A zero-leakage butterfly valve

Abstract

This invention relates to a zero-leakage butterfly valve. The butterfly valve includes a valve body, a valve stem, and a disc. The valve body has a valve seat, and the outer circumferential surface of the disc is provided with a sealing structure. The valve seat has a sealing mating surface. The sealing structure includes an inflatable air bladder disposed on the outer circumferential surface of the disc. The inflatable air bladder is connected to an air source via an air passage. The inflatable air bladder has a sealing position where it contacts and seals with the valve seat after inflation, and a disengaging position where it detaches from the valve seat after deflating. At least two annular protrusions are spaced apart along the axial direction on the sealing mating surface of the valve seat. When the inflatable air bladder is in the sealing position, its outer surface contacts and seals with at least two annular protrusions, forming two or more sealing layers. Through the above means, zero leakage is achieved with the butterfly valve, replacing existing valve assemblies composed of two or more valves, which not only occupies less space but also significantly reduces operating costs.

Description

Technical Field

[0001] This invention relates to the field of valves, and more specifically to a zero-leakage butterfly valve. Background Technology

[0002] A butterfly valve is a simple on / off valve used to control the flow of various types of fluids, including air, water, steam, corrosive media, slurry, oil, liquid metals, and radioactive media. Its main functions are shut-off and throttling. A butterfly valve mainly consists of a valve body, a valve stem, and a disc. A valve seat is located on the valve body, and a sealing pair is formed between the valve seat and the disc. Existing sealing pairs are generally hard-seal metal layers on the outer circumference of the disc. While this sealing method is wear-resistant, its sealing effect is poor and it cannot be used in conditions requiring high sealing performance. For example, when used with highly toxic gas media, the valve needs to ensure absolute zero leakage. In this case, hard metal seals cannot meet the requirements, and only soft seal structures, such as solid rubber sealing rings, can be used. Zero leakage is achieved by interfering with and compressing the soft sealing ring, but this method causes significant friction and damage to the soft sealing ring, resulting in a shorter service life.

[0003] To ensure zero leakage under special operating conditions, multiple valves are typically used in combination to form valve assemblies. However, these assemblies are large, expensive, and wasteful of space and money. Therefore, there is an urgent need in the market for a zero-leakage butterfly valve that is simple in structure, low in cost, and small in size to replace the existing valve assemblies. Summary of the Invention

[0004] The purpose of this invention is to provide a zero-leakage butterfly valve to solve the problems of large space occupation and high cost caused by using valve assemblies to achieve zero leakage in the prior art.

[0005] To achieve the above objectives, the present invention provides a zero-leakage butterfly valve with the following technical solution: A zero-leakage butterfly valve includes a valve body, a valve stem, and a disc. The valve body has a valve seat, and a sealing structure is provided on the outer circumferential surface of the disc. The valve seat has a sealing mating surface that seals with the sealing structure. The sealing structure includes an inflatable airbag disposed on the outer circumferential surface of the disc. The inflatable airbag is connected to a gas source through a gas passage. The inflatable airbag has a sealing position that contacts and seals with the valve seat after inflation, and the pressure of the injected gas is greater than the pressure of the gas medium in the pipeline. The inflatable airbag also has a disengagement position that separates from the valve seat after deflating to avoid interference and friction between the inflatable airbag and the valve seat during the disc rotation and opening process. At least two annular protrusions are spaced apart along the axial direction on the sealing mating surface of the valve seat. When the inflatable airbag is in the sealing position, its outer surface contacts and seals with at least two annular protrusions to form more than two sealing layers.

[0006] The disc plate has an annular mounting groove on its outer circumferential surface. The two side walls of the annular mounting groove have slots. The inflatable airbag has a mounting part that is installed in the annular mounting groove. The two sides of the mounting part have locking protrusions that engage with the slots. The air passage includes a first air passage provided on the disc plate. The first air passage has an air port at the bottom of the annular mounting groove. The inflatable airbag has a gas channel that communicates with the air port.

[0007] There are multiple slots on each side, spaced apart circumferentially. The mounting part of the inflatable airbag has multiple such locking protrusions, each locking protrusion corresponding to a slot. The gas channel is an air hole that communicates with the cavity of the inflatable airbag. The number of air holes is the same as the number of air inlets, and they are arranged in a one-to-one correspondence. The air holes are connected to the corresponding air inlets through the installation and cooperation of the corresponding slots and locking protrusions.

[0008] Each side has an annular slot, and the gas channel is an annular channel that connects to the cavity of the inflatable airbag.

[0009] The bottom of the annular mounting groove is provided with an annular positioning groove with a conical cross-section. The air inlet is located on the bottom of the positioning groove. The mounting part of the inflatable airbag has a conical positioning part that is positioned and matched with the positioning groove.

[0010] The disc plate includes a separate plate body and an annular pressure plate. The plate body has a step, and the annular pressure plate and the step together form the annular mounting groove.

[0011] The air passage also includes a second air passage disposed on the valve stem, and the air passage also includes a connecting air pipe connecting the first air passage and the second air passage.

[0012] The beneficial effects of this invention are as follows: When the disc is rotated to the closed position, air is injected into the cavity of the inflatable bladder through an air source, causing the outer circumference of the inflatable bladder to bulge and contact at least two annular protrusions on the sealing mating surface of the valve seat for a sealing fit. This structure directly forms at least two sealing layers, replacing existing valve assemblies composed of two or more valves, which not only occupies less space but also significantly reduces operating costs. Before the disc is opened, air is first deflated from the inflatable bladder to disengage the sealing mating surface between the inflatable bladder and the valve seat, preventing friction between the inflatable bladder and the valve seat during the disc's rotation to the open position, thus avoiding a reduction in the inflatable bladder's service life. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of one embodiment of a zero-leakage valve of the present invention;

[0014] Figure 2 yes Figure 1 Internal structure diagram of a zero-leakage valve;

[0015] Figure 3 yes Figure 2 A magnified view of a section at point A in the middle;

[0016] Figure 4 yes Figure 3 A magnified view of a section at point B. Detailed Implementation

[0017] An embodiment of a zero-leakage valve of the present invention, such as... Figures 1-4 As shown, the valve includes a valve body 1, a valve stem 2, and a disc 3. The valve body has a valve seat 4. In this embodiment, the valve seat is a fixed valve seat and is integrally formed on the valve body. A sealing structure is provided on the outer peripheral surface of the disc, and the valve seat has a sealing mating surface that seals with the sealing structure. Specifically, in this embodiment, the sealing structure includes an inflatable airbag 8 disposed on the outer peripheral surface of the disc 3. The inflatable airbag 8 is connected to an air source through an air passage. The air source can be an air tank or an air pump. A pressure gauge and a control valve are provided on the air passage.

[0018] The inflatable airbag 8 has a sealing position that, after inflation, contacts and seals with the valve seat. The pressure of the injected gas must be greater than the pressure of the gas medium in the valve pipeline to ensure a seal. The inflatable airbag also has a disengagement position that detaches from the valve seat after deflating. After deflating, the inflatable airbag shrinks and disengages from the valve seat, preventing interference and friction between the inflatable airbag and the valve seat during the disc rotation opening process. Friction can cause scratches or thinning of the inflatable airbag surface, reducing its service life. At least two annular protrusions 9 are spaced apart along the axial direction on the sealing surface of the valve seat. When the inflatable airbag is in the sealing position, its outer surface contacts and seals with at least two annular protrusions, forming two or more sealing layers. In this embodiment, when the inflatable airbag is in the sealing position, its outer surface contacts and seals with two annular protrusions, forming a double seal.

[0019] The inflatable airbag is installed as follows: An annular mounting groove is provided on the outer circumferential surface of the disc plate 3. Slots 13 are provided on both sides of the groove. The inflatable airbag has a mounting portion installed in the annular mounting groove. Slot protrusions 14 are provided on both sides of the mounting portion to engage with the slots. The air passage includes a first air passage 5 provided on the disc plate. The first air passage has an air port 18 at the bottom of the annular mounting groove. The inflatable airbag has a gas channel 17 communicating with the air port. Specifically, each slot 13 is an annular slot, and the gas channel 17 is an annular channel communicating with the cavity 12 of the inflatable airbag. An annular positioning groove 15 with a conical cross-section is provided at the bottom of the annular mounting groove. The mounting portion of the inflatable airbag has a conical positioning portion 16 that engages with the positioning groove. At this time, the air port is located at the bottom of the positioning groove. To facilitate the assembly and disassembly of the inflatable airbag, in this embodiment, the disc plate includes a separate plate body and an annular pressure plate 15, which are connected together by screws. A step is provided on the plate body, and the annular pressure plate and the step together form the aforementioned annular mounting groove. One slot is provided on the vertical surface of the step, and the other slot is provided on the annular pressure plate. The air passage also includes a second air passage 6 disposed on the valve stem, and a connecting air pipe 7 connecting the first air passage and the second air passage. The connecting air pipe can be made of metal.

[0020] During operation, the disc is rotated to the closed position. Gas is injected into the inflatable bladder at a pressure greater than the pressure of the gas medium inside the valve pipeline. This causes the outer circumference of the inflatable bladder to bulge and contact the two annular protrusions on the sealing surface of the valve seat, forming a double seal to ensure zero leakage of the valve. Before opening, the inflatable bladder is evacuated to disengage the sealing surface between the inflatable bladder and the valve seat, preventing friction between the inflatable bladder and the valve seat during the rotation of the disc from the closed to the open position.

[0021] In other embodiments of the present invention, when the inflatable airbag is in the sealed position, its outer surface can be configured to contact and seal with three or more annular protrusions as needed, thereby forming a double triple seal or a multi-layer seal; the connecting air tube can also be a plastic tube depending on the actual working conditions; the gas channel can also be configured not as annular, or it can be configured as an air hole communicating with the cavity of the inflatable airbag. In this case, there are multiple slots on each side, which are spaced apart circumferentially. The mounting part of the inflatable airbag is provided with multiple of the above-mentioned locking protrusions, and each locking protrusion is configured to correspond one-to-one with the corresponding slot. The number of air holes is the same as the number of air inlets, which are configured one-to-one. The air holes and corresponding air inlets are connected by the installation and cooperation of the corresponding slots and locking protrusions.

Claims

1. A zero-leakage butterfly valve, comprising a valve body, a valve stem, and a disc, wherein the valve body has a valve seat, the outer circumferential surface of the disc is provided with a sealing structure, and the valve seat has a sealing mating surface that seals with the sealing structure, characterized in that: The sealing structure includes an inflatable airbag disposed on the outer peripheral surface of the disc plate. The inflatable airbag is connected to an air source via an air passage. The inflatable airbag has a sealing position that, after inflation, contacts and seals with the valve seat, and the pressure of the injected gas is greater than the pressure of the gas medium in the pipeline. The inflatable airbag also has a disengagement position that, after deflating, separates from the valve seat to prevent interference and friction between the inflatable airbag and the valve seat during the disc plate rotation and opening process. The sealing mating surface of the valve seat has at least two annular protrusions spaced along its axial direction. When the inflatable airbag is in the sealing position, its outer surface contacts at least two annular protrusions. The contact seal forms two or more sealing layers; there are multiple slots on each side, spaced circumferentially; the mounting part of the inflatable airbag has multiple locking protrusions, each locking protrusion corresponding to a slot; the gas channel is an air hole communicating with the airbag cavity; the number of air holes is the same as the number of air inlets, and they are arranged in a one-to-one correspondence; the air hole communicates with the corresponding air inlet through the installation and cooperation of the corresponding slot and locking protrusion; the slots on each side are annular slots, and the gas channel is annular and communicates with the airbag cavity.

2. The zero-leakage butterfly valve according to claim 1, characterized in that: The disc plate has an annular mounting groove on its outer circumferential surface. The two side walls of the annular mounting groove have slots. The inflatable airbag has a mounting part that is installed in the annular mounting groove. The two sides of the mounting part have locking protrusions that engage with the slots. The air passage includes a first air passage on the disc plate. The first air passage has an air port at the bottom of the annular mounting groove. The inflatable airbag has a gas channel that communicates with the air port.

3. The zero-leakage butterfly valve according to claim 2, characterized in that: The bottom of the annular mounting groove is provided with an annular positioning groove with a conical cross-section. The air inlet is located on the bottom of the positioning groove. The mounting part of the inflatable airbag has a conical positioning part that is positioned and matched with the positioning groove.

4. The zero-leakage butterfly valve according to claim 2, characterized in that: The disc plate includes a separate plate body and an annular pressure plate. The plate body has a step, and the annular pressure plate and the step together form the annular mounting groove.

5. The zero-leakage butterfly valve according to any one of claims 2-4, characterized in that: The air passage also includes a second air passage disposed on the valve stem, and the air passage also includes a connecting air pipe connecting the first air passage and the second air passage.

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