Fireproof check valve for smoke exhaust pipeline

Abstract

The utility model discloses a fireproof check valve for a smoke exhaust pipeline, which relates to the technical field of smoke exhaust and ventilation pipelines and comprises a valve pipe and a valve, and the valve is hinged to one end of the valve pipe and forms a normally-closed opening and closing structure which can be opened when being impacted by airflow; a hinge seat is arranged in the valve pipe, and a reset arm set used for being in linkage with the valve to reset is arranged on the hinge seat. The valve pipe and / or the reset arm set are / is provided with a permanent magnet, and the adsorption force of the permanent magnet is configured to enable the valve to be kept in a closed state when the airflow impact force does not reach a threshold value. The utility model mainly solves the problem that the fireproof check valve of the smoke exhaust pipeline is easy to open by mistake; according to the fireproof check valve for the smoke exhaust pipeline, the permanent magnet is arranged at the position of the valve pipe and / or the reset arm set, the adsorption force of the permanent magnet is configured to enable the valve to be kept in the closed state when the impact force of airflow does not reach the threshold value, the valve can be opened by needing certain impact force, and the problem that the valve is opened by mistake is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of smoke exhaust ventilation ducts, in particular to a fire-proof check valve for smoke exhaust ducts. Background Art

[0002] At present, some buildings have check valves installed in kitchen and bathroom exhaust ducts to prevent gas from flowing back into the room. At the same time, some check valves have fire prevention functions.

[0003] The Chinese utility model patent announcement text with announcement number CN210290890U and name "A fire-proof check valve for a smoke exhaust duct" records a typical fire-proof check valve structure for a smoke exhaust duct. When smoke exhaust is required, smoke enters valve tube 1 from the indoor smoke exhaust duct through the inlet of valve tube 1, and the smoke impacts valve 2. After overcoming the elastic force of the reset torsion spring 43, the smoke pushes valve 2 open. At the same time, the reset straight arm 41 is lifted by the reset arc arm 42. At this time, the smoke in the indoor smoke exhaust duct can be discharged into the outdoor smoke exhaust duct. After the smoke is exhausted, valve 2 is no longer subjected to external force, the reset torsion spring 43 is reset and the reset straight arm 41 is pressed down, and the reset straight arm 41 tightens valve 2 through the reset arc arm 42, so that valve 2 is close to the outlet of valve tube 1. At this time, valve 2 returns to a closed state.

[0004] In the above process, the valve 2 will open when it is impacted by a very small force (such as natural wind), which may easily cause the problem of the valve opening by mistake. Utility Model Content

[0005] The utility model aims to provide a fire-proof check valve for a smoke exhaust pipe, the valve of which is not easy to be opened by mistake.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a smoke exhaust duct fire check valve, comprising a valve tube and a valve, wherein the valve is hinged at one end of the valve tube and forms a normally closed opening and closing structure that can be opened when airflow impacts; a hinged seat is provided in the valve tube, and a reset arm group for linking the valve to reset is provided on the hinged seat; a permanent magnet is provided at the valve tube and / or the reset arm group, and the adsorption force of the permanent magnet is configured to enable the valve to remain in a closed state when the airflow impact force does not reach a threshold value.

[0007] In the above technical solution, the reset arm group includes a reset straight arm, a reset arc arm and a reset torsion spring; the reset straight arm is hinged at the lower part of the hinge seat, and the two ends of the reset arc arm are respectively hinged on the reset straight arm and the valve; the two ends of the reset torsion spring respectively press against the bottom of the valve tube and the reset straight arm to press down the reset straight arm; when the permanent magnet is arranged on the valve tube, it can adsorb the reset straight arm; when the permanent magnet is arranged on the reset straight arm, it can adsorb the valve tube; when the permanent magnet is arranged on the valve tube and the reset straight arm at the same time, the valve tube and the reset straight arm can be adsorbed to each other.

[0008] The above technical solution also includes a fireproof arm group for limiting the action of the reset arm group; a long groove is provided at the bottom of the valve tube, and a fuse is covered on the long groove, and one end of the fuse forms a barrier for limiting the action of the fireproof arm group. The fireproof arm group includes a pressure arm, a support arm and a pressure arm torsion spring; one end of the pressure arm is hinged on the upper part of the hinge seat; one end of the support arm is hinged on the pressure arm, and the other end of the support arm is supported on the barrier of the fuse; the two ends of the pressure arm torsion spring respectively abut against the hinge seat and the pressure arm, so as to press down the pressure arm after the fuse is melted and press the reset straight arm through the pressure arm.

[0009] In the above technical solution, a snap-fitting groove cooperating with the top of the pressure arm is provided on the reset straight arm.

[0010] In the above technical solution, the fuse pieces are provided with more than two pieces, and the fuse pieces are stacked; the fuse piece on the bottom layer covers the long groove, and the fuse piece on the top layer forms the retaining wall.

[0011] In the above technical solution, the retaining wall is in a hook shape matching the bottom of the support arm.

[0012] The above technical solution also includes an air guide seat, and the valve tube is inserted into the air guide seat.

[0013] In the above technical solution, an air guide plate is fixed in the air guide seat; and the outlet of the air guide seat forms a convex edge.

[0014] In the above technical solution, a recessed portion is formed at the bottom of the valve tube, and the long groove is opened in the recessed portion.

[0015] In the above technical solution, a limit arm is fixed on the valve, and a hook is formed at the end of the limit arm to hook the outlet of the valve pipe.

[0016] Compared with the prior art, the beneficial effects of the utility model are as follows: the smoke exhaust duct fire check valve of the utility model is provided with a permanent magnet at its valve tube and / or reset arm group, and the adsorption force of the permanent magnet is configured to enable the valve to remain in a closed state when the airflow impact force does not reach a threshold value, so that the valve requires a certain impact force to open, thereby avoiding the problem of incorrect opening of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of the first embodiment of the utility model when the valve is not opened.

[0018] Figure 2 This is a schematic structural diagram of the first embodiment of the utility model when the valve is open.

[0019] Figure 3 This is a schematic diagram of the structure of the first embodiment of the utility model after the fuse piece is blown.

[0020] Figure 4 It is a schematic diagram of the coordination of the recessed portion, the long groove and the fuse piece in the first embodiment of the utility model.

[0021] Figure 5 This is a schematic structural diagram of the second embodiment of the utility model when the valve is not opened.

[0022] Figure 6 This is a schematic diagram of the structure of the second embodiment of the utility model when the valve is open.

[0023] Figure 7 This is a schematic structural diagram of Embodiment 3 of the utility model when the valve is open.

[0024] Figure 8 This is a schematic structural diagram of the fourth embodiment of the utility model when the valve is not opened.

[0025] Fig. 9 for Figure 8 A is a partial enlarged view of the figure.

[0026] Fig.10 This is one of the structural schematic diagrams of the fourth embodiment of the utility model when the valve is not opened.

[0027] Fig.11 This is the second structural schematic diagram of the fourth embodiment of the utility model when the valve is not opened.

[0028] Fig.12 This is the third structural schematic diagram of the fourth embodiment of the utility model when the valve is not opened.

[0029] The accompanying drawings are marked as follows: 1. valve tube; 11. long groove; 12. first sealing edge; 13. recessed portion; 2. valve; 21. second sealing edge; 3. hinged seat; 4. reset arm group; 41. reset straight arm; 411. engaging groove; 42. reset arc arm; 43. reset torsion spring; 5. fireproof arm group; 51. pressure arm; 52. support arm; 53. pressure arm torsion spring; 6. fuse; 61. baffle wall; 7. air guide seat; 71. air guide plate; 72. convex edge; 73. side plate; 8. limit arm; 81. hook; 9. permanent magnet. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] Embodiment 1:

[0032] See also Figure 1-Figure 4 The present embodiment provides a smoke exhaust duct fire check valve, comprising a valve tube 1 and a valve 2; the valve tube 1 is a cylindrical or square metal tube, and its axial cross-section is a right-angle trapezoid. In the present embodiment, the vertical end of the valve tube 1 is an inlet, and the inclined end of the valve tube 1 is an outlet, wherein the outlet of the valve tube 1 is narrowed so that the inner diameter of the outlet of the valve tube 1 is smaller than the inner diameter of the valve tube 1; the valve 2 is a metal circular plate, and the valve 2 is hinged to one end of the valve tube 1 by a hinge; the valve tube 1 and the valve 2 form a normally closed opening and closing structure that can be opened when the airflow impacts.

[0033] A hinged seat 3 is provided in the valve tube 1, and the hinged seat 3 is a metal seat body, which is fixed at the bottom position of the inner wall of the valve tube 1; a reset arm group 4 for linking the valve 2 to reset and a fire-proof arm group 5 for limiting the movement of the reset arm group 4 are provided on the hinged seat 3; a rectangular long groove 11 is opened at the bottom of the valve tube 1, and the long groove 11 is covered with a fuse 6, that is, the fuse 6 is fixed to the inner wall of the valve tube 1 by welding or screwing and covers the long groove 11 from the inside of the valve tube 1, and one end of the fuse 6 forms a retaining wall 61 for limiting the movement of the fire-proof arm group 5.

[0034] Furthermore, a recessed portion 13 is formed at the bottom of the valve tube 1. Specifically, the bottom of the valve tube 1 protrudes toward the outside of the valve tube 11, thereby forming a recessed portion 13 on the inner wall of the valve tube 1, and the long groove 11 is opened in the recessed portion 13; the fuse piece 6 is fixed to the inner wall of the recessed portion 13 of the valve tube 1 and covers the long groove 11 from the inside of the recessed portion 13.

[0035] Specifically, the reset arm group 4 includes a reset straight arm 41, a reset arc arm 42 and a reset torsion spring 43; the reset straight arm 41 is a metal straight arm, one end of which is hinged to the lower part of the hinge seat 3; the reset arc arm 42 is an arc-shaped metal arm, and the two ends of the reset arc arm 42 are respectively hinged to the reset straight arm 41 and the valve 2; the hinge axis of the reset straight arm 41 passes through the main body of the reset torsion spring 43 to fix the reset torsion spring 43, one end of the reset torsion spring 43 is against the inner wall of the bottom of the valve tube 1, and the other end is against the reset straight arm 41 and a hook is formed on the reset straight arm 41, so that the reset torsion spring 43 can press down the reset straight arm 41. The fire-proof arm group 5 includes a pressure arm 51, a support arm 52 and a pressure arm torsion spring 53; the pressure arm 51 is a "U"-shaped metal arm, that is, one end of the pressure arm 51 has an opening and the other end is closed, and the end of the pressure arm 51 with the opening is hinged to the upper part of the hinge seat 3; the support arm 52 is also a "U"-shaped metal arm, that is, one end of the support arm 52 has an opening and the other end is closed, and the end of the support arm 52 with the opening is hinged to the pressure arm 51, and the closed end of the support arm 52 is supported on The retaining wall 61 of the fuse piece 6 is made so that the retaining wall 61 can support the closed end of the support arm 52; the hinge axis of the pressure arm 51 passes through the main body of the pressure arm torsion spring 53 to fix the pressure arm torsion spring 53, one end of the pressure arm torsion spring 53 abuts against the hinge seat 3 and forms a hook on the hinge seat 3, and the other end abuts against the pressure arm 51 and forms a hook on the pressure arm 51, so as to press down the pressure arm 51 after the fuse piece 6 is melted and press the reset straight arm 41 through the pressure arm 51.

[0036] Furthermore, a snap-fitting groove 411 cooperating with the top of the pressing arm 51 is formed on the reset straight arm 41 . In this embodiment, the snap-fitting groove 411 is triangular when viewed from the side of the reset straight arm 41 .

[0037] Furthermore, more than two fuse pieces 6 are provided, and all fuse pieces 6 are stacked in sequence; a fuse piece 6 on the bottom layer covers the long groove 11 , and a fuse piece 6 on the top layer forms a retaining wall 61 .

[0038] In this embodiment, two fuse pieces 6 are provided, a bottom fuse piece 6 is fixed to the inner wall of the recessed portion 13 of the valve tube 1 by welding or screwing and covers the long groove 11 from the inside of the valve tube 1, a top fuse piece 6 is fixed to the surface of the bottom fuse piece 6 by welding, and one end of the top fuse piece 6 forms a retaining wall 61, which is close to the entrance of the valve tube 1.

[0039] Furthermore, the retaining wall 61 of the fuse piece 6 is in a hook shape matching the closed end of the bottom of the support arm 52 .

[0040] When this type of smoke exhaust duct fire check valve is used, it is installed in the smoke exhaust duct, wherein the outdoor smoke exhaust duct is connected to the outlet of the valve pipe 1, the valve 2 is opened in the direction of the outdoor smoke exhaust duct, and the indoor smoke exhaust duct is connected to the inlet of the valve pipe 1.

[0041] See also Figure 1 When the smoke exhaust pipe fire check valve is in normal use, one end of the support arm 52 is supported on the retaining wall 61 of the fuse 6, thereby supporting the pressure arm 51. At this time, the pressure arm torsion spring 53 is in a compressed state; the reset torsion spring 43 presses down the reset straight arm 41, and the reset straight arm 41 tightens the valve 2 through the reset arc arm 42, so that the valve 2 is close to the outlet of the valve pipe 1. At this time, the valve 2 is in a closed state, and the gas in the outdoor smoke exhaust pipe outside the valve 2 cannot enter the valve pipe 1, so as to achieve the purpose of non-return; please refer to Figure 2 When smoke exhaust is required, smoke enters valve tube 1 from the indoor smoke exhaust duct through the inlet of valve tube 1, and smoke impacts valve 2. After overcoming the elastic force of reset torsion spring 43, smoke pushes valve 2 open. At the same time, reset straight arm 41 is lifted by reset arc arm 42. At this time, smoke in the indoor smoke exhaust duct can be discharged into the outdoor smoke exhaust duct. After the smoke is exhausted, valve 2 is no longer subjected to external force, reset torsion spring 43 is reset and reset straight arm 41 is pressed down, and reset straight arm 41 tightens valve 2 through reset arc arm 42, so that valve 2 is close to the outlet of valve tube 1. At this time, valve 2 returns to the closed state.

[0042] See also Figure 3 When a fire occurs, the temperature of the valve tube 1 rises or the flame directly burns the fuse 6, causing the fuse 6 to melt. After losing the support of the retaining wall 61, the support arm 52 cannot support the pressure arm 51, and the pressure arm torsion spring 53 resets and presses the pressure arm 51 down, and the pressure arm 51 is pressed on the reset straight arm 41. The closed part of the pressure arm 51 is embedded in the engaging groove 411 of the reset straight arm 41, so that the pressure arm 51 can tightly press the reset straight arm 41, so that the reset straight arm 41 cannot be lifted, and the valve 2 is forcibly locked. At this time, even if there is airflow impacting the valve 2, the valve 2 cannot be opened because it is tightened by the reset straight arm 41 and the reset arc arm 42, thereby isolating the indoor smoke exhaust duct from the outdoor smoke exhaust duct, preventing the flame from entering the indoor smoke exhaust duct through the valve tube 1, and also preventing the flame from escaping from the outdoor smoke exhaust duct through the valve tube 1, so that the indoor smoke exhaust duct and the outdoor smoke exhaust duct are isolated, achieving the purpose of fire prevention.

[0043] The fireproof check valve for smoke exhaust pipe has a long groove 11 at the bottom of the valve pipe 1, and the long groove 11 is covered with a fusible piece 6. The fusible piece 6 is not easy to fall out of the long groove 11. When there is no fire, the valve 2 is not easy to be forced to lock, so as to achieve a good ventilation effect. At the same time, the fusible piece 6 covers the long groove 11, which increases the fire-exposed area of ​​the fusible piece 6. When a fire occurs, the fusible piece 6 reacts more sensitively, so that the pressure arm 51 can be pressed down in time, thereby locking the valve 2, improving the fireproof and flame-retardant performance of the smoke exhaust pipe, and thus improving residential safety.

[0044] Embodiment 2:

[0045] See also Figure 5-Figure 6 This embodiment provides a smoke exhaust duct fire check valve, which adds an air guide seat 7 based on the smoke exhaust duct fire check valve of the first embodiment.

[0046] The air guide seat 7 is formed by four metal side plates 73 welded together to form a square cylindrical short pipe; the air guide seat 7 is fixed in the outdoor smoke exhaust duct and arranged vertically, that is, the two openings of the air guide seat 7 face upward and downward respectively, among which the openings facing upward are the outlets of the air guide seat 7, and the openings facing downward are the inlets of the air guide seat 7.

[0047] The valve tube 1 is inserted into the air guide seat 7. Specifically, a circular card interface is provided on one of the side panels 73 of the air guide seat 7. The valve tube 1 is inserted through the card interface and is card-connected to the air guide seat 7, so that the outlet of the valve tube 1 is located in the air guide seat 7, and the valve 2 opens toward the inside of the air guide seat 7.

[0048] Furthermore, an air guide plate 71 is fixed in the air guide seat 7; in the present embodiment, the cross section of the air guide plate 71 has two vertical portions and one inclined portion, and the two ends of the inclined portion are respectively engaged with the two vertical portions; the two ends of the air guide plate 71 are respectively welded to two opposite side plates 73, thereby being fixed to the air guide seat 7; when the valve 2 is opened, the airflow from bottom to top is guided by the air guide plate 71, so that the airflow avoids the valve 2 to avoid the valve 2 being mistakenly closed due to the force under the valve 2. At the same time, the airflow from bottom to top is guided by the air guide plate 71, and the direction of the airflow is more unified, thereby increasing the flow rate and allowing the airflow to be discharged through the outdoor smoke exhaust duct as soon as possible.

[0049] Furthermore, the outlet of the air guide seat 7 forms a convex edge 72, that is, the two side panels 73 opposite to each other at the upper opening of the air guide seat 7 extend upward to form a convex edge 72; the convex edge 72 can further guide the airflow from bottom to top, making the direction of the airflow more uniform and further increasing the flow rate.

[0050] Embodiment three:

[0051] See also Figure 7This embodiment provides a smoke exhaust pipe fire check valve, which adds the following technical solutions based on the smoke exhaust pipe fire check valve of embodiment 1:

[0052] A limit arm 8 is fixed on the valve 2, and the limit arm 8 is made of metal. In the present embodiment, the limit arm 8 is in the shape of a plate, one end of the limit arm 8 is welded and fixed on the valve 2, and the other end forms a hook 81, which can hook the inner edge of the outlet of the valve tube 1 to control the opening angle of the valve 2. After the valve 2 is opened, the angle between the valve 2 and the axis of the valve tube 1 is 120°. There are two limit arms 8, and the two limit arms 8 are arranged on both sides of the valve 2.

[0053] By adopting a plate-shaped limiting arm 8, when the valve 2 is opened, the airflow from the indoor smoke exhaust duct cannot be discharged from the side of the valve 2 due to the obstruction of the limiting arm 8, and can only be discharged from the top of the valve 2, so that the direction of the airflow is more uniform, the flow rate is increased, and the airflow can be discharged through the outdoor smoke exhaust duct as soon as possible.

[0054] Of course, in other embodiments, the limiting arm 8 may also be in a strip shape.

[0055] Embodiment 4:

[0056] See also Figure 8 and Fig. 9 This embodiment provides a smoke exhaust pipe fire check valve, which adds the following technical solutions based on the smoke exhaust pipe fire check valve of embodiment 1:

[0057] A first sealing edge 12 is arranged around the outlet of the valve tube 1, and the first sealing edge 12 is integrally formed with the valve tube 1; a second sealing edge 21 is arranged around the edge of the valve 2, and the second sealing edge 21 is integrally formed with the valve 2; after the valve 2 is closed, the second sealing edge 21 surrounds and is tightly attached to the first sealing edge 12.

[0058] The second sealing edge 21 cooperates with the first sealing edge 12 to improve the sealing degree of the fire-proof check valve of the smoke exhaust duct.

[0059] Embodiment five:

[0060] See also Figure 10-12 In this embodiment, in order to solve the problem of erroneous opening of the valve, a permanent magnet 9 is provided at the valve tube 1 and / or the reset arm group 4, and the adsorption force of the permanent magnet 9 is configured to enable the valve 2 to remain in a closed state when the impact force of the airflow does not reach a threshold value.

[0061] In fact, at least the valve tube 1 and the reset arm assembly 4 are made of magnetically attractive materials such as iron or stainless steel.

[0062] Specifically, when the permanent magnet 9 is set on the valve tube 1, it can adsorb the reset straight arm 41; when the permanent magnet 9 is set on the reset straight arm 41, it can adsorb the valve tube 1; when the permanent magnet 9 is set on the valve tube 1 and the reset straight arm 41 at the same time, the valve tube 1 and the reset straight arm 41 can be adsorbed to each other (the opposite poles of the valve tube 1 and the reset straight arm 41 are opposite, so that the valve tube 1 and the reset straight arm 41 are adsorbed to each other).

[0063] It should be noted that the permanent magnet 9 can be fixed by screw locking, adhesive bonding, embedding in metal, and welding on the metal surface; the fixed position of the permanent magnet can be set along the extension direction of the entire reset straight arm 41, and can be slightly offset from the reset straight arm 41.

[0064] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A smoke exhaust pipe fire check valve, comprising a valve pipe and a valve, wherein the valve is hinged at one end of the valve pipe and forms a normally closed opening and closing structure that can be opened when an airflow impacts; A hinged seat is provided in the valve tube, and a reset arm group for linking the valve to reset is provided on the hinged seat; the characteristic is that: A permanent magnet is arranged at the valve tube and / or the reset arm group, and the adsorption force of the permanent magnet is configured to enable the valve to remain in a closed state when the impact force of the airflow does not reach a threshold value.

2. The smoke exhaust pipe fire check valve according to claim 1, characterized in that: The reset arm group includes a reset straight arm, a reset arc arm and a reset torsion spring; The reset straight arm is hinged at the lower part of the hinge seat, and the two ends of the reset arc arm are hinged on the reset straight arm and the valve respectively; The two ends of the reset torsion spring respectively press against the bottom of the valve tube and the reset straight arm to press down the reset straight arm; When the permanent magnet is arranged on the valve tube, it can adsorb the reset straight arm; When the permanent magnet is arranged on the reset straight arm, it can adsorb the valve tube; When the permanent magnet is provided on the valve tube and the reset straight arm at the same time, the valve tube and the reset straight arm can be attracted to each other.

3. The smoke exhaust pipe fire check valve according to claim 2 is characterized in that: Also included is a fire protection arm group for limiting the action of the reset arm group; A long groove is provided at the bottom of the valve tube, and a fuse is covered on the long groove, and one end of the fuse forms a barrier for limiting the action of the fire-proof arm assembly; The fireproof arm group includes a pressure arm, a support arm and a pressure arm torsion spring; One end of the pressure arm is hinged to the upper part of the hinge seat; One end of the support arm is hinged on the pressure arm, and the other end of the support arm is supported on the retaining wall of the fuse piece; The two ends of the pressure arm torsion spring respectively abut against the hinge seat and the pressure arm, so as to press down the pressure arm after the fuse is melted and press the reset straight arm through the pressure arm.

4. The smoke exhaust pipe fire check valve according to claim 3 is characterized in that: The reset straight arm is provided with a snap-fitting groove matched with the top of the pressure arm.

5. The smoke exhaust pipe fire check valve according to claim 3 is characterized in that: The fuse pieces are provided with more than two pieces, and the fuse pieces are stacked; A piece of the fuse piece at the bottom layer covers the long groove, and a piece of the fuse piece at the top layer forms the retaining wall.

6. The smoke exhaust pipe fire check valve according to claim 3, characterized in that: The retaining wall is in a hook shape matching the bottom of the support arm.

7. The smoke exhaust pipe fire check valve according to claim 1, characterized in that: It also includes an air guide seat, and the valve tube is inserted into the air guide seat.

8. The smoke exhaust pipe fire check valve according to claim 7, characterized in that: An air guide plate is fixed in the air guide seat; and a convex edge is formed at the outlet of the air guide seat.

9. The smoke exhaust pipe fire check valve according to claim 3 or 5, characterized in that: A recessed portion is formed at the bottom of the valve tube, and the long groove is arranged in the recessed portion.

10. The smoke exhaust pipe fire check valve according to claim 1, characterized in that: A limiting arm is fixed on the valve, and a hook is formed at the end of the limiting arm to hook the outlet of the valve pipe.

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