A stop check valve

Abstract

The application discloses a stop check valve, which comprises a valve rod part, a valve seat part and a valve core part, the valve rod part is connected with the valve core part in position limitation, the valve rod part comprises a valve rod, the valve core part comprises a valve core, the valve core comprises a first position limiting part, the valve rod comprises a second position limiting part, the first position limiting part is located above the second position limiting part, the projection of the first position limiting part covers at least part of the projection of the second position limiting part along the longitudinal direction of the stop check valve, and the second position limiting part is located in a containing cavity of the valve core. The stop check valve provided by the application is provided with the first position limiting part of the valve core and the second position limiting part of the valve rod, and the first position limiting part and the second position limiting part can abut and limit in position when being disassembled, so that the valve rod and the valve core are connected in position limitation and are regarded as an integral part, thereby facilitating disassembly.

Description

Technical Field

[0001] This application relates to the field of industrial valve technology, and more particularly to a shut-off check valve. Background Technology

[0002] There are many types of industrial valves, one of which is the gate check valve, which combines the functions of a gate valve and a check valve.

[0003] Specifically, the stop check valve includes a valve seat, a valve cover, a valve stem, and a valve core. The valve seat and valve cover are threaded together. The valve core is located within the cavity of the valve seat. The valve cover includes a through hole, through which the valve stem passes, and one end of the valve stem is connected to the valve core for limiting. The valve seat includes a valve port, and the valve core can open or close the valve port. As a moving component, improving the convenience of the valve core during product assembly or maintenance is a problem that needs to be solved by those skilled in the art. Utility Model Content

[0004] To solve the above problems, this utility model provides a shut-off check valve that enables the valve core and valve stem to be disassembled and assembled as a whole.

[0005] This utility model provides a shut-off check valve, comprising: a valve stem component, a valve seat component, and a valve core component. The valve stem component and the valve core component are connected in a limiting manner. The valve stem component includes a valve stem, and the valve core component includes a valve core. The valve core includes a first limiting portion, and the valve stem includes a second limiting portion. The first limiting portion is located above the second limiting portion along the longitudinal direction of the shut-off check valve. The projection of the first limiting portion covers at least a portion of the projection of the second limiting portion. The valve core includes a receiving cavity, and the second limiting portion is located in the receiving cavity.

[0006] The shut-off check valve provided in this application has a valve core including a first limiting part and a valve stem including a second limiting part. During disassembly and assembly, the first limiting part and the second limiting part can abut and limit each other, so that the valve stem and the valve core can be regarded as a whole, which facilitates the disassembly and assembly of the valve core.

[0007] This utility model provides another type of shut-off check valve, including a valve stem component, a valve seat component, and a valve core component. The valve stem component and the valve core component are connected in a limiting manner. The valve stem component includes a valve stem, and the valve core component includes a valve core. The valve core includes a first limiting portion, and the valve stem includes a second limiting portion. The first limiting portion is located above the second limiting portion along the longitudinal direction of the shut-off check valve. The projection of the first limiting portion covers at least a portion of the projection of the second limiting portion. The valve core includes a receiving cavity, and the second limiting portion is located in the receiving cavity. During the disassembly of the shut-off check valve, the first limiting portion can abut against the second limiting portion, and the valve stem can drive the valve core to detach from the valve seat component.

[0008] In the aforementioned shut-off check valve, during the removal process, the first limiting part can abut against the second limiting part, and the valve stem can drive the valve core to detach from the valve seat component, making it easier for the valve core to detach from the valve seat component. Attached Figure Description

[0009] Figure 1 The figure shown is a cross-sectional view of a shut-off check valve in one of its working states according to this utility model.

[0010] Figure 2 As shown Figure 1 A magnified view of a portion of point I;

[0011] Figure 3 As shown Figure 1 A cross-sectional view of the valve core sleeve in the diagram;

[0012] Figure 4 As shown Figure 1 A cross-sectional view of the valve stem and valve core assembly after assembly;

[0013] Figure 5 As shown Figure 4 A magnified view of a portion of section II;

[0014] Figure 6 The diagram shown is a cross-sectional view of the valve stem and valve core assembly after assembly, according to another embodiment.

[0015] Figure 7 As shown Figure 6 A magnified view of a portion of section III;

[0016] Figure 8 As shown Figure 1 Cross-sectional view of the middle valve seat;

[0017] Figure 9 The figure shown is a cross-sectional view of a shut-off check valve under another working state provided by this utility model;

[0018] Figure 10 The image shown is a cross-sectional view of a shut-off check valve under another working condition provided by this utility model.

[0019] Figure label:

[0020] 1-Valve cover assembly, 11-Valve cover;

[0021] 2-Valve stem assembly, 21-Valve stem, 211-Second limiting part, 2112-Second limiting surface, 212-Main body, 213-Third limiting part, 2131-Conical limiting surface, 2132-Lower abutment surface;

[0022] 3-Valve seat assembly; 31-Valve seat body; 310-Valve port; 320-Valve cavity; 330-Fluid inlet; 340-Fluid outlet;

[0023] 4-Valve core component, 41-Valve core, 410-Base portion, 411-Cylindrical portion, 412 / 412A-First limiting portion, 4100-First stepped portion, 4111-Receiving cavity, 4122-First limiting surface;

[0024] 5-Valve core sleeve, 51-Body part, 52-Second step part, 53-Guide section, 54-Receiving section, 55-Receiving cavity, 56-Transition section, 57-Pressure relief hole;

[0025] 6-Spring. Specific Implementation

[0026] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0027] The first embodiment of the shut-off check valve includes: a valve cover component 1, a valve stem component 2, a valve seat component 3, a valve core component 4, and a valve core sleeve 5. The valve cover component 1 and the valve seat component 3 are detachably connected. Specifically, the detachable connection refers to a threaded connection, which can be further reinforced with bolts. Of course, other connection methods can also be used, such as snap-fit ​​connections. The valve stem component 2 and the valve core component 4 are in a limiting connection. The valve cover component 1 includes a valve cover 11, the valve stem component 2 includes a valve stem 21, and the valve core component 4 includes a valve core 41. The valve core 41 includes a first limiting part 412, and the valve stem 21 includes a second limiting part 211. The first limiting part 412 is located above the second limiting part 211. Along the longitudinal direction of the shut-off check valve, the projection of the first limiting part 412 covers at least part of the projection of the second limiting part 211. The valve core 41 includes a receiving cavity 4111, and the second limiting part 211 is located in the receiving cavity 4111. The first limiting part 412 and the second limiting part 211 enable the valve stem 21 and the valve core component 4 to be connected in a limited manner. Specifically, as shown in the figure... Figure 1 , Figure 4 , Figure 5 As shown, the valve stem 21 extends into the receiving cavity 4111 of the valve core 41, so that the second limiting part 211 is completely located within the receiving cavity 4111. At this time, the first limiting part 412 is located above the second limiting part 211, and the projection of the first limiting part 412 covers at least part of the projection of the second limiting part 211. When the valve stem 21 is removed from the receiving cavity 4111 of the valve core 41, the second limiting part 211 can abut against and limit the first limiting part 412. In this way, the valve core 41 and the valve stem 21 can be regarded as an integral part. When the valve core 41 needs to be disassembled, the valve stem 21 can be taken out or put into the valve seat component 3 together with the valve core 41, which facilitates the assembly of the valve core 41.

[0028] like Figure 4 ,5 As shown, the valve core 41 includes a cylindrical portion 411, and a first limiting portion 412 is located above the cylindrical portion 411. The first limiting portion 412 protrudes inward toward the receiving cavity 4111 relative to the inner wall of the cylindrical portion 411. That is, the first limiting portion 412 is a constricted portion relative to the cylindrical portion 411, and the inner diameter of the first limiting portion 412 is smaller than the inner diameter of the cylindrical portion 411. The valve stem 21 includes a main body portion 212, and a second limiting portion 211 protrudes radially outward relative to the outer wall of the main body portion 212. The main body portion 212 and the second limiting portion 211 are integral structures. That is, the second limiting portion 211 is an enlarged portion relative to the main body portion 212, and the outer diameter of the second limiting portion 211 is larger than the outer diameter of the main body portion 212. The cylindrical portion 411 includes a receiving cavity 4111, and the outer wall of the second limiting portion 211 is clearance-fitted with the inner wall of the receiving cavity 4111. The first limiting part 412 includes a first limiting surface 4122, and the second limiting part 211 includes a second limiting surface 2112. The first limiting surface 4122 is disposed facing the second limiting surface 2112, and the first limiting surface 4122 can abut against the second limiting surface 2112. It should be noted that during disassembly and assembly, the first limiting surface 4122 can abut against the second limiting surface 2112 for limiting, but during the switching process of the check valve, the first limiting surface 4122 and the second limiting surface 2112 do not need to be in contact. Let A1 be the wall thickness of the first limiting part 412 and A2 be the wall thickness of the cylindrical part 411. Then A2 is greater than A1. It should be noted that the valve stem 21 extends into the receiving cavity 4111 of the valve core 41, so that the outer wall of the second limiting part 211 slides with the inner wall of the receiving cavity 4111. Furthermore, the second limiting part 211 is completely located in the receiving cavity 4111. The first limiting part 412 is obtained by riveting. Therefore, the wall thickness of the first limiting part 412 is smaller than the wall thickness of the cylindrical part 411, which is beneficial to riveting. On the one hand, it can reduce the riveting force and facilitate the formation of the riveting neck. On the other hand, the smaller wall thickness has better ductility after riveting, preventing riveting cracks and improving product reliability.

[0029] like Figure 6 , Figure 7The following is another embodiment of this application. The wall thickness of the first limiting part 412A is defined as A11, and the wall thickness of the cylindrical part 411 is defined as A2, then A11 is greater than A2. The first limiting part 412A includes an internal thread section, and the second limiting part 211A includes an external thread section. The internal thread section of the first limiting part 412A and the external thread section of the second limiting part 211A are engaged by threads. It should be noted that the first limiting part 412A is provided with an internal thread, and the second limiting part 211A is provided with an external thread. The first limiting part 412A and the second limiting part 211A are assembled by means of thread engagement. When the external thread section of the second limiting part 211A is fully inserted into the receiving cavity 4111, that is, when the thread engagement is fully penetrated, the outer side wall of the second limiting part 211A and the inner side wall of the receiving cavity 4111 slide with clearance. When the valve stem 21 is disengaged from the receiving cavity 4111 of the valve core 41, the internal thread of the first limiting part 412A and the external thread of the second limiting part 211A cannot engage without rotational force. In the same way, the valve stem 21 and the valve core 41 can be mutually limited while also sliding with each other.

[0030] like Figure 3 As shown, the stop check valve also includes a valve core sleeve 5, which is fixedly connected to the valve cover 11. In the scheme of this application, the valve core sleeve 5 and the valve cover 11 are fixedly connected by threads. It should be noted that the valve core sleeve 5 and the valve cover 11 can also be fixedly connected by other methods, such as laser welding, furnace welding, etc. Figure 1 , Figure 4 As shown, the valve core sleeve 5 includes a receiving cavity 55, and a cylindrical portion 411 is at least partially located in the receiving cavity 55. The cavity wall of the receiving cavity 55 includes a guide section 53 and a receiving section 54. The inner diameter of the guide section 53 is defined as D1, and the inner diameter of the receiving section 54 is defined as D2, satisfying that D2 is greater than D1. The outer wall of the cylindrical portion 411 slides with the guide section 53. The length of the guide section 53 is defined as L1, and the length of the receiving section 54 is defined as L2, satisfying that L2 is greater than L1. That is, the outer wall of the cylindrical portion 411 does not completely slide with the cavity wall of the receiving cavity 55; only the guide section 53 slides with the outer wall of the cylindrical portion 411. To improve the product's service life, the machining accuracy of the guide section 53 is often high. Higher accuracy results in better guiding effect and a longer product service life, but also increases the machining difficulty. Therefore, reducing the length of the guide section 53 can reduce the machining difficulty.

[0031] like Figure 2 , Figure 4As shown, the valve core sleeve 5 also includes a spring 6, which is sleeved on the outer wall of the valve core sleeve 5. The valve core 41 also includes a base portion 410, the outer diameter of which is larger than the outer diameter of the cylindrical portion 411. The base portion 410 includes a first stepped portion 4100, which includes an upward-facing first stepped surface 4110. The first stepped portion 4100 surrounds the outer wall of the cylindrical portion 411. The outer wall of the valve core sleeve 5 includes a second stepped portion 52, which includes a downward-facing second stepped surface. One end of the spring 6 abuts against the first stepped surface 4110, and the other end of the spring 6 abuts against the second stepped surface 521. With this configuration, one end of the spring 6 abuts against the valve core sleeve 5, and the other end of the spring 6 abuts against the valve core 41. In other words, one end of the spring 6 is fitted onto the outer wall of the first step 4100, and the other end of the spring 6 is fitted onto the outer wall of the second step 52. This arrangement restricts the longitudinal displacement of the spring 6 and also restricts the eccentric displacement of the center of the spring 6, thereby improving the stability of the spring 6. At the same time, it reduces the contact area between the spring 6 and the valve core sleeve 5, avoiding wear between the spring 6 and the valve core sleeve 5 during the opening and closing of the valve core 41, and improving the service life of the spring 6.

[0032] Define the step height of the first step portion 4100 as h1, the step height of the second step portion 52 as h2, and the diameter of the spring wire of the spring 6 as h3. Then, h1 is greater than 1.2h3, and h2 is greater than 1.2h3. The step height of the first step portion 4100 is greater than 1.2 times the diameter of the spring wire of the spring 6, and the step height of the second step portion 52 is greater than 1.2 times the diameter of the spring wire of the spring 6. This setting can effectively provide the limiting space for the spring 6, so that the upper and lower ends of the spring 6 are respectively fitted onto the outer walls of the first step portion 4100 and the outer walls of the second step portion 52. Through the limiting at both ends, the spring 6 is stable and reliable.

[0033] like Figure 3As shown, the cavity wall of the receiving cavity 55 also includes a transition section 56, which is located between the guide section 53 and the receiving section 54. The valve core sleeve 5 includes a pressure relief hole 57, which connects the inner and outer walls of the valve core sleeve 5. The pressure relief hole 57 is located in either the receiving section 54 or the transition section 56. It should be noted that the transition section 56 is designed to facilitate the smooth sliding of the valve core 41 in the receiving cavity 55, especially when the valve core 41 moves downwards, it acts as a guide. On the other hand, the gap between the outer wall of the cylindrical part 411 and the sliding fit of the guide section 53 is small. When impurities in the medium enter this gap, they can easily cause wear or even jamming. The transition section 56, when the valve core 41 slides downwards, can retain some impurities in the medium at the transition section 56, reducing the gap where impurities enter the sliding fit and effectively improving the service life of the product. The outer wall of the cylindrical portion 411 slides in fit with the guide section 53. The pressure relief hole 57 should ideally be avoided in the guide section 53, as burrs or sharp edges are easily generated during machining. If the pressure relief hole 57 is located in the guide section 53, these burrs or sharp edges will scratch the outer wall of the cylindrical portion 411, leading to a rougher finish and reduced valve core 41's performance. Therefore, it is preferable to locate the pressure relief hole 57 in the receiving section 54 or the transition section 56.

[0034] like Figure 4 As shown, the valve stem 21 also includes a third limiting part 213, which protrudes outward relative to the main body 212. The third limiting part 213 is located above the second limiting part 211. The third limiting part 213 includes a conical limiting surface 2131 and a lower abutting surface 2132. The conical limiting surface 2131 can abut against the valve cover 11 for limiting, and the lower abutting surface 2132 can abut against the first limiting part 412 for limiting. This configuration limits the upward displacement of the valve stem 21 on the one hand, and the conical limiting surface 2131 abuts against the valve cover 11 on the other hand, achieving a seal between the valve stem 21 and the valve cover 11.

[0035] like Figure 8 , Figure 9 As shown, the valve seat component 3 includes a valve seat body 31, which includes a valve port 310, a valve cavity 320, a fluid inlet 330, and a fluid outlet 340. In the first working state of the check valve, the stepped surface of the first step 4100 abuts against the valve core sleeve 5, the conical limiting surface 2131 abuts against the valve cover 11, the valve core 41 moves away from the valve port 310, and the fluid inlet 330, valve cavity 320, and fluid outlet 340 are connected. This state is the open valve state. The pressure in the system flows in through the fluid inlet 330. Under the action of the fluid pressure, the valve core 41 moves upward and away from the valve port 310. The valve cover 11 and valve stem 21 are hard sealed, and the fluid flows through the valve cavity 320 to the fluid outlet 340.

[0036] like Figure 1As shown, in the second operating state of the check valve, the valve core 41 abuts against the valve port 310, the conical limiting surface 2131 abuts against the valve cover 11, and the fluid inlet 330 is not connected to the valve chamber 320. This state is either the closed valve state or the check valve state. When no high-pressure fluid enters the fluid inlet 330 in the system, the valve core 41 moves downward under its own gravity until it contacts the valve port 310. With the elastic force of the spring 6, the valve core 41 abuts against the valve port 310. If fluid enters the valve chamber 320 from the fluid outlet 340, the pressure of the fluid will increase the contact force between the valve core 41 and the valve port 310, and the valve core 41 will not be able to be opened. If fluid enters the valve chamber 320 from the fluid inlet 330, the pressure of the fluid will push the valve core 41 away from the valve port 310, and the fluid will enter the valve chamber 320 from the fluid inlet 330 and flow out from the fluid outlet 340.

[0037] like Figure 10 As shown, in the third operating state of the check valve, the valve core 41 abuts against the valve port 310, the end of the second limiting part 211 abuts against the bottom of the cylindrical part 411, the conical limiting surface 2131 is away from the valve cover 11, and the fluid inlet 330 is not connected to the valve chamber 320. This state is the shut-off state. In this state, based on the valve being closed, by adjusting the valve stem 21 to abut against the valve core 41, the valve core 41 will not be opened by fluid pressure. In the system, if a component or part of the pipeline needs maintenance, this operating state is often required to ensure that high-pressure fluid does not flow out, thus ensuring safety during maintenance.

[0038] It should be noted that the shut-off check valve is connected to the system via a pipeline, which is often welded. During disassembly, the first limiting part 412 can abut against the second limiting part 211, and the valve stem 21 can drive the valve core 41 to detach from the valve seat component 3, facilitating disassembly and maintenance.

[0039] The above examples illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely illustrative of the method (which may need to be modified into a technical solution) and its core ideas. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A shut-off check valve, comprising: The valve stem assembly (2), valve seat assembly (3), and valve core assembly (4) are provided. The valve stem assembly (2) is connected to the valve core assembly (4) in a limiting manner. The valve core assembly (4) includes a valve core (41), which includes a first limiting part (412). The valve stem assembly (2) includes a valve stem (21), which includes a second limiting part (211). The first limiting part (412) is located above the second limiting part (211) along the longitudinal direction of the check valve. The projection of the first limiting part (412) covers at least a portion of the projection of the second limiting part (211), and the valve core (41) includes a receiving cavity (4111) in which the second limiting part (211) is located.

2. The shut-off check valve according to claim 1, characterized in that, The valve core (41) further includes a cylindrical portion (411), the first limiting portion (412) is located above the cylindrical portion (411), the first limiting portion (412) protrudes into the receiving cavity (4111) relative to the inner wall of the cylindrical portion (411), the valve stem (21) includes a main body portion (212), the second limiting portion (211) protrudes outward relative to the outer wall of the main body portion (212), and the main body portion (212) and the second limiting portion (211) are an integral structure.

3. The shut-off check valve according to claim 1, characterized in that, The valve core (41) further includes a cylindrical portion (411), the cylindrical portion (411) includes the receiving cavity (4111), the first limiting portion (412) is located above the cylindrical portion (411), the first limiting portion (412) protrudes into the receiving cavity (4111) relative to the inner wall of the cylindrical portion (411), the valve stem (21) includes a main body portion (212), the second limiting portion (211) protrudes outward relative to the outer wall of the main body portion (212), the outer wall of the second limiting portion (211) slides with the inner wall of the cylindrical portion (411), and the main body portion (212) and the second limiting portion (211) are an integral structure.

4. The shut-off check valve according to any one of claims 1-3, characterized in that, The first limiting part (412) includes a first limiting surface (4122), and the second limiting part (211) includes a second limiting surface (2112). The first limiting surface (4122) is disposed facing the second limiting surface (2112). The first limiting surface (4122) can abut against the second limiting surface (2112). The wall thickness of the first limiting part (412) is defined as A1, and the wall thickness of the cylindrical part (411) is defined as A2, then A2 is greater than A1.

5. The shut-off check valve according to claim 3 or 4, characterized in that, The wall thickness of the first limiting part (412A) is defined as A11, and the wall thickness of the cylindrical part (411) is defined as A2. Then A11 is greater than A2. The first limiting part (412A) includes an internal thread section, and the second limiting part (211A) includes an external thread section. The internal thread section of the first limiting part (412A) and the external thread section of the second limiting part (211A) are threadedly engaged.

6. The shut-off check valve according to any one of claims 1-5, characterized in that, It also includes a valve cover component (1) and a valve core sleeve (5). The valve cover component (1) is detachably connected to the valve seat component (3). The valve cover component (1) includes a valve cover (11). The valve core sleeve (5) is fixedly connected to the valve cover (11). The valve core sleeve (5) includes a receiving cavity (55). The cylindrical part (411) is at least partially located in the receiving cavity (55). The cavity wall of the receiving cavity (55) includes a guide section (53) and a receiving section (54). The inner diameter of the guide section (53) is defined as D1, and the inner diameter of the receiving section (54) is defined as D2. Then, D2 is greater than D1. The outer wall of the cylindrical part (411) is in sliding fit with the guide section (53).

7. The shut-off check valve according to claim 6, characterized in that, It also includes a spring (6), which is sleeved on the outer wall of the valve core sleeve (5). The valve core (41) also includes a base portion (410), the outer diameter of which is larger than the outer diameter of the cylindrical portion (411). The base portion (410) includes a first stepped portion (4100), which includes an upwardly facing first stepped surface (4110). The first stepped portion (4100) is disposed around the outer side wall of the cylindrical portion (411). The outer side wall of the valve core sleeve (5) includes a second stepped portion (52), which includes a downwardly facing second stepped surface (521). One end of the spring (6) abuts against the first stepped surface (4110), and the other end of the spring (6) abuts against the second stepped surface (521).

8. The shut-off check valve according to claim 7, characterized in that, Define the step height of the first step (4100) as h1, define the step height of the second step (52) as h2, and define the wire diameter of the spring (6) as h3. Then, h1 is greater than 1.2h3 and h2 is greater than 1.2h3.

9. The shut-off check valve according to any one of claims 6-8, characterized in that, The cavity wall of the receiving cavity (55) further includes a transition section (56), which is located between the guide section (53) and the receiving section (54). The valve core sleeve (5) includes a pressure relief hole (57), which connects the inner wall and the outer wall of the valve core sleeve (5). The pressure relief hole (57) is located in the transition section (56) or the receiving section (54).

10. The shut-off check valve according to any one of claims 6-8, characterized in that, The valve stem (21) further includes a third limiting part (213), which protrudes outward in the circumferential direction relative to the main body part (212). The third limiting part (213) is located above the second limiting part (211). The third limiting part (213) includes a conical limiting surface (2131) and a lower abutting surface (2132). The conical limiting surface (2131) can abut against the valve cover (11) for limiting, and the lower abutting surface (2132) can abut against the first limiting part (412) for limiting.

11. The shut-off check valve according to claim 7, characterized in that, The valve seat component (3) includes a valve seat body (31), which includes a valve port (310), a valve cavity (320), a fluid inlet (330), and a fluid outlet (340). When the shut-off check valve is in its first working state, the stepped surface of the first stepped portion (4100) abuts against the valve core sleeve (5), the conical limiting surface (2131) abuts against the valve cover (11), the valve core (41) is away from the valve port (310), and the fluid inlet (330), the valve cavity (320), and the fluid outlet (340) are connected. When the check valve is in the second working state, the valve core (41) abuts against the valve port (310), the conical limiting surface (2131) abuts against the valve cover (11), and the fluid inlet (330) is not connected to the valve cavity (320); when the check valve is in the third working state, the valve core (41) abuts against the valve port (310), the end of the second limiting part (211) abuts against the bottom of the cylindrical part (411), the conical limiting surface (2131) is away from the valve cover (11), and the fluid inlet (330) is not connected to the valve cavity (320).

12. A shut-off check valve, comprising: The valve stem assembly (2), valve seat assembly (3), and valve core assembly (4) are connected in a limiting manner. The valve stem assembly (2) includes a valve stem (21), and the valve core assembly (4) includes a valve core (41). The valve core (41) includes a first limiting part (412), and the valve stem (21) includes a second limiting part (211). The first limiting part (412) is located above the second limiting part (211) and extends along the stop valve. In the longitudinal direction of the valve, the projection of the first limiting part (412) covers at least part of the projection of the second limiting part (211). The valve core (41) includes a receiving cavity (4111), and the second limiting part (211) is located in the receiving cavity (4111). During the removal of the shut-off check valve, the first limiting part (412) can abut against the second limiting part (211), and the valve stem (21) can drive the valve core (41) to detach from the valve seat component (3).

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