Sealing structure of leakage-proof bypass drain valve

Abstract

The invention relates to the technical field of valve sealing, in particular to a sealing structure of a leakage-proof bypass drain valve, which comprises a sealing seat sleeved outside a valve rod, and a packing cavity for inserting packing is formed in the inner side of the top of the sealing seat. An annular packing pad, a lower packing ring, a spacer ring, an upper packing ring and a packing pressing sleeve are sequentially arranged in the packing cavity from bottom to top, a plurality of studs are further arranged on the top face of the sealing seat, and the valve rod is movably sleeved with a packing pressing plate. The spacer ring is arranged between the upper packing ring and the lower packing ring, when the packing pressing plate is pressed downwards, the overall height of the spacer ring can be increased, so that the upper packing ring and the lower packing ring are extruded upwards and downwards correspondingly, and compared with a traditional one-way extrusion mode, the two-way acting force can be transmitted through the spacer ring, and packing stress is uniform.

Description

Technical Field

[0001] This invention relates to the field of valve sealing technology, specifically to a sealing structure for a leak-proof bypass discharge valve. Background Technology

[0002] In industries such as petroleum, chemical, and nuclear power, bypass discharge valves are key components of fluid control, and their sealing performance directly affects production safety and process stability. In these fields, the media are often corrosive, toxic, or subject to high temperatures and pressures. Leakage due to valve seal failure not only wastes resources but can also lead to safety accidents or environmental pollution. Therefore, extremely high requirements are placed on the sealing performance of bypass discharge valves.

[0003] In existing technologies, valve stem sealing structures typically use a sealing seat as the basic component. Specifically, the sealing seat is fitted over the valve stem, and packing material is inserted into the annular gap formed between them. Common packing materials are often flexible sealing materials. To ensure a good seal, pressure is applied to the packing through the cooperation of a packing gland and a packing press plate. The packing gland directly contacts the packing, while the packing press plate provides driving force through bolts or other connecting components, transmitting pressure to the packing gland. This compresses the packing, causing it to deform and fill the gap, thus achieving a seal between the valve stem and the sealing seat.

[0004] However, in existing structures, the compression of the packing by the packing sleeve is a unidirectional action from top to bottom, resulting in a significant uneven stress distribution on the packing. Specifically, the packing near the outer end experiences greater stress because it directly bears the compressive force of the sleeve, while the packing near the inner end experiences less stress due to the reduced compression transmission efficiency. When the compressive force of the packing sleeve is insufficient, the inner packing cannot deform sufficiently, leading to poor sealing. Conversely, when the compressive force is sufficient, the outer packing may become excessively compressed and tightly adhere to the valve stem, creating significant resistance to stem rotation and affecting the valve's operational flexibility. Therefore, we propose a sealing structure for a leak-proof bypass discharge valve to effectively address these drawbacks. Summary of the Invention

[0005] The purpose of this invention is to provide a sealing structure for a leak-proof bypass discharge valve to solve the problems mentioned in the background art.

[0006] This invention is achieved through the following technical solution: a sealing structure for a leak-proof bypass discharge valve, comprising a sealing seat fitted onto the outside of a valve stem, wherein a packing cavity for inserting packing is provided on the inner side of the top of the sealing seat, and an annular packing pad, a lower packing ring, a spacer ring, an upper packing ring, and a packing sleeve are arranged sequentially from bottom to top in the packing cavity; a plurality of studs are also provided on the top surface of the sealing seat; a packing pressure plate is movably fitted onto the outside of the valve stem, and a through hole for the studs to pass through is provided on the packing pressure plate; a clamping nut is threaded onto the top of the studs to ensure that the packing pressure plate and the top of the packing sleeve are tightly abutted together; The spacer ring includes a middle ring, an upper ring, and a lower ring. The upper and lower rings are located on the upper and lower sides of the middle ring, respectively, and the upper and lower rings abut against the bottom surface of the upper packing ring and the top surface of the lower packing ring, respectively. A pressing transmission assembly is provided inside the side wall of the sealing seat. The input end of the pressing transmission assembly extends above the sealing seat. When the packing pressure plate pushes the input end of the pressing transmission assembly downward, the upper annular body and the lower annular body move toward the side away from the middle annular body, respectively.

[0007] Optionally, the number of lower packing rings is four, and the number of upper packing rings is three.

[0008] Optionally, both the lower packing ring and the upper packing ring are made of ceramic fiber or flexible graphite.

[0009] Optionally, the outer surface of the middle annular body is recessed inward with several embedded grooves. Slider blocks are symmetrically arranged on the upper and lower sides inside the embedded grooves. Pushing posts are provided on the opposite sides of the two sliders. The two pushing posts are respectively connected to the upper annular body and the lower annular body.

[0010] Optionally, the slider is hinged with a diagonal brace, and the free ends of the two diagonal braces located in the same inner groove are hinged together with a push block. The push block and the inner wall of the inner groove slide together along the depth direction of the inner groove.

[0011] Optionally, a first guide groove is provided on the inner surface of the packing cavity and at the position directly opposite the embedded groove, and a second guide groove is provided on the top surface of the sealing seat that corresponds one-to-one with the first guide groove. The second guide groove communicates with the first guide groove, and the first guide groove is in the shape of a step with the diameter gradually increasing from the inside to the outside. The pressing transmission assembly includes an abutment post that is movably inserted into the first guide groove. The abutment post and the inner wall of the first guide groove are connected by a return spring. When the return spring is in its natural state, one end of the abutment post extends into the second guide groove, and the other end is located in the first guide groove.

[0012] Optionally, the pressing transmission assembly further includes a pressing column that is vertically inserted into the second guide groove. The pressing column and the sealing seat are elastically connected by a spring. One end of the abutment column extending into the second guide groove is provided with an inclined slot. The bottom end of the pressing column abuts against the inclined surface in the inclined slot. When the pressing column moves downward, the abutment column can move toward the side closer to the packing cavity.

[0013] Optionally, a sealing sheet is glued to one end of the first guide groove near the packing cavity, and the sealing sheet is made of an elastic material.

[0014] Optionally, the packing sleeve includes a lower sleeve and an upper sleeve, which are elastically connected vertically.

[0015] Optionally, the lower pressure sleeve is a two-stage stepped shaft with an outer diameter that gradually increases from bottom to top, and the bottom diameter of the lower pressure sleeve is adapted to the inner diameter of the packing cavity. In the sealed state, the lower edge of the top of the lower pressure sleeve abuts against the top surface of the sealing seat.

[0016] Compared with the prior art, the present invention provides a sealing structure for a leak-proof bypass discharge valve, which has the following advantages: 1. The present invention provides a spacer ring between the upper packing ring and the lower packing ring. When the packing pressure plate is pressed down, the overall height of the spacer ring can increase, thereby squeezing the upper packing ring and the lower packing ring upward and downward respectively. Compared with the traditional unidirectional squeezing method, the present invention can transmit bidirectional force through the spacer ring, which helps to make the packing uniformly stressed. 2. The present invention includes a pressing transmission assembly, which is used to convert the downward pressure of the packing plate into a force that drives the height of the spacer ring to increase. The pressing transmission assembly is located outside the packing cavity. Therefore, the setting of the pressing transmission assembly can not only realize the transmission of force, but also will not cause a decrease in the sealing performance of the valve. 3. The packing sleeve in this invention has its own elasticity, and the position of the lower packing sleeve can be fixed after the lower packing sleeve abuts against the top surface of the sealing seat. Therefore, this invention can increase the height of the spacer ring alone without changing the position of the lower packing sleeve, so that the upper packing ring and the lower packing ring are subjected to uniform force. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional view of the sealing seat structure according to Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the spacer ring structure of the present invention; Figure 4 This is a schematic diagram of the packing sleeve structure according to Embodiment 1 of the present invention; Figure 5This is a schematic diagram of the abutment column structure of the present invention; Figure 6 for Figure 2 Enlarged view of point A in the middle; Figure 7 This is a cross-sectional view of the sealing seat structure according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the packing sleeve structure in Embodiment 2 of the present invention; Figure 9 for Figure 7 Enlarged view of the corresponding area at point B.

[0018] In the diagram: 100, valve stem; 200, sealing seat; 201, stud; 202, first guide groove; 203, second guide groove; 300, packing pad; 400, lower packing ring; 500, spacer ring; 501, middle annular body; 502, upper annular body; 503, lower annular body; 504, inner groove; 505, slider; 506, push post; 507, diagonal brace; 508, push block; 600, upper packing ring; 700, packing sleeve; 701, lower sleeve; 702, upper sleeve; 703, guide rod; 800, packing pressure plate; 900, clamping transmission assembly; 901, abutment post; 902, sealing plate; 903, return spring; 904, oblique groove; 905, pressing post. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: Please refer to Figure 1 - Figure 6 This application proposes a sealing structure for a leak-proof bypass discharge valve, including a sealing seat 200 fitted around the valve stem 100. The sealing seat 200 has a packing cavity on its inner top for inserting packing material. The packing cavity is annular in shape, and from bottom to top, it contains an annular packing pad 300, a lower packing ring 400, a spacer ring 500, an upper packing ring 600, and a packing sleeve 700. The top surface of the sealing seat 200 also has several studs 201. A packing pressure plate 800 is movably fitted around the valve stem 100. The packing pressure plate 800 has through holes through which the studs 201 pass. A clamping nut is threaded onto the top of each stud 201 to ensure tight contact between the packing pressure plate 800 and the top of the packing sleeve 700. Therefore, by rotating the clamping nut, the packing pressure plate 800 can be driven to press down, thereby compressing the packing ring and achieving a sealing effect.

[0021] It should be noted that there are four lower packing rings 400 and three upper packing rings 600. Both the lower packing rings 400 and the upper packing rings 600 are made of ceramic fiber or flexible graphite, both of which have high-temperature resistance properties, thus enabling long-term use under high-temperature and high-pressure environments. Furthermore, the bottom end of the packing sleeve 700 extends into the packing cavity, and its top end is located above the sealing seat 200 and abuts against the packing pressure plate 800.

[0022] Furthermore, the spacer ring 500 includes a middle ring 501, an upper ring 502, and a lower ring 503. The upper ring 502 and the lower ring 503 are located on the upper and lower sides of the middle ring 501, respectively, and the upper ring 502 and the lower ring 503 abut against the bottom surface of the upper packing ring 600 and the top surface of the lower packing ring 400, respectively. The middle ring 501, the upper ring 502, and the lower ring 503 are all made of stainless steel, which has good structural strength and high temperature resistance and wear resistance.

[0023] In order to allow the upper annular body 502 and the lower annular body 503 to extend upward and downward to compress the packing, this embodiment also has the following design: A pressing transmission assembly 900 is provided inside the side wall of the sealing seat 200. The input end of the pressing transmission assembly 900 extends above the sealing seat 200. When the packing pressure plate 800 pushes the input end of the pressing transmission assembly 900 downward, the upper annular body 502 and the lower annular body 503 move towards the side away from the middle annular body 501. That is, the pressing transmission assembly 900, as a power transmission mechanism, can convert the downward pressure of the packing pressure plate 800 into the force of separation between the upper annular body 502 and the lower annular body 503.

[0024] The outer surface of the middle annular body 501 is recessed inward and has several embedded grooves 504. Specifically, in this embodiment, there are four embedded grooves 504. Slider blocks 505 are symmetrically arranged on the upper and lower sides inside the embedded grooves 504. Pushing posts 506 are provided on the back side of each slider 505. The two pushing posts 506 are respectively connected to the upper annular body 502 and the lower annular body 503. Specifically, the top wall and bottom wall of the middle annular body 501 have shaft holes for the pushing posts 506 to pass through. The pushing posts 506 and the upper annular body 502 / lower annular body 503 can be integrally formed. One end of the pushing post 506 located in the embedded groove 504 has external threads, and the pushing post 506 passes through the corresponding slider 505 and is locked and fixed by a nut.

[0025] It is worth mentioning that the inner wall of the recessed groove 504 also has vertically distributed slide rails, and the slider 505 slides in engagement with these slide rails to improve the stability of the slider 505. In addition, a diagonal brace 507 is hinged to the slider 505, and the free ends of two diagonal braces 507 located in the same recessed groove 504 are hinged to a pushing block 508. The pushing block 508 slides in engagement with the inner wall of the recessed groove 504 along the depth direction of the recessed groove 504. A groove is formed on the inner wall of the recessed groove 504 along its own depth direction, and the pushing block 508 slides in engagement with this groove to enhance the stability of the pushing block 508.

[0026] In addition, a first guide groove 202 is provided on the inner surface of the packing cavity and at the position directly opposite the embedded groove 504. A second guide groove 203 corresponding to the first guide groove 202 is provided on the top surface of the sealing seat 200. The first guide groove 202 is horizontally distributed and the second guide groove 203 is vertically distributed. The second guide groove 203 communicates with the first guide groove 202 and the two cooperate to form an L-shaped through groove. The first guide groove 202 has a stepped shape with the diameter gradually increasing from the inside to the outside. Furthermore, the pressing transmission assembly 900 includes an abutment post 901 that is movably inserted into the first guide groove 202. The diameter of the abutment post 901 is adapted to the inner diameter of the thinnest part of the first guide groove 202, and the cross-section of the abutment post 901 is a rounded rectangle.

[0027] In this embodiment, a sealing sheet 902 is glued to one end of the first guide groove 202 and near the packing cavity. The sealing sheet 902 is made of an elastic material, such as fluororubber, which has a certain degree of extensibility and high temperature resistance. Its function is to prevent the medium in the valve body from entering the first guide groove 202 and ensure the sealing effect.

[0028] like Figure 6 As shown, the abutment post 901 and the inner wall of the first guide groove 202 are connected by a return spring 903. Specifically, the return spring 903 is sleeved on the outside of the abutment post 901, with one end of the return spring 903 glued to the inner wall of the first guide groove 202 and the other end glued to the inner edge of the outer end of the abutment post 901. Furthermore, high-temperature silicone adhesive can be used for bonding, which can maintain good fixing effect even in high-temperature environments.

[0029] When the return spring 903 is in its natural state, it is not subject to external force. At this time, one end of the abutment post 901 extends into the second guide groove 203, and the other end is located in the first guide groove 202. The end of the abutment post 901 that extends into the second guide groove 203 is provided with a slanted slot 904, which is directly opposite the top of the second guide groove 203.

[0030] In this embodiment, the pressing transmission assembly 900 further includes a pressing column 905 that is vertically inserted into the second guide groove 203. The pressing column 905 is elastically connected to the sealing seat 200 by a spring. The two ends of the spring are welded and fixed to the top surface of the sealing seat 200 and the lower edge of the top end of the pressing column 905, respectively. Furthermore, the bottom end of the pressing column 905 abuts against the inclined surface in the inclined slot 904. When the pressing column 905 moves downward, the abutting column 901 can move toward the side closer to the packing cavity.

[0031] In summary, during the assembly process of this embodiment, the packing gasket 300, lower packing ring 400, spacer ring 500, upper packing ring 600, and packing sleeve 700 are sequentially inserted into the packing cavity. It should be noted that since the lower packing ring 400 / upper packing ring 600 are annular rings formed by strips of material, the joints of adjacent lower packing rings 400 / upper packing rings 600 must be staggered. Furthermore, in this initial state, the top of the packing sleeve 700 is higher than the top of the pressing post 905.

[0032] Then, the packing pressure plate 800 is placed on the outside of the valve stem 100, and the packing pressure plate 800 is driven to press down by continuously tightening the clamping nut. At first, the packing pressure plate 800 will push the packing sleeve 700 down, and the packing sleeve 700 will squeeze the upper packing ring 600, the lower packing ring 400 and the spacer ring 500 downward. Subsequently, the packing pressure plate 800 also abuts against the pressing column 905 and pushes the pressing column 905 down. Under the action of the pressing column 905, the abutting column 901 extends outward and squeezes the pushing block 508 inward. At the same time, the upper annular body 502 and the lower annular body 503 move to the upper and lower sides respectively, further squeezing the upper packing ring 600 and the lower packing ring 400.

[0033] Because traditional packing sleeves 700 can only compress the packing rings from top to bottom, resulting in uneven stress on several packing rings; however, in this embodiment, the upper packing ring 600 can be subjected to extrusion forces from both the upper and lower sides at the same time, while the lower packing ring 400 can also be subjected to downward pressure, thus helping to make the stress on several packing rings more uniform, thereby helping to improve the packing sealing effect.

[0034] Example 2: Please refer to Figure 7 - Figure 9 This application also proposes a sealing structure for a leak-proof bypass discharge valve. The difference between this embodiment and Embodiment 1 is that the packing sleeve 700 includes a lower sleeve 701 and an upper sleeve 702, which are elastically connected vertically. Specifically, the bottom surface of the upper sleeve 702 is provided with a guide rod 703, the top surface of the lower sleeve 701 is provided with a guide hole for the guide rod 703 to be inserted, and a spring is also sleeved on the outside of the guide rod 703, with both ends of the spring abutting against the lower sleeve 701 and the upper sleeve 702 respectively.

[0035] Furthermore, the lower pressure sleeve 701 is a two-stage stepped shaft with an outer diameter that gradually increases from bottom to top, and the bottom diameter of the lower pressure sleeve 701 is adapted to the inner diameter of the packing cavity. In the sealed state, the lower edge of the top of the lower pressure sleeve 701 abuts against the top surface of the sealing seat 200.

[0036] In summary, during the actual assembly process of this embodiment, after the packing pad 300, lower packing ring 400, spacer ring 500, upper packing ring 600, and packing sleeve 700 are sequentially inserted into the packing cavity, the lower edge of the top of the lower sleeve 701 does not contact the sealing seat 200, and the top of the upper sleeve 702 is also higher than the top of the pressing column 905. As the packing pressure plate 800 moves downward, firstly, the packing pressure plate 800 abuts against the upper sleeve 702 and pushes the packing sleeve 700 downward as a whole. During this process, the upper packing ring 600, spacer ring 500, and lower packing ring 400 will also move downward.

[0037] When the lower edge of the top of the lower pressure sleeve 701 abuts against the top surface of the sealing seat 200, the position of the lower pressure sleeve 701 is fixed and no longer moves. As the packing pressure plate 800 continues to move downward, the packing pressure plate 800 will abut against the top of the pressing column 905, and indirectly push the upper annular body 502 and the lower annular body 503 to move in opposite directions, thereby squeezing the upper packing ring 600 and the lower packing ring 400.

[0038] The difference between this embodiment and Embodiment 1 is that: firstly, the upper packing ring 600 and the lower packing ring 400 are initially compressed by the packing sleeve 700, and then the upper packing ring 600 and the lower packing ring 400 are squeezed from the middle to both sides respectively. The purpose is to make the compression amplitude of the upper packing ring 600 and the lower packing ring 400 equal, so as to avoid the upper packing ring 600 being squeezed too much or the lower packing ring 400 being squeezed too little.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A sealing structure for a leak-proof bypass discharge valve, comprising a sealing seat fitted onto the outside of the valve stem, characterized in that: The sealing seat has a packing cavity for inserting packing material on its top inner side. The packing cavity contains, from bottom to top, an annular packing pad, a lower packing ring, a spacer ring, an upper packing ring, and a packing sleeve. The top surface of the sealing seat is also provided with several studs. A packing pressure plate is movably fitted on the outside of the valve stem. The packing pressure plate has a through hole for the studs to pass through. The top of the studs is threaded with a clamping nut so that the packing pressure plate and the top of the packing sleeve are tightly abutted together. The spacer ring includes a middle ring, an upper ring, and a lower ring. The upper and lower rings are located on the upper and lower sides of the middle ring, respectively, and the upper and lower rings abut against the bottom surface of the upper packing ring and the top surface of the lower packing ring, respectively. A pressing transmission assembly is provided inside the side wall of the sealing seat. The input end of the pressing transmission assembly extends above the sealing seat. When the packing pressure plate pushes the input end of the pressing transmission assembly downward, the upper annular body and the lower annular body move toward the side away from the middle annular body, respectively.

2. The sealing structure of the leak-proof bypass discharge valve according to claim 1, characterized in that: The number of lower packing rings is four, and the number of upper packing rings is three.

3. The sealing structure of the leak-proof bypass discharge valve according to claim 1, characterized in that: Both the lower and upper packing rings are made of ceramic fiber or flexible graphite.

4. The sealing structure of a leak-proof bypass discharge valve according to any one of claims 1-3, characterized in that: The outer surface of the middle annular body is recessed inward and has several embedded grooves. Slider blocks are symmetrically arranged on the upper and lower sides of the inner surface of the embedded grooves. Pushing posts are provided on the opposite sides of the two sliders. The two pushing posts are respectively connected to the upper annular body and the lower annular body.

5. The sealing structure of the leak-proof bypass discharge valve according to claim 4, characterized in that: The slider is hinged with a diagonal brace, and the free ends of the two diagonal braces located in the same inner groove are hinged together with a push block. The push block and the inner wall of the inner groove slide together along the depth direction of the inner groove.

6. The sealing structure of the leak-proof bypass discharge valve according to claim 5, characterized in that: The inner surface of the packing cavity is provided with a first guide groove at the position directly opposite the inner groove. The top surface of the sealing seat is provided with a second guide groove that corresponds to the first guide groove. The second guide groove is connected to the first guide groove. The first guide groove is in the shape of a step with the diameter gradually increasing from the inside to the outside. The pressing transmission assembly includes an abutment post that is movably inserted into the first guide groove. The abutment post and the inner wall of the first guide groove are connected by a return spring. When the return spring is in its natural state, one end of the abutment post extends into the second guide groove, and the other end is located in the first guide groove.

7. The sealing structure of the leak-proof bypass discharge valve according to claim 6, characterized in that: The pressing transmission assembly also includes a pressing column that is vertically inserted into the second guide groove. The pressing column and the sealing seat are elastically connected by a spring. One end of the abutment column extending into the second guide groove is provided with an inclined slot. The bottom end of the pressing column abuts against the inclined surface in the inclined slot. When the pressing column moves downward, the abutment column can move toward the side closer to the packing cavity.

8. The sealing structure of the leak-proof bypass discharge valve according to claim 6, characterized in that: A sealing sheet is glued to one end of the first guide groove near the packing cavity, and the sealing sheet is made of elastic material.

9. The sealing structure of a leak-proof bypass discharge valve according to claim 1 or 7, characterized in that: The packing sleeve includes a lower sleeve and an upper sleeve, which are elastically connected vertically.

10. The sealing structure of a leak-proof bypass discharge valve according to claim 9, characterized in that: The lower pressure sleeve is a two-stage stepped shaft with an outer diameter that gradually increases from bottom to top, and the bottom diameter of the lower pressure sleeve is adapted to the inner diameter of the packing cavity. In the sealed state, the lower edge of the top of the lower pressure sleeve abuts against the top surface of the sealing seat.

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