A flue fireproof backflow preventer valve

Abstract

This utility model relates to a flue fireproof backflow preventer, comprising a valve body, a valve plate, and a hinge mechanism, as well as a valve plate locking mechanism. The valve plate locking mechanism includes a hinge seat, a locking element, a fusible link, and a limiting element. The hinge seat is mounted on the valve body. One end of the locking element is hinged to the hinge seat via a locking torsion spring. The locking element has a through hole, through which the free end of the fusible link passes and connects to the limiting element. The fusible link includes a first fusible link and a second fusible link. The limiting element is mounted on the first fusible link, and the second fusible link is connected to the hinge seat. The valve body has a positioning hole for the hinge seat or the second fusible link to extend. This utility model has a simple structure and is easy to operate. It can meet the requirements of normal kitchen ventilation and exhaust of smoke to the public flue, prevent the backflow of high-temperature smoke in the public flue, and prevent high-temperature smoke from entering the public flue during a kitchen fire. It can effectively prevent the spread of fire, giving this flue fireproof backflow preventer high fire resistance and wider application.

Description

Technical Field

[0001] This utility model relates to a flue fireproof backflow preventer valve, belonging to the technical field of flue check valves. Background Technology

[0002] Modern urban architecture is dominated by high-rise or mid-rise buildings. Two major factors affecting indoor air quality in residential buildings are: odor transfer from kitchen ducts and exhaust gas pollution from bathrooms, with the backflow from shared ducts being particularly significant. A shared duct refers to a vertical exhaust duct in a residential building used to exhaust kitchen fumes and cooking fumes. Residents use exhaust fans and range hoods installed by themselves to collect and centrally expel the fumes from kitchens on each floor.

[0003] Kitchen exhaust ducts are connected to the building's common exhaust duct. To prevent fumes from the common exhaust duct from flowing back into the kitchen, fire-resistant backflow preventers need to be installed in both the common exhaust duct and the individual kitchen exhaust ducts. This places higher demands on these fire-resistant backflow preventers, requiring a system that not only provides ventilation and discharges fumes into the common exhaust duct but also prevents fumes from entering the kitchen. More importantly, in the event of a fire, it should prevent the fire from spreading to the kitchen through the common exhaust duct. Furthermore, in the event of a fire in the kitchen, the backflow preventer should close promptly to prevent fire from entering the common exhaust duct and affecting other residents. Summary of the Invention

[0004] This utility model addresses the shortcomings of existing technologies by providing a flue fireproof backflow preventer valve.

[0005] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A flue fireproof backflow preventer valve includes a valve body, a valve plate and a hinge mechanism. The valve body is provided with an exhaust channel and an exhaust port. The valve plate is connected to the valve body through the hinge mechanism. Under the action of the hinge mechanism, the valve plate can open or close the exhaust port.

[0006] It also includes a valve plate locking mechanism, which is used to lock the valve plate to close the exhaust port in the event of a fire. The valve plate locking mechanism includes a hinge seat, a locking element, a fusible link, and a limiting element. The hinge seat is disposed on the valve body. One end of the locking element is hinged to the hinge seat through a locking torsion spring. The locking element has a through hole. The fusible link is disposed on the hinge seat. The free end of the fusible link passes through the through hole and is connected to the limiting element.

[0007] The fusible link includes a first fusible link and a second fusible link connected to the first fusible link. The limiting member is disposed on the first fusible link. The second fusible link is connected to the hinge seat. The valve body is provided with a positioning hole for the second fusible link to extend out.

[0008] Alternatively, the fusible link includes a first fusible link and a second fusible link connected to the first fusible link, the hinge seat is made of metal, the limiting member is disposed on the first fusible link, the second fusible link is welded to the hinge seat, and the valve body is provided with a positioning hole for the hinge seat to extend out.

[0009] The beneficial effects of this utility model are as follows: The valve plate is connected to the valve body through a hinge mechanism. Under the action of the hinge mechanism, the valve plate can open to meet the daily exhaust gas requirements and can also close to prevent backflow of flue gas in the public flue. When the temperature in the public flue rises to the melting point of the fusible link, the first fusible link will melt, and the limiting member will no longer limit the locking member. Under the action of the locking torsion spring, the locking member can rotate to the locking position on the valve plate, thereby locking the valve plate and closing the exhaust port, effectively preventing the fire in the public flue from spreading to the kitchen area. When a fire occurs in the kitchen, the hinge seat can stably transmit the heat to the second fusible link, or the extended second fusible link will melt at high temperature. After the fusible link melts, the limiting member cannot limit the locking member. Under the action of the locking torsion spring, the locking member rotates and acts on the valve plate, locking the valve plate and closing the exhaust port, preventing high-temperature flue gas from entering the public flue and preventing the fire from spreading. This utility model has a simple structure and is easy to operate. It can meet the requirements of normal ventilation and exhaust of kitchen smoke to the public flue, prevent the backflow of high-temperature smoke in the public flue, and prevent high-temperature smoke from entering the public flue during a kitchen fire. It can effectively prevent the spread of fire, making the flue fireproof backflow valve have high fire resistance and wider application.

[0010] Based on the above technical solution, the present invention can be further improved as follows.

[0011] Furthermore, the hinge mechanism includes a hinge shaft, a hinge torsion spring mounted on the hinge shaft, and a connecting plate. The hinge shaft is disposed on the valve body or hinge seat. One end of the connecting plate is rotatably connected to the hinge shaft, and the other end is connected to the valve plate. One end of the hinge torsion spring acts on the valve body, and the other end acts on the connecting plate.

[0012] The beneficial effect of adopting the above-mentioned further solution is that, when in use, under the action of the exhaust fan or range hood, the kitchen fumes can enter the common flue through the open valve port between the valve plate and the valve body. When not in use, the valve plate is closed under the action of the hinge torsion spring. The cooperation between the valve plate and the valve body can prevent the fumes in the common flue from entering the kitchen. Under the action of the hinge mechanism, the valve plate can switch between the open and closed states to ensure smooth ventilation.

[0013] Furthermore, the connecting plate is provided with two connecting lugs, and the connecting lugs are provided with connecting shaft holes for the hinge shaft to pass through; the hinge seat is provided with two hinge lugs, and the hinge lugs are provided with hinge shaft holes for positioning the hinge shaft.

[0014] The beneficial effects of adopting the above-mentioned further solution are that the connecting lugs enable the connecting plate to rotate with the hinge shaft, laying a solid foundation for the smooth rotation of the valve plate when opening and closing, and reducing friction and noise. The two hinge lugs and the corresponding hinge shaft holes can more securely position the hinge shaft, which is mounted on the hinge seat, facilitating subsequent maintenance and replacement.

[0015] Furthermore, a sealing ring is provided between the valve plate and the valve body, and the sealing ring can be provided on the valve plate or the valve body.

[0016] The beneficial effect of adopting the above-mentioned further solution is that the sealing ring can improve the sealing performance of the valve plate when the valve plate closes the exhaust port, thus preventing flue gas leakage.

[0017] Furthermore, a magnet is provided between the valve plate and the valve body. The magnet is disposed on the valve body or the valve plate, and the valve plate or the valve body is made of a metal material that can be attracted to the magnet.

[0018] The beneficial effect of adopting the above-mentioned further solution is that the setting of the magnet makes the fit between the valve plate and the valve body tighter, avoiding the valve plate from being opened by the pressure difference on both sides when the exhaust fan or range hood is not working, and avoiding backflow of smoke caused by the opening of the valve plate when not working; while when the exhaust fan or range hood is working, the magnet will not interfere with the opening of the valve plate and the smoke can be discharged normally.

[0019] Furthermore, the connecting plate is provided with a plate groove for positioning the hinge torsion spring.

[0020] The beneficial effect of adopting the above-mentioned further solution is that the end of the hinged torsion spring can act at the plate groove position, the plate groove setting will not affect the connection between the connecting plate and the valve plate, and the connection between the connecting plate and the valve plate is stable and reliable.

[0021] Furthermore, the other end of the locking member is provided with a locking protrusion that acts on the surface of the valve plate.

[0022] The beneficial effects of adopting the above-mentioned further solution are that the locking protrusion can directly contact the valve plate, making the locking element lock the valve plate more securely. In addition, the area of ​​the locking protrusion acting on the valve plate is small. After the fusible link melts at high temperature, it can quickly reach the locking position under the action of the locking torsion spring to form an effective locking structure. This ensures the stable operation of the valve plate locking mechanism in emergency situations such as fires, and effectively prevents smoke backflow and fire spread.

[0023] Furthermore, the valve body includes a valve mounting seat and an exhaust pipe disposed on the valve mounting seat, the exhaust pipe being used to connect with an oil fume duct.

[0024] The beneficial effect of adopting the above-mentioned further solution is that the valve mounting seat is fixedly installed at the flue opening, realizing the installation and positioning of the flue fireproof backflow preventer valve, ensuring that the backflow of smoke in the public flue can be effectively prevented when the valve plate is closed, and having a fireproof function, ensuring that it can play a backflow preventer role in extreme situations such as fire, and protecting family safety.

[0025] Furthermore, the valve mounting base is also provided with engaging torsion springs on both sides for engaging with the flue opening.

[0026] The advantage of adopting the above-mentioned further solution is that one end of the engaging torsion spring is fixed to the valve mounting seat, while the other end is elastically engaged with the inner wall of the flue opening, ensuring stable positioning between the valve mounting seat and the flue opening. This engaging torsion spring facilitates installation and disassembly, making it more convenient and faster for users to maintain or replace the check valve.

[0027] Furthermore, the exhaust duct is a straight pipe structure or a stepped pipe structure, and the stepped pipe structure includes a small-diameter pipe section and a large-diameter pipe section.

[0028] The beneficial effect of adopting the above-mentioned further solution is that the exhaust pipe used to connect with the fume duct can have a single outer diameter, such as a straight pipe structure, or it can have a multi-outer diameter structure. The stepped pipe structure allows the exhaust pipe to better adapt to fume ducts of different sizes when connected to the fume duct, thus improving the flexibility of the connection.

[0029] Furthermore, the valve plate is inclinedly disposed within the valve body.

[0030] The beneficial effect of adopting the above-mentioned further solution is that, during installation, the exhaust port of the flue fireproof check valve can be positioned at the upper part of the valve or at the lower part of the valve. If the opening is at the upper part of the valve, the upper part of the valve plate can be tilted towards the common flue, so that the valve plate can better guide the oil fumes to be discharged smoothly when it is opened, reducing the retention of oil fumes in the valve body, thereby improving the smoke exhaust efficiency. The tilted valve plate can also prevent the rising smoke flow or flame backflow in the common flue, thus enhancing the fireproof performance. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0032] Figure 2 for Figure 1 Front view structural diagram;

[0033] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure along the AA direction;

[0034] Figure 4 for Figure 2 A three-dimensional structural diagram of its cross-section;

[0035] Figure 5 This is a three-dimensional structural diagram of Embodiment 1 of the present invention;

[0036] Figure 6 This is a schematic diagram of the structure of Embodiment 2 of this utility model;

[0037] Figure 7 for Figure 6 A three-dimensional structural diagram of its cross-section;

[0038] Figure 8 This is a three-dimensional structural diagram of Embodiment 2 of the present invention;

[0039] In the diagram, 1 is the valve body; 101 is the valve mounting seat; 102 is the exhaust pipe; 2 is the valve plate; 3 is the hinge seat; 4 is the locking element; 401 is the locking protrusion; 5 is the first fusible link; 6 is the second fusible link; 7 is the limiting element; 8 is the locking torsion spring; 9 is the hinge shaft; 10 is the hinge torsion spring; 11 is the connecting plate; 12 is the engaging torsion spring; and 13 is the positioning hole. Detailed Implementation

[0040] The principles and features of this utility model are described below with reference to examples. The examples are only used to explain this utility model and are not intended to limit the scope of this utility model.

[0041] Example 1, as Figures 1-5 As shown, a flue fireproof backflow preventer includes a valve body 1, a valve plate 2, and a hinge mechanism. The valve body 1 is provided with an exhaust channel and an exhaust port. The valve plate 2 is connected to the valve body 1 through the hinge mechanism. Under the action of the hinge mechanism, the valve plate 2 can open or close the exhaust port.

[0042] It also includes a valve plate locking mechanism, which is used to lock the valve plate 2 to close the exhaust port in the event of a fire. The valve plate locking mechanism includes a hinge seat 3, a locking element 4, a fusible link, and a limiting element 7. The hinge seat 3 is disposed on the valve body 1. One end of the locking element 4 is hinged to the hinge seat 3 through a locking torsion spring 8. The locking element 4 is provided with a through hole. The fusible link is disposed on the hinge seat 3. The free end of the fusible link passes through the through hole and is connected to the limiting element 7. The limiting element 7 can not only limit the locking element 4, but also limit the opening and closing of the valve plate 2 when the valve plate 2 is open.

[0043] The fusible link includes a first fusible link 5 and a second fusible link 6 connected to the first fusible link 5. The hinge seat 3 is made of metal. The limiting member 7 is disposed on the first fusible link 5. The second fusible link 6 is welded to the hinge seat 3. The valve body 1 is provided with a positioning hole 13 for the hinge seat 3 to extend out. The hinge seat 3 can extend outward from the valve body 1 through the positioning hole 13. In the event of a fire in the kitchen, as the temperature rises, the extended metal hinge seat 3 will also heat up, transferring the temperature to the second fusible link 6 installed on its surface. The second fusible link 6 will melt, and the limiting member 7 will be unable to limit the locking member 4. The locking member 4 will be unrestrained and will automatically rotate under the action of the locking torsion spring 8, thereby locking the valve plate 2 and closing the exhaust vent, effectively preventing the fire from spreading. When high-temperature smoke appears in the public flue due to a fire, the first fusible link 5 will also melt. Similarly, the limiting member 7 will be unable to limit the locking member 4, and the locking member 4 will rotate to the locked position under the action of the locking torsion spring 8, locking the valve plate 2 and closing the exhaust vent to prevent the high-temperature smoke from the public flue from entering the kitchen.

[0044] The first fuse element 5 and the second fuse element 6 have an L-shaped structure.

[0045] The hinge mechanism includes a hinge shaft 9, a hinge torsion spring 10 mounted on the hinge shaft 9, and a connecting plate 11. The hinge shaft 9 is mounted on the valve body 1 or the hinge seat 3. One end of the connecting plate 11 is rotatably connected to the hinge shaft 9, and the other end is connected to the valve plate 2. One end of the hinge torsion spring 10 acts on the valve body 1, and the other end acts on the connecting plate 11. In use, under the action of an exhaust fan or range hood, kitchen fumes can enter the common flue through the open valve port between the valve plate 2 and the valve body 1. When not in use, the valve plate 2 is closed under the action of the hinge torsion spring 10. The cooperation between the valve plate 2 and the valve body 1 can prevent fumes in the common flue from entering the kitchen. Under the action of the hinge mechanism, the valve plate 2 can switch between open and closed states to ensure smooth ventilation.

[0046] The connecting plate 11 is provided with two connecting lugs, and the connecting lugs are provided with connecting shaft holes for the hinge shaft 9 to pass through. The connecting lugs enable the connecting plate 11 to be rotatably connected to the hinge shaft 9, laying a good foundation for the smooth rotation of the valve plate 2 when opening and closing, and reducing friction and noise.

[0047] The hinge base 3 is provided with two hinge lugs, and each hinge lug has a hinge shaft hole for positioning the hinge shaft 9. The two hinge lugs and the corresponding hinge shaft holes can more securely position the hinge shaft 9, which is mounted on the hinge base 3, facilitating subsequent maintenance and replacement.

[0048] A sealing ring is also provided between the valve plate 2 and the valve body 1. The sealing ring can be disposed on the valve plate 2 or the valve body 1. The sealing ring can improve the sealing performance of the valve plate when the exhaust port is closed, thus preventing flue gas leakage.

[0049] A magnet is also provided between the valve plate 2 and the valve body 1. The magnet is disposed on the valve body 1 or the valve plate 2, and the valve plate 2 or the valve body 1 is made of a metal material that can be magnetically attracted to the magnet. The magnet makes the fit between the valve plate and the valve body tighter, preventing the valve plate from being accidentally opened due to pressure difference when the exhaust fan or range hood is not working, and preventing backflow of smoke caused by the valve plate opening when not working; while when the exhaust fan or range hood is working, the magnet will not interfere with the opening of the valve plate, allowing for normal smoke discharge.

[0050] The connecting plate 11 is provided with a groove for positioning the hinge torsion spring 10. The end of the hinge torsion spring 10 can act at the position of the groove. The setting of the groove will not affect the connection between the connecting plate 11 and the valve plate 2, and the connection between the connecting plate 11 and the valve plate 2 is stable and reliable.

[0051] The other end of the locking member 4 is provided with a locking protrusion 401 that acts on the surface of the valve plate 2. The locking protrusion 401 can directly contact the valve plate 2, so that the locking member 4 can lock the valve plate 2 more securely. In addition, the area of ​​the locking protrusion 401 acting on the valve plate 2 is small. After the fusible link melts at high temperature, it can quickly reach the locking position under the action of the locking torsion spring 8 to form an effective locking structure. This ensures the stable operation of the valve plate locking mechanism in emergency situations such as fire, and effectively prevents smoke backflow and fire spread.

[0052] The valve body 1 includes a valve mounting base 101 and an exhaust pipe 102 disposed on the valve mounting base 101. The exhaust pipe 102 is used to communicate with the fume extraction duct. The valve plate locking mechanism is disposed inside the exhaust pipe. The valve mounting base 101 is fixedly installed at the flue opening to realize the installation and positioning of the flue fireproof backflow preventer valve, ensuring that when the valve plate 2 is closed, it can effectively prevent the backflow of smoke in the public flue, and has a fireproof function, ensuring that it can play a backflow preventer role in extreme situations such as fire, and protect the safety of the family.

[0053] The valve mounting base 101 is also provided with engaging torsion springs 12 on both sides for engaging with the flue opening. One end of the engaging torsion spring 12 is fixed to the valve mounting base 101, and the other end is elastically engaged with the inner wall of the flue opening to ensure stable positioning between the valve mounting base 101 and the flue opening. The engaging torsion spring 12 is easy to install and remove, making it more convenient and quick for users to maintain or replace the check valve.

[0054] The exhaust duct 102 has a stepped pipe structure, which includes a small-diameter pipe section and a large-diameter pipe section. The exhaust duct 102 is used to connect with the fume extraction duct and can have a multi-outer diameter structure. The valve locking mechanism can be set on the small-diameter pipe section. The stepped pipe structure allows the exhaust duct 102 to better adapt to fume extraction ducts of different sizes when connected to the fume extraction duct, improving the flexibility of the connection.

[0055] The valve plate 2 is inclinedly disposed within the valve body 1. During installation, the exhaust port of this flue fireproof check valve can be positioned either at the top of the valve or at the bottom. If the opening is at the top, the upper part of the valve plate 2 can be inclined towards the common flue, allowing the valve plate 2 to better guide the fumes out smoothly when open, reducing fumes buildup within the valve body and improving exhaust efficiency. The inclined valve plate 2 also prevents backflow of rising smoke or flames from the common flue, enhancing fire resistance.

[0056] Example 2, as Figures 6-8 As shown, the exhaust pipe 102 is a straight pipe structure. The exhaust pipe 102 is used to connect with the fume extraction duct and can be a straight pipe structure with a certain outer diameter. The rest of the structure is the same as in Embodiment 1, so it will not be described again here.

[0057] In embodiment 3, the fusible link includes a first fusible link 5 and a second fusible link 6 connected to the first fusible link 5. The limiting member 7 is disposed on the first fusible link 5, and the second fusible link 6 is connected to the hinge seat 3. The valve body 1 is provided with a positioning hole 13 for the second fusible link 6 to extend out. The first fusible link 5 can sense the temperature of the flue gas in the public flue, and the second fusible link 6 extending out of the positioning hole 13 can sense the temperature of the flue gas in the kitchen. Whether there is a fire in one's own kitchen in the building or in other residents' homes, the second fusible link 6 and the first fusible link 5 can melt in time, so that the limiting member 7 no longer limits the locking member 4. The locking member 4 can automatically rotate to the locking position acting on the valve plate 2 under the action of the locking torsion spring 8, locking the valve plate 2 to achieve the purpose of closing the exhaust port of the valve plate 2, preventing high temperature flue gas from entering the public flue or the high temperature flue gas from the public flue from entering the kitchen when the kitchen is on fire. It can achieve the purpose of isolating high temperature flue gas both indoors and outdoors. The remaining structure is the same as in Example 1 or Example 2, so it will not be described again here.

[0058] The valve plate 2 of this utility model is connected to the valve body 1 through a hinge mechanism. Under the action of the hinge mechanism, the valve plate 2 can open to meet the daily exhaust needs of flue gas, and can also close to prevent backflow of flue gas in the public flue. When the temperature in the public flue rises to the melting point of the fusible link, the fusible link will melt, and the limiting member 7 will no longer limit the locking member 4. Under the action of the locking torsion spring 8, the locking member 4 can rotate to the locking position on the valve plate 2, thereby locking the valve plate 2 and closing the exhaust port, effectively preventing the fire in the public flue from spreading to the kitchen area. In the event of a fire in the kitchen, the fusible link can also melt, so that the limiting member 7 will no longer limit the locking member 4. Under the action of the locking torsion spring 8, the locking member 4 can automatically rotate to the locking position on the valve plate 2, locking the valve plate 2, thereby closing the exhaust port and preventing high-temperature flue gas from entering the public flue when the kitchen is on fire. It can achieve the purpose of isolating high-temperature flue gas both indoors and outdoors.

[0059] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A flue fireproof backflow preventer valve, characterized in that, It includes a valve body (1), a valve plate (2) and a hinge mechanism. The valve body (1) is provided with an exhaust channel and an exhaust port. The valve plate (2) is connected to the valve body (1) through the hinge mechanism. Under the action of the hinge mechanism, the valve plate (2) can open or close the exhaust port. It also includes a valve plate locking mechanism, which is used to lock the valve plate (2) to close the exhaust port in the event of a fire; the valve plate locking mechanism includes a hinge seat (3), a locking member (4), a fusible link and a limiting member (7), the hinge seat (3) is disposed on the valve body (1), one end of the locking member (4) is hinged to the hinge seat (3) through a locking torsion spring (8), the locking member (4) is provided with a through hole, and the free end of the fusible link passes through the through hole and is connected to the limiting member (7); The fusible link includes a first fusible link (5) and a second fusible link (6) connected to the first fusible link (5). The limiting member (7) is disposed on the first fusible link (5). The second fusible link (6) is connected to the hinge seat (3). The valve body (1) is provided with a positioning hole (13) for the second fusible link (6) to extend out. Alternatively, the fuse includes a first fuse (5) and a second fuse (6) connected to the first fuse (5), the hinge seat (3) is made of metal, the limiting member (7) is disposed on the first fuse (5), the second fuse (6) is connected to the hinge seat (3), and the valve body (1) is provided with a positioning hole (13) for the locking member (4) to extend out.

2. The flue fireproof check valve according to claim 1, characterized in that, The hinge mechanism includes a hinge shaft (9), a hinge torsion spring (10) fitted on the hinge shaft (9), and a connecting plate (11). The hinge shaft (9) is mounted on the valve body (1) or the hinge seat (3). One end of the connecting plate (11) is rotatably connected to the hinge shaft (9), and the other end is connected to the valve plate (2). One end of the hinge torsion spring (10) acts on the valve body (1), and the other end acts on the connecting plate (11).

3. The flue fireproof check valve according to claim 2, characterized in that, The connecting plate (11) is provided with two connecting ear plates, and the connecting ear plates are provided with connecting shaft holes for the hinge shaft (9) to pass through; the hinge seat (3) is provided with two hinge ear plates, and the hinge ear plates are provided with hinge shaft holes for positioning the hinge shaft (9).

4. The flue fireproof check valve according to claim 1, characterized in that, A sealing ring is also provided between the valve plate (2) and the valve body (1), and the sealing ring can be provided on the valve plate (2) or the valve body (1).

5. The flue fireproof check valve according to claim 1, characterized in that, A magnet is also provided between the valve plate (2) and the valve body (1). The magnet is set on the valve body (1) or the valve plate (2). The valve plate (2) or the valve body (1) is made of a metal material that can be attracted to the magnet.

6. The flue fireproof check valve according to any one of claims 1-5, characterized in that, The other end of the locking member (4) is provided with a locking protrusion (401) that acts on the surface of the valve plate (2).

7. The flue fireproof check valve according to any one of claims 1-5, characterized in that, The valve body (1) includes a valve mounting base (101) and an exhaust pipe (102) disposed on the valve mounting base (101), the exhaust pipe (102) being used to connect with the fume duct.

8. The flue fireproof check valve according to claim 7, characterized in that, The valve mounting base (101) is also provided with engagement torsion springs (12) on both sides for engaging with the flue.

9. The flue fireproof check valve according to claim 7, characterized in that, The exhaust duct (102) is a straight pipe structure or a stepped pipe structure, and the stepped pipe structure includes a small-diameter pipe section and a large-diameter pipe section.

10. The flue fireproof check valve according to any one of claims 1-5, characterized in that, The valve plate (2) is inclinedly disposed inside the valve body (1).

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