclined surface (5) can reduce the contact area between the bottom of the gate (2) and the bottom of the valve seat (3) and make the gate (2) fit the valve seat (3) more tightly when back pressure is applied.

2. The long-life shear gate valve according to claim 1, characterized in that: The inclined section (5) includes an initial inclined line (50) on the upper part of the gate (2) and an inclined surface extending from the initial inclined line (50) to the bottom end of the gate (2), wherein the inclined angle of the inclined section (5) is 10~15°.

3. A long-life shear gate valve according to claim 2, characterized in that, The elastic sealing unit (4) also includes: Mounting bushing (41) is mounted on valve seat (3). The mounting bushing (41) is made of high chromium steel. A seat groove (42) and a sealing groove (43) are formed between the mounting bushing (41) and valve seat (3). The first sealing strip (44) is disposed in the sealing groove (43); The support sealing seat (40) is radially movable in the seat groove (42), and the support sealing seat (40) presses the gate plate (2) tightly by a pre-tightening spring (45).

4. A long-life shear gate valve according to claim 3, characterized in that: The sealing groove (43) has a snap-fit ​​protrusion (46) on its side wall and an embedding groove (47) on its surface. The first sealing strip (44) is installed in the sealing groove (43) by cooperating with the snap-fit ​​protrusion (46) and the embedding groove (47).

5. A long-life shear gate valve according to claim 3, characterized in that, Also includes: The second sealing strip (6) is disposed on the outer peripheral surface of the support sealing seat (40), and the surface of the second sealing strip (6) is covered with a coating (7).

6. A long-life shear gate valve according to claim 5, characterized in that: The coating (7) is composed of an aqueous polyurethane resin substrate (70) and silicone particle filler (71).

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