Axial-flow check valve capable of balancing gravity center of valve disc

Abstract

An axial-flow check valve capable of balancing the gravity center of a valve disc. The axial-flow check valve comprises a valve body (1), wherein a channel (11) allowing a medium to flow therethrough is formed in the valve body; a supporting frame (2) is provided in the channel, and a through hole is formed in the supporting frame in a manner of penetrating in the flow direction of the medium; in the through hole, a valve disc (3) is connected in a sliding manner in the flow direction of the medium, and an elastic member (4) is provided between the valve disc and the supporting frame; and the end of the valve disc away from an inlet end of the channel extends out of the supporting frame and is provided with a counterweight member (5), the counterweight member being configured to maintain the gravity center of the valve disc in the through hole. The axial-flow check valve can prevent the valve disc from sagging in the valve disc opening and closing process, such that the valve disc opening and closing process is more smooth, the opening resistance is relatively small, the response is more timely, and the sealing performance is more excellent, thereby ensuring the operation reliability and stability of a nuclear power pipeline assembled with the axial-flow check valve.

Description

An axial flow check valve capable of balancing the center of gravity of the valve disc

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the Patent Office of China on March 22, 2024, with application number 202410333545.8 and invention name “A axial flow check valve capable of balancing the center of gravity of the valve disc”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of valve technology, and in particular to an axial flow check valve capable of balancing the center of gravity of a valve disc. Background Art

[0004] Axial flow check valves are high-performance check valves characterized by timely response, resistance to water hammer, and minimal pressure loss. They are particularly well-suited for pipelines connected to nuclear power plants, where demanding operating conditions place high demands on their opening and closing performance, opening characteristics, safety features, and sealing properties.

[0005] At present, most axial flow check valves used in pipelines in the nuclear power field tend to have the center of gravity of the valve disc move forward easily during closing operation, resulting in a drooping phenomenon. This can easily cause the valve disc to open and close unsmoothly, with large opening resistance, poor sealing performance, severe local strain on the guide pair, and short service life.

[0006] Summary of the Invention

[0007] Therefore, the technical problem to be solved by this application is to overcome the defects of the axial flow check valve in the prior art, in which the center of gravity of the valve disc easily moves forward during the closing operation, forming a drooping phenomenon, which easily causes the valve disc to open and close smoothly, with large opening resistance, poor sealing performance, severe local strain on the guide pair, and short service life, thereby providing an axial flow check valve that can balance the center of gravity of the valve disc.

[0008] According to the present application, an axial flow check valve capable of balancing the center of gravity of a valve disc is provided, which is applied to nuclear power pipelines. The axial flow check valve comprises:

[0009] The valve body is provided with a channel for the medium to flow through;

[0010] A support frame is arranged in the channel, and a through hole is formed on the support frame along the flow direction of the medium;

[0011] The valve flap is slidably connected to the through hole along the flow direction of the medium, and an elastic member is provided between the valve flap and the support frame; the end of the valve flap away from the inlet end of the channel extends outside the support frame and is provided with a counterweight, which is used to keep the center of gravity of the valve flap in the through hole.

[0012] The axial flow check valve capable of balancing the center of gravity of the valve disc according to the present application has at least the following technical effects:

[0013] 1. By extending one end of the valve disc away from the inlet end of the channel to the outside of the support frame and providing a counterweight, relative to the existing valve disc structure, the counterweight of the axial flow check valve causes the center of gravity of the whole composed of the valve disc and the counterweight to shift toward the direction close to the counterweight, ensuring that during the process of opening and closing the valve disc of the axial flow check valve, the center of gravity of the whole composed of the valve disc and the counterweight always remains in the through hole, avoiding the formation of a drooping phenomenon during the opening and closing process of the valve disc, ensuring that the opening and closing process of the valve disc is smoother, the response is more timely, the sealing performance is better, and the reliability and stability of the operation of the nuclear power pipeline equipped with the axial flow check valve are ensured.

[0014] 2. By arranging an elastic member between the valve disc and the support frame, when the external force applied to the valve disc is less than the elastic restoring force of the elastic member, the valve disc can be driven to accurately and automatically reset to achieve the specified function.

[0015] Optionally, an external threaded portion is provided on an outer side wall of one end of the valve disc facing the counterweight, and a first internal threaded hole is provided on an end surface of the counterweight facing the valve disc, and the first internal threaded hole matches the external threaded portion.

[0016] Optionally, a mounting groove is recessed on the end surface of the support frame facing the counterweight, one end of the elastic member abuts against the end surface of the counterweight facing the support frame, and the other end of the elastic member abuts against the inner bottom wall of the mounting groove.

[0017] Optionally, the external threaded portion is threadedly connected to a limit seat, and one end of the elastic member facing away from the mounting groove abuts against the limit seat.

[0018] Optionally, a second internal threaded hole is provided on the limit seat, and a T-slot is recessed on the outer side wall of the counterweight piece at one end facing the limit seat, the horizontal portion of the T-slot is located at one end of the counterweight piece facing the vertical portion of the T-slot, and the horizontal portion of the T-slot passes through the counterweight piece along the flow direction of the medium and corresponds to the second internal threaded hole; when connected, the hexagon socket screw is embedded in the T-slot and threadedly connected to the second internal threaded hole.

[0019] Optionally, a locking ring is provided between the limiting seat and the counterweight, and the second internal threaded hole is provided on the locking ring.

[0020] Optionally, a through-hole is formed on the counterweight along the medium flow direction, the through-hole is connected to the vertical portion of the T-slot and is used for passing a hexagonal wrench; the diameter of the through-hole is smaller than the outer diameter of the screw head of the hexagonal screw;

[0021] And / or, a circle of positioning grooves is concavely provided on the external threaded portion, a split ring is embedded in the positioning groove, and the end surface of the split ring facing the locking ring abuts against the locking ring;

[0022] And / or, a thrust pad is provided between the inner bottom wall of the mounting groove and the elastic member, and the end surface of the thrust pad facing the elastic member is provided as a smooth surface.

[0023] Optionally, an anti-rotation groove is provided on the outer side wall of the support frame, an anti-rotation hole is provided on the inner wall of the channel at a position corresponding to the anti-rotation groove, an anti-rotation pin is provided in the anti-rotation hole, and one end of the anti-rotation pin extends outside the anti-rotation hole and is clamped in the anti-rotation groove;

[0024] And / or, a first hard wear-resistant layer is provided on the inner wall of the through hole;

[0025] and / or, a second hard wear-resistant layer is provided on the outer side wall of the valve disc;

[0026] And / or, a limiting portion is protruded from the inner wall of the channel toward the center of the channel, one end of the support frame abuts against the limiting portion, and an end of the support frame facing away from the limiting portion abuts against a retaining ring, and the retaining ring is connected to the inner wall of the channel;

[0027] And / or, the channel is configured as a Venturi streamlined channel.

[0028] Optionally, the valve flap includes a guide rod and a flap head, the guide rod is slidably connected to the through hole along the flow direction of the medium, and the counterweight is arranged on the guide rod; one end of the guide rod facing the inlet end of the channel extends to the outside of the support frame and is connected to the flap head, and the cross-sectional area of ​​the flap head perpendicular to the flow direction of the medium is larger than the cross-sectional area of ​​the guide rod perpendicular to the flow direction of the medium; a plurality of flow holes are arranged on the support frame at intervals along the circumferential direction, the flow holes pass through the support frame along the direction of the medium, and the projection of the flow holes along the flow direction of the medium falls within the range of the flap head.

[0029] Optionally, a sealing seat ring is provided on the end surface of the inlet end of the channel facing the valve disc; when the check valve is in a closed state, the disc head abuts against the sealing seat ring.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] FIG1 is a schematic structural diagram of an axial flow check valve capable of balancing the center of gravity of a valve disc according to an embodiment of the present invention;

[0033] FIG2 is a partially enlarged schematic diagram of FIG1 .

[0034] Description of reference numerals:

[0035] 1-valve body, 11-channel, 111-limiting part, 12-sealing seat ring;

[0036] 2-support frame, 21-mounting slot, 22-thrust pad, 23-anti-rotation slot, 24-anti-rotation pin, 25-retaining ring, 26-flow hole;

[0037] 3-valve disc, 31-guide rod, 32-valve head;

[0038] 4- elastic member;

[0039] 5-counterweight, 51-limiting seat, 52-hexagon socket screw, 53-locking ring, 54-split ring;

[0040] 6-Short tube. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solution of this application in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0042] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0044] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0045] As shown in Figures 1 and 2, an axial flow check valve provided in this embodiment that can balance the center of gravity of a valve disc is used in nuclear power pipelines. The axial flow check valve includes a valve body 1, wherein a channel 11 for medium flow is provided in the valve body 1; a support frame 2 is provided in the channel 11, and a through hole is formed on the support frame 2 along the flow direction of the medium; a valve disc 3 is slidably connected in the through hole along the flow direction of the medium, and an elastic member 4 is provided between the valve disc 3 and the support frame 2; the end of the valve disc 3 that is away from the inlet end of the channel 11 extends to the outside of the support frame 2 and is provided with a counterweight 5, which is used to maintain the center of gravity of the valve disc 3 within the through hole. It can be understood that the medium flow direction described in this embodiment refers to the medium flow direction in Figure 1.

[0046] The axial flow check valve of this embodiment extends the end of the valve disc 3 away from the inlet end of the channel 11 to the outside of the support frame 2 and is provided with a counterweight 5. Compared with the existing valve disc structure, the counterweight 5 of the axial flow check valve of this embodiment makes the center of gravity of the whole composed of the valve disc 3 and the counterweight 5 shift toward the direction close to the counterweight 5, ensuring that during the process of opening and closing the valve disc 3 of the axial flow check valve of this embodiment, the center of gravity of the whole composed of the valve disc 3 and the counterweight 5 always remains in the through hole (that is, the center of gravity of the whole composed of the valve disc 3 and the counterweight 5 is always located within the guide length of the support frame 2 and the valve disc 3), avoiding the formation of a drooping head phenomenon during the opening and closing process of the valve disc 3, ensuring that the opening and closing process of the valve disc 3 is smoother, the opening resistance is smaller, the response is more timely, and the sealing performance is better, thereby ensuring the reliability and stability of the operation of the nuclear power pipeline equipped with the axial flow check valve of this embodiment. An elastic member 4 is also provided between the valve flap 3 and the support frame 2. When the external force applied to the valve flap 3 is less than the elastic restoring force of the elastic member 4, the valve flap 3 can be driven to automatically reset accurately to achieve the specified function.

[0047] Optionally, a short pipe 6 is welded to the outlet end of the channel 11 so as to be assembled with a nuclear power pipeline to form a pipeline system.

[0048] Optionally, an externally threaded portion is provided on the outer wall of the end of the valve disc 3 facing the counterweight 5, and a first internally threaded hole is provided on the end surface of the counterweight 5 facing the valve disc 3, the first internally threaded hole matching the externally threaded portion. The counterweight 5 and valve disc 3 are assembled integrally by a removable threaded connection between the first internally threaded and externally threaded portions. This facilitates replacement of the counterweight 5 with a corresponding weight for connection to the valve disc 3 as needed. Furthermore, the threaded engagement force of the first internally threaded and externally threaded portions ensures a secure connection between the counterweight 5 and valve disc 3. As an alternative to the above technical solution, the counterweight 5 is embedded within the end of the valve disc 3 facing away from the inlet of the passage 11. The density of the counterweight 5 is greater than that of the valve disc 3. This also allows the center of gravity of the valve disc 3 and counterweight 5 assembly to shift toward the counterweight 5, ensuring that the center of gravity of the valve disc 3 and counterweight 5 assembly remains within the through-hole during opening and closing of the valve disc 3 of this embodiment.

[0049] As shown in Figures 1 and 2, optionally, a mounting groove 21 is recessed on the end surface of the support frame 2 facing the counterweight 5, one end of the elastic member 4 abuts against the end surface of the counterweight 5 facing the support frame 2, and the other end of the elastic member 4 abuts against the inner bottom wall of the mounting groove 21. By designing the elastic member 4 in an inverted manner and installing it between the end surface of the support frame 2 facing away from the inlet end of the channel 11 and the counterweight 5, the axial flow check valve of this embodiment is in a normally open free state, ensuring that the valve flap 3 is in a fully open state in a natural state. When the reverse flow medium force applied to the back of the valve flap 3 is greater than the elastic force of the elastic member 4, the medium can drive the valve flap 3 to perform a precise closing action, thereby achieving the function of blocking the flow of reverse flow medium, thereby meeting the specific functional requirements of the nuclear power pipeline system. At the same time, a mounting groove 21 is recessed on the end surface of the support frame 2 facing the counterweight 5. The mounting groove 21 limits and guides the end of the elastic member 4 away from the counterweight 5, so that the elastic member 4 is compressed or reset along the straight line of the medium flow direction during the opening and closing process of the valve flap 3, ensuring that the opening and closing process of the valve flap 3 is smoother and the response is more timely.

[0050] Optionally, the elastic member 4 is configured as a coil spring. When compressed, the coil spring can better store energy, ensuring that the preload pressure provided by the coil spring to the valve flap 3, which pulls the valve flap 3 toward the inlet end away from the channel 11, remains stable. This maintains the axial flow check valve of this embodiment in a normally open, free state, thereby meeting the specific functional requirements of nuclear power pipeline systems. As an alternative to the above technical solution, the elastic member 4 is configured as a straight cylindrical portion made of an elastic material (such as spring steel).

[0051] As shown in Figure 2, optionally, a limit seat 51 is threadedly connected to the external threaded portion, and the end of the elastic member 4 away from the mounting groove 21 abuts against the limit seat 51. The limit seat 51 limits the position of the end of the elastic member 4 away from the mounting groove 21, which facilitates the installation of the counterweight 5, the locking ring 53, and the split ring 54. At the same time, it can prevent the elastic member 4 from expanding and contracting along with the counterweight 5 during the process of disassembling and assembling the counterweight 5. There is no need to retest the opening and closing pressure of the elastic member 4 of the check valve after the counterweight 5 is disassembled and reinstalled, thereby simplifying the process. At the same time, the limit seat 51 is threadedly connected to the external threaded portion, and the distance between the limit seat 51 and the inner bottom wall of the mounting groove 21 along the medium flow direction can be steplessly adjusted, thereby steplessly adjusting the pre-compression amount of the elastic member 4, and then flexibly adjusting the opening and closing pressure of the axial flow check valve of this embodiment, which can adapt to different use environments with different opening and closing pressures and has strong applicability.

[0052] Optionally, a second internal threaded hole is provided on the limit seat 51, and a T-slot is recessed on the outer side wall of one end of the counterweight 5 facing the limit seat 51. The horizontal portion of the T-slot is located at one end of the vertical portion of the T-slot facing the limit seat 51. The horizontal portion of the T-slot passes through the counterweight 5 along the flow direction of the medium and corresponds to the second internal threaded hole. When connected, the hexagon socket screw 52 is embedded in the T-slot and threaded into the second internal threaded hole. The threaded connection between the hexagon socket screw 52 and the second internal threaded hole allows the counterweight 5 and the limit seat 51 to be tightened and connected as one, more effectively avoiding the risk of the counterweight 5 falling from the valve disc 3 into the channel 11 and entering the nuclear power pipeline with the flow of the medium, fully ensuring the safe and stable operation of the nuclear power pipeline system equipped with the axial flow check valve of this embodiment.

[0053] As shown in FIG2 , optionally, a locking ring 53 is provided between the limit seat 51 and the counterweight 5, and the second internal threaded hole is provided on the locking ring 53. By adding the locking ring 53 between the limit seat 51 and the counterweight 5, it is ensured that the rotation of the limit seat 51 and the counterweight 5 does not interfere with each other without removing the hexagon socket screw 52. When the screw head of the hexagon socket screw 52 loosens and moves in a direction away from the second internal threaded hole to abut the inner wall of the vertical portion of the T-slot away from the horizontal portion of the T-slot, because the tip of the hexagon socket screw 52 is still partially located in the second internal threaded hole, the risk of the hexagon socket screw 52 falling into the channel 11 due to loosening and entering the nuclear power pipeline with the flow of the medium can be effectively avoided, thereby fully ensuring the safe and stable operation of the nuclear power pipeline system equipped with the axial flow check valve of this embodiment. When it is necessary to remove the hexagon socket screw 52, ​​first rotate the limit seat 51 in the direction away from the counterweight 5. At this time, the limit seat 51 and the locking ring 53 have a non-zero spacing along the medium flow direction. Then loosen the hexagon socket screw 52 slightly in the direction close to the counterweight 5. Then move the locking ring 53 together with the hexagon socket screw 52 in the direction away from the counterweight 5. Repeat this operation until the hexagon socket screw 52 is completely out of the second internal threaded hole. Finally, remove the hexagon socket screw 52 from the T-slot. It can be understood that when the screw head of the hexagon socket screw 52 is loosened and moved to the inner wall of the vertical part of the T-slot away from the horizontal part of the T-slot, the hexagon socket screw 52 is connected to the second internal threaded hole in a threaded manner.

[0054] Optionally, a perforation is formed through the counterweight 5 along the medium flow direction, the perforation being connected to the vertical portion of the T-slot and being used to pass a hexagonal wrench through; the diameter of the perforation is smaller than the outer diameter of the head of the hexagonal screw 52. The perforation provides space for the hexagonal wrench to extend to the vertical portion of the T-slot, so that the hexagonal wrench can be used to thread the hexagonal screw 52 into the second internally threaded hole. At the same time, because the diameter of the perforation is smaller than the outer diameter of the head of the hexagonal screw 52, ​​even if the hexagonal screw 52 becomes loose, it can only be dislodged to the point where the head of the hexagonal screw 52 abuts the inner wall of the vertical portion of the T-slot, away from the horizontal portion of the T-slot, and cannot be loosened further. This effectively prevents the risk of the hexagonal screw 52 falling into the channel 11 due to loosening and entering the nuclear power pipeline with the flow of the medium, fully ensuring the safe and stable operation of the nuclear power pipeline system equipped with the axial flow check valve of this embodiment.

[0055] As shown in FIG2 , the external threaded portion may optionally be provided with a circle of positioning grooves, into which a split ring 54 is embedded. The end surface of the split ring 54 facing the locking ring 53 abuts against the locking ring 53. The split ring 54 restricts the freedom of movement of the locking ring 53 away from the limiting seat 51, thereby preventing the locking ring 53 from falling out and ensuring that when the counterweight 5 is threadedly connected to the set position on the external threaded portion, the T-slot is aligned with the second internal threaded hole to facilitate installation of the hexagon socket screw 52.

[0056] As shown in FIG2 , a thrust pad 22 is optionally provided between the inner bottom wall of the mounting groove 21 and the elastic member 4. The end surface of the thrust pad 22 facing the elastic member 4 is configured as a smooth surface. The thrust pad 22 reduces friction between the elastic member 4 and the thrust pad 22, effectively reducing resistance to circumferential rotation of the valve flap 3. This meets the functional requirements for the rotation of the valve flap 3 while effectively preventing distortion of the elastic member 4 due to high torsional resistance.

[0057] As shown in FIG2 , an anti-rotation groove 23 is optionally provided on the outer wall of the support frame 2, and an anti-rotation hole is provided on the inner wall of the channel 11 at a position corresponding to the anti-rotation groove 23. An anti-rotation pin 24 is provided in the anti-rotation hole, and one end of the anti-rotation pin 24 extends outside the anti-rotation hole and is engaged in the anti-rotation groove 23. The anti-rotation pin 24 effectively prevents the support frame 2 from rotating within the channel 11 during operation of the axial flow check valve of this embodiment, thereby improving the stability and reliability of the operation of the axial flow check valve of this embodiment.

[0058] As shown in FIG2 , the inner wall of the channel 11 optionally includes a stopper 111 projecting toward the center of the channel 11. One end of the support frame 2 abuts the stopper 111, while the end of the support frame 2 facing away from the stopper 111 abuts a retaining ring 25, which is connected to the inner wall of the channel 11. The stopper 111 precisely positions the support frame 2 within the channel 11. The stopper 111 and the retaining ring 25 cooperate to restrict the freedom of movement of the support frame 2 along the flow direction of the medium, thereby improving the operational reliability of the axial flow check valve of this embodiment. Specifically, a circle of stopper grooves is recessed on the inner wall of the channel 11, corresponding to the position of the retaining ring 25. The outer side of the retaining ring 25 is embedded in the stopper grooves. The stopper grooves position and restrict the position of the retaining ring 25, thereby effectively limiting the freedom of movement of the support frame 2 in a direction away from the stopper 111.

[0059] Optionally, a first hard wear-resistant layer is provided on the inner wall of the through hole, which improves the wear resistance of the inner wall of the through hole and prolongs the service life.

[0060] Optionally, a second hard wear-resistant layer is provided on the outer side wall of the valve flap 3. The second hard wear-resistant layer improves the wear resistance of the valve flap 3 and prolongs its service life.

[0061] Optionally, the channel 11 is configured as a Venturi streamlined channel with low pressure drop and small flow resistance, so that when the medium flows through the channel 11, the pressure loss is minimized to the greatest extent.

[0062] As shown in Figures 1 and 2, optionally, the valve flap 3 includes a guide rod 31 and a flap head 32, the guide rod 31 is slidably connected in the through hole along the flow direction of the medium, and the counterweight 5 is arranged on the guide rod 31; the guide rod 31 extends to the outside of the support frame 2 at one end toward the inlet end of the channel 11 and is connected to the flap head 32, and the cross-sectional area of ​​the flap head 32 perpendicular to the flow direction of the medium is larger than the cross-sectional area of ​​the guide rod 31 perpendicular to the flow direction of the medium; a plurality of flow holes 26 are arranged on the support frame 2 at intervals along the circumferential direction, and three flow holes 26 can be optionally provided here, and the flow holes 26 pass through the support frame 2 along the direction of the medium, and the projection of the flow holes 26 along the flow direction of the medium falls within the range of the flap head 32. By adding three flow holes 26 evenly distributed along the circumference on the support frame 2, when the reverse-flowing fluid medium flows toward the inlet end of the channel 11, the force applied by the reverse-flowing fluid medium to the flap head 32 and pushing the flap head 32 to move in the direction away from the support frame 2 can be increased, which is conducive to the rapid closing of the valve flap 3 and accurately realizes the function of blocking the circulation of the reverse-flowing medium.

[0063] As shown in FIG1 , a sealing seat ring 12 is optionally provided at the inlet end of the channel 11, facing the end surface of the valve disc 3. When the check valve is in the closed state, the disc head 32 abuts against the sealing seat ring 12. The sealing seat ring 12 improves the abutment sealing effect with the disc head 32, thereby improving the sealing effect on the inlet end of the channel 11 and ensuring the blocking effect of reverse flow of medium.

[0064] Optionally, the valve flap 3 and the support frame 2 form a water drop shape, and a tail wing structure is designed at the tail end of the support frame 2 away from the inlet end of the channel 11 to avoid vibration and swirl caused by internal and external diversion, reduce flow resistance, improve flow field stability, and reduce noise.

[0065] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of this application.

Claims

1. An axial flow check valve capable of balancing the center of gravity of the valve disc, used in nuclear power pipelines, characterized in that: The axial flow check valve comprises: The valve body (1) is provided with a channel (11) for the medium to flow through; A support frame (2) is arranged in the channel (11), and a through hole is formed on the support frame (2) along the flow direction of the medium; A valve flap (3) is slidably connected in the through hole along the flow direction of the medium, and an elastic member (4) is provided between the valve flap (3) and the support frame (2); an end of the valve flap (3) away from the inlet end of the channel (11) extends outside the support frame (2), and a counterweight (5) is provided, and the counterweight (5) is used to maintain the center of gravity of the valve flap (3) in the through hole.

2. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 1, characterized in that: An external threaded portion is provided on the outer side wall of one end of the valve flap (3) facing the counterweight (5), and a first internal threaded hole is provided on the end surface of the counterweight (5) facing the valve flap (3), and the first internal threaded hole matches the external threaded portion.

3. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 2, characterized in that: The end surface of the support frame (2) facing the counterweight (5) is concavely provided with a mounting groove (21); one end of the elastic member (4) abuts against the end surface of the counterweight (5) facing the support frame (2); and the other end of the elastic member (4) abuts against the inner bottom wall of the mounting groove (21).

4. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 3, characterized in that: The external threaded portion is threadedly connected to a limiting seat (51), and one end of the elastic member (4) facing away from the mounting groove (21) abuts against the limiting seat (51).

5. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 4, characterized in that: A second internal threaded hole is provided on the limiting seat (51), and a T-shaped slot is recessed on the outer side wall of one end of the counterweight (5) facing the limiting seat (51). The horizontal portion of the T-shaped slot is located at one end of the vertical portion of the T-shaped slot facing the limiting seat (51). The horizontal portion of the T-shaped slot passes through the counterweight (5) along the flow direction of the medium and corresponds to the second internal threaded hole. When connected, the hexagon socket screw (52) is embedded in the T-shaped slot and is threadedly connected in the second internal threaded hole.

6. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 5, characterized in that: A locking ring (53) is provided between the limiting seat (51) and the counterweight (5), and the second internal threaded hole is provided on the locking ring (53).

7. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 6, characterized in that: The counterweight (5) is provided with a through hole along the medium flow direction, the through hole being connected to the vertical portion of the T-slot and being used for passing a hexagonal wrench through; the diameter of the through hole is smaller than the outer diameter of the screw head of the hexagonal screw (52); And / or, a circle of positioning grooves is concavely provided on the external threaded portion, a split ring (54) is embedded in the positioning groove, and the end surface of the split ring (54) facing the locking ring (53) abuts against the locking ring (53); And / or, a thrust pad (22) is provided between the inner bottom wall of the installation groove (21) and the elastic member (4), and the end surface of the thrust pad (22) facing the elastic member (4) is provided as a smooth surface.

8. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 1, characterized in that: An anti-rotation groove (23) is provided on the outer wall of the support frame (2), an anti-rotation hole is provided on the inner wall of the channel (11) at a position corresponding to the anti-rotation groove (23), an anti-rotation pin (24) is provided in the anti-rotation hole, and one end of the anti-rotation pin (24) extends outside the anti-rotation hole and is clamped in the anti-rotation groove (23); And / or, a first hard wear-resistant layer is provided on the inner wall of the through hole; and / or, a second hard wear-resistant layer is provided on the outer side wall of the valve flap (3); And / or, a limiting portion (111) is protruded from the inner wall of the channel (11) toward the center of the channel (11), one end of the support frame (2) abuts against the limiting portion (111), and an end of the support frame (2) facing away from the limiting portion (111) abuts against a retaining ring (25), and the retaining ring (25) is connected to the inner wall of the channel (11); And / or, the channel (11) is configured as a Venturi streamlined channel.

9. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 1, characterized in that: The valve flap (3) includes a guide rod (31) and a flap head (32), wherein the guide rod (31) is slidably connected to the through hole along the flow direction of the medium, and the counterweight (5) is arranged on the guide rod (31); one end of the guide rod (31) facing the inlet end of the channel (11) extends to the outside of the support frame (2) and is connected to the flap head (32), and the cross-sectional area of ​​the flap head (32) perpendicular to the flow direction of the medium is larger than the cross-sectional area of ​​the guide rod (31) perpendicular to the flow direction of the medium; a plurality of flow holes (26) are arranged on the support frame (2) at intervals along the circumferential direction, and the flow holes (26) penetrate the support frame (2) along the direction of the medium, and the projection of the flow holes (26) along the flow direction of the medium falls within the range of the flap head (32).

10. The axial flow check valve capable of balancing the center of gravity of the valve disc according to claim 9, characterized in that: A sealing seat ring (12) is provided at the inlet end of the channel (11) facing the end surface of the valve disc (3); when the check valve is in a closed state, the disc head (32) abuts against the sealing seat ring (12).

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