A self-sealing butterfly valve

Abstract

The invention discloses a self-sealing butterfly valve, the sealing of which has two seals, a sealing structure 1 and a sealing structure 2, wherein the sealing structure 1 is a main seal and the sealing structure 2 is a transition seal before the valve plate is closed and rotated into place. The sealing ability is improved as the medium pressure in the valve body increases, the sealing is more reliable, and no other pressurizing equipment is needed.

Description

Technical Field

[0001] The invention relates to the field of valves, and in particular to a self-sealing butterfly valve. Background Art

[0002] Butterfly valve, also known as flap valve, can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. Butterfly valve is a simple regulating valve. The opening and closing part of the butterfly valve is a disc-shaped valve plate, which rotates around the center line of the valve stem in the valve body to achieve the purpose of opening, closing or regulating.

[0003] The sealing of the existing butterfly valve after closing is achieved by the pre-interference amount of the rubber sealing ring and the valve body, which causes a large torque when the valve is opened and closed. Therefore, when selecting a drive device, a larger drive device must be selected to open and close the valve. In addition to causing inconvenience to the operation, the price of the entire product is also relatively high, and it also causes a waste of resources.

[0004] In Chinese utility model patent ZL200920063651.X, a fluid pressure sealing butterfly valve is disclosed, which has an annular groove on the outer edge of the valve plate, and an annular expansion piston in the annular groove. When the gate is closed, the annular expansion piston in the annular groove is pressed against the inner wall of the valve body under the action of fluid pressure to ensure the sealing of the gate and the valve body. Although this technology solves the disadvantages of the pre-interference between the rubber sealing ring and the valve body, since the expansion of the annular expansion piston takes time, the valve is not closed tightly after the valve plate rotates and closes and before the annular expansion piston expands, resulting in unnecessary waste of the medium. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a self-sealing butterfly valve which can achieve rapid and complete sealing when the valve plate is closed.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A self-sealing butterfly valve comprises a valve body, a valve stem and a valve plate. The valve stem is rotatably fixed to the valve body, and one end of the valve stem is connected to a power unit that drives the valve stem to rotate. The valve plate is located in the valve body and fixed to the valve stem. When the butterfly valve is in a closed state, the valve plate separates the inner cavity of the valve body into an independent water inlet cavity and a water outlet cavity in the axial direction. The valve plate is characterized in that:

[0008] A sealing structure 1 is provided between the outer edge of the valve plate and the inner wall of the valve body, and the sealing structure 1 includes:

[0009] A sealing ring 1 is embedded on the inner wall of the valve body. The sealing ring 1 is a hollow structure. The inner cavity of the sealing ring 1 is connected with the water inlet cavity through a water inlet pipe with a control valve 1. After the sealing ring 1 expands, it is in close contact with the outer edge of the valve plate.

[0010] A second sealing structure is provided between the outer edge of the valve plate and the inner wall of the valve plate, and the second sealing structure includes:

[0011] A limit stopper, the limit stopper comprising two semi-ring pieces fixed on the inner wall of the valve body, the two semi-ring pieces being symmetrical with the valve stem as the center and staggered along the axial direction, for limiting the rotation of the valve plate after closing; and

[0012] The second sealing ring is embedded in the side of the limit stopper facing the valve plate. The second sealing ring is also a hollow structure. The second sealing ring is connected to the first sealing ring through a pressure equalizing pipe with a control valve.

[0013] A further technical solution is that the centers of the two ends of the sealing ring are eccentrically arranged, and the valve plate has a contact surface that matches the sealing ring, so that a wedge-shaped extrusion seal is formed between the valve plate and the sealing ring, and when the valve plate is rotated to open, the wedge-shaped surface between the valve plate and the sealing ring is misaligned, so that the valve plate can squeeze the sealing ring.

[0014] A further technical solution is that a sealing coating is coated on a sealing surface of the valve plate in contact with the sealing ring.

[0015] A further technical solution is that the inner cavity of the sealing ring 1 is also connected to the water outlet cavity through a water outlet pipe with a control valve 3, and a pressure gauge is provided on the water inlet pipe.

[0016] A further technical solution is to further include:

[0017] The controller has a signal input end connected to the power unit, and a control output end connected to control valve 1 and control valve 2.

[0018] A further technical solution is that the valve stem comprises:

[0019] The upper shaft has a lower end inserted into the vertical center hole of the valve plate and fixed by a transverse pin, and an upper end extending out of the valve body and provided with a rotary seal between the valve body; and

[0020] The upper end of the lower shaft is inserted into the vertical center hole of the valve plate and is fixed by a transverse pin shaft, and the lower end of the lower shaft is rotatably connected to the valve body.

[0021] A further technical solution is that the rotary seal comprises:

[0022] The sealing packing is spirally wound on the upper shaft. A boss for positioning the sealing packing downward is provided on the valve body, and a packing gland is provided above the sealing packing.

[0023] The beneficial effects of adopting the above technical solution are:

[0024] The butterfly valve has two seals: seal structure 1 and seal structure 2. Seal structure 1 is the main seal, and seal structure 2 is the transition seal before the valve plate is closed and rotated into place. The sealing ability increases with the increase of the medium pressure in the valve body, and the seal is more reliable, without the need to use other pressurizing equipment.

[0025] When the butterfly valve is in the closed state, the control valve 2 is closed, the sealing ring 2 does not expand, the control valve 1 is opened, the high-pressure medium in the water inlet chamber enters the sealing ring 1 through the water inlet pipe, the sealing ring 1 expands and squeezes the valve plate, thereby achieving sealing between the sealing ring 1 and the outer edge of the valve plate;

[0026] When the butterfly valve needs to be opened, control valve 1 is closed and control valve 2 is opened. The medium in seal ring 1 flows into seal ring 2 through the pressure equalizing pipe, seal ring 2 expands, and seal ring 1 contracts after pressure relief. When the power unit drives the valve plate to rotate, the friction between the valve plate and the seal ring is small, thus avoiding the use of high-power drive devices.

[0027] When the butterfly valve needs to be closed, control valve one is closed and control valve two is opened. When the valve plate is about to rotate into place, it will squeeze the expanded sealing ring two, and the medium in the sealing ring two will return to the sealing ring one again. In this process, the sealing of the butterfly valve is achieved through the valve plate and the sealing ring two. The setting of the sealing ring two avoids the delay of the butterfly valve closing and the outflow of the medium caused by the slow sealing response speed between the valve plate and the sealing ring.

[0028] When the valve plate is rotated into position, control valve two is closed and control valve one is opened. At this time, the medium in sealing ring two is completely returned to sealing ring one. At this time, the sealing of the butterfly valve is achieved through the valve plate and sealing ring one, and the sealing between sealing ring two and the valve plate fails after shrinkage, and the valve plate will not be squeezed, ensuring the stability of the closed state after the valve plate is rotated into position. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0030] Figure 1 It is a schematic diagram of the main structure of the butterfly valve in the present invention;

[0031] Figure 2 It is a left-side structural schematic diagram of the butterfly valve in the present invention;

[0032] Figure 3 yes Figure 1 Schematic diagram of the structure of the medium BB;

[0033] Figure 4 yes Figure 1 Schematic diagram of the structure of AA;

[0034] Figure 5 yes Figure 4 Schematic diagram of the enlarged structure of part D. DETAILED DESCRIPTION

[0035] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0037] like Figure 1 to Figure 5 As shown, a specific embodiment of a self-sealing butterfly valve disclosed in the present invention includes a valve body 1, a valve stem and a valve plate 2. The valve stem is rotatably fixed on the valve body 1, and one end of the valve stem is connected to a power unit 31 for driving its rotation, such as a worm head. The valve plate 2 is located in the valve body 1 and fixed to the valve stem. When the butterfly valve is in a closed state, the valve plate 2 separates the inner cavity of the valve body 1 into independent water inlet chamber 11 and water outlet chamber 12 in the axial direction.

[0038] A sealing structure 1 is provided between the outer edge of the valve plate 2 and the inner wall of the valve body 1. The sealing structure 1 includes a sealing ring 101, which is embedded in the inner wall of the valve body 1. The sealing ring 101 is a hollow structure, and the inner cavity of the sealing ring 101 is connected to the water inlet cavity 11 through a water inlet pipe 102 with a control valve 1. After the sealing ring 101 expands, it is in close contact with the outer edge of the valve plate 2, thereby achieving sealing between the valve plate 2 and the valve body 1.

[0039] There is also a sealing structure 2 between the outer edge of the valve plate 2 and the inner wall of the valve plate 2. The sealing structure 2 includes a limit stopper 201 and a sealing ring 202. The limit stopper 201 includes two semi-ring pieces fixed on the inner wall of the valve body 1. The two semi-ring pieces are symmetrical with the valve stem as the center and staggered along the axial direction. The axial distance between the two semi-ring pieces is the thickness of the valve plate 2. The positions of the two semi-ring pieces are determined according to the rotation direction of the valve plate 2. The valve plate 2 will not be restricted from rotating 90° to open. The two semi-ring pieces can be used to limit the rotation of the valve plate 2 after closing. The sealing ring 202 is embedded in the side of the limit stopper 201 facing the valve plate 2. The sealing ring 202 is also a hollow structure. The sealing ring 202 is connected to the sealing ring 101 through a pressure equalizing pipe 203 with a control valve 2.

[0040] The butterfly valve has two seals, sealing structure 1 and sealing structure 2. Sealing structure 1 is the main seal, and sealing structure 2 is the transition seal before the valve plate 2 is closed and rotated to the right position. The sealing ability increases with the increase of the medium pressure in the valve body 1, and the sealing is more reliable, without the need to use other pressurizing equipment.

[0041] When the butterfly valve is in the closed state, the control valve 2 is closed, the sealing ring 202 does not expand, and the control valve 1 is opened, and the high-pressure medium in the water inlet chamber 11 enters the sealing ring 101 through the water inlet pipe 102, and the sealing ring 101 expands and squeezes the valve plate 2, thereby achieving sealing between the sealing ring 101 and the outer edge of the valve plate 2;

[0042] When the butterfly valve needs to be opened, the control valve 1 is closed, the control valve 2 is opened, and the valve plate 2 is driven by the power unit 31 to rotate 90 degrees counterclockwise to open. The medium in the sealing ring 101 flows into the sealing ring 202 through the pressure equalizing pipe 203, the sealing ring 202 expands, and the sealing ring 101 contracts after the pressure is released, so that when the power unit 31 drives the valve plate 2 to rotate, the friction between the valve plate 2 and the sealing ring 101 is small, thereby avoiding the use of a high-power driving device;

[0043] When the butterfly valve needs to be closed, the control valve 1 remains closed and the control valve 2 remains open. When the valve plate 2 rotates clockwise and is about to be in place, it will squeeze the expanded sealing ring 202, and the medium in the sealing ring 202 returns to the sealing ring 101 again. In this process, the sealing of the butterfly valve is achieved through the valve plate 2 and the sealing ring 202. The setting of the sealing ring 202 avoids the delay of the butterfly valve closing and the outflow of the medium due to the slow sealing response speed between the valve plate 2 and the sealing ring 101.

[0044] When the valve plate 2 is rotated 90° and closed in place, the control valve 2 is closed and the control valve 1 is opened. At this time, the medium in the sealing ring 202 is completely returned to the sealing ring 101, and the liquid in the water inlet chamber enters the sealing ring 101 through the water inlet pipe 102 to maintain the pressure in the sealing ring 101. At this time, the sealing of the butterfly valve is achieved through the valve plate 2 and the sealing ring 101, and the sealing between the sealing ring 202 and the valve plate 2 fails after shrinkage, and the valve plate 2 will not be squeezed, thereby ensuring the stability of the closed state after the valve plate 2 is rotated into place.

[0045] According to a specific embodiment of the disclosed self-sealing butterfly valve, the centers of the two ends of the sealing ring 101 are eccentrically arranged, the valve plate 2 has a contact surface matching the sealing ring, and the two end surfaces of the valve plate 2 are also non-concentrically arranged, so that a wedge-shaped extrusion seal is formed between the valve plate 2 and the sealing ring 101, and when the valve plate 2 is rotated to open, the wedge-shaped surface between the valve plate 2 and the sealing ring 101 is misaligned, so that the valve plate 2 can squeeze the sealing ring 101.

[0046] This structure is conducive to squeezing the medium in the sealing ring 101 into the sealing ring 202, so that the sealing ring 202 expands to achieve transitional sealing; in addition, the sealing surface of the sealing structure 1 is not concentric with the medium flow direction, which is more conducive to sealing.

[0047] According to a specific embodiment of the disclosed self-sealing butterfly valve, a sealing coating is coated on the sealing surface of the valve plate 2 in contact with the sealing ring 101. The sealing coating is a spray-welded stainless steel coating or a ceramic coating. The sealing coating was originally coated on the valve body 1, but is instead provided on the valve plate 2. Spraying is more convenient, which reduces the torque of the entire valve and makes the operation easier.

[0048] According to a specific embodiment of the disclosed self-sealing butterfly valve, the inner cavity of the sealing ring 101 is also connected to the water outlet cavity 12 through the water outlet pipe 301 with the control valve 3, and the water inlet pipe 102 is provided with a pressure gauge 302. The setting of the pressure gauge 302 is convenient for observing the pressure of the medium in the valve body 1, and the control valve 3 is in a normally closed state. Only when the fluid pressure detected by the pressure gauge 302 exceeds the allowable value, the control valve 3 will be opened to relieve the pressure of the sealing structure to avoid damage to the sealing ring.

[0049] According to a specific embodiment of the disclosed self-sealing butterfly valve, in order to facilitate the use and operation of the butterfly valve, a controller is also included, and the controller is a programmable logic controller based on PLC. The signal input end of the controller is connected to the power unit 31, and the control output end of the controller is connected to the control valve 1 and the control valve 2.

[0050] When the power unit 31 drives the valve plate 2 to rotate counterclockwise to open, the controller receives the signal and controls the control valve 1 to close and the control valve 2 to open; when the power unit 31 drives the valve plate 2 to rotate 90° clockwise to close, the controller receives the signal and controls the control valve 1 to open and the control valve 2 to close. The butterfly valve is operated automatically to avoid manual errors.

[0051] According to a specific embodiment of the disclosed self-sealing butterfly valve, the valve stem includes an upper shaft 41 and a lower shaft 42, the lower end of the upper shaft 41 is inserted into the vertical center hole of the valve plate 2, and is fixed by a transverse pin, the upper end of the upper shaft 41 extends out of the valve body 1 and a rotary seal is provided between the valve body 1. The upper end of the lower shaft 42 is inserted into the vertical center hole of the valve plate 2, and is fixed by a transverse pin, and the lower end of the lower shaft 42 is rotatably connected to the valve body 1.

[0052] According to a specific embodiment of the disclosed self-sealing butterfly valve, the rotary seal includes a sealing packing 43, which is spirally wound on the upper shaft 41 to achieve multi-pass sealing. A boss is provided on the valve body 1 for positioning the sealing packing 43 downward, and a packing gland 44 is provided above the sealing packing 43 to achieve positioning of the sealing packing 43.

[0053] The above are only preferred embodiments of the present invention. Any simple modification, deformation and equivalent substitution made by anyone to the present invention based on the contents of the present invention shall fall within the protection scope of the present invention.

Claims

1. A self-sealing butterfly valve, comprising a valve body (1), a valve stem and a valve plate (2), wherein the valve stem is rotatably fixed to the valve body (1), one end of which is connected to a power unit (31) for driving the valve stem to rotate, the valve plate (2) is located in the valve body (1) and is fixed to the valve stem, and when the butterfly valve is in a closed state, the valve plate (2) divides the inner cavity of the valve body (1) into independent water inlet chambers (11) and water outlet chambers (12) in the axial direction, characterized in that: A sealing structure 1 is provided between the outer edge of the valve plate (2) and the inner wall of the valve body (1), and the sealing structure 1 comprises: A sealing ring (101) is embedded in the inner wall of the valve body (1); the sealing ring (101) is a hollow structure; the inner cavity of the sealing ring (101) is connected to the water inlet cavity (11) via a water inlet pipe (102) with a control valve (1); after the sealing ring (101) expands, it is in close contact with the outer edge of the valve plate (2); a sealing coating is coated on the sealing surface of the valve plate (2) in contact with the sealing ring (101); the inner cavity of the sealing ring (101) is also connected to the water outlet cavity (12) via a water outlet pipe (301) with a control valve (3); and a pressure gauge (302) is provided on the water inlet pipe (102); A second sealing structure is provided between the outer edge of the valve plate (2) and the inner wall of the valve plate (2), and the second sealing structure comprises: A limit stopper (201), the limit stopper (201) comprising two semi-ring plates fixed on the inner wall of the valve body (1), the two semi-ring plates being symmetrical with the valve stem as the center and staggered in the axial direction, and being used for limiting the rotation of the valve plate (2) after closing; and The second sealing ring (202) is embedded in the side of the limit stopper (201) facing the valve plate (2). The second sealing ring (202) is also a hollow structure. The second sealing ring (202) is connected to the first sealing ring (101) through a pressure equalizing pipe (203) with a control valve 2.

2. The self-sealing butterfly valve according to claim 1, characterized in that: The centers of the two ends of the sealing ring (101) are eccentrically arranged, and the valve plate (2) has a contact surface that matches the sealing ring, so that a wedge-shaped extrusion seal is formed between the valve plate (2) and the sealing ring (101), and when the valve plate (2) is rotated to open, the wedge-shaped surface between the valve plate (2) and the sealing ring (101) is misaligned, so that the valve plate (2) can squeeze the sealing ring (101).

3. The self-sealing butterfly valve according to claim 1, characterized in that: Also includes: The controller has a signal input end connected to the power unit (31), and a control output end connected to the first control valve and the second control valve.

4. The self-sealing butterfly valve according to claim 1, characterized in that: The valve stem comprises: The upper shaft (41) has a lower end inserted into the vertical center hole of the valve plate (2) and fixed by a transverse pin, and an upper end extending out of the valve body (1) and a rotary seal is provided between the upper end and the valve body (1); and The upper end of the lower shaft (42) is inserted into the vertical center hole of the valve plate (2) and is fixed by a transverse pin, and the lower end of the lower shaft is rotatably connected to the valve body (1).

5. The self-sealing butterfly valve according to claim 4, characterized in that: The rotary seal comprises: The sealing packing (43) is spirally wound on the upper shaft (41), a boss for positioning the sealing packing (43) downward is provided on the valve body (1), and a packing gland (44) is provided above the sealing packing (43).

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