Swing check valve with built-in slow closing structure

Abstract

The utility model relates to a swing check valve with a built-in slow-closing structure, which comprises a valve body, a valve clack, a rocker arm, a shifting fork and a valve cover, the rocker arm is connected with the shifting fork through a cylindrical pin, the rocker arm can drive the valve clack to rotate, a slow closing device is arranged in the valve body and comprises a supporting shaft, a support and a hook, and the support is of a hollow structure so that the valve clack can be normally opened and closed. U-shaped holes are formed in the two sides of the support, and the supporting shaft and the hook are placed in the U-shaped holes; an extension spring is arranged between the supporting shaft and the hook; and a sleeve is sleeved below the hook. When the valve is in a working state and the valve clack is converted into a closed state from an open state, the valve clack is slowly closed under the action of self weight, backflow pressure and the acting force of the extension spring, the valve clack is prevented from directly and rapidly falling back to be closed, the water hammer effect is avoided, and the service life of the valve is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of gate valve technology, specifically relating to a swing check valve with built-in slow-closing structure. Background Technology

[0002] Swing check valves are one-way valves with advantages such as large opening degree, low cost, and stable reliability. Due to the special internal structure of swing check valves, the valve core inside closes at a relatively fast speed, which will impact the components inside the pipeline, easily accelerating the aging and damage of the parts and causing water hammer, thus reducing their lifespan.

[0003] Most existing slow-closing swing check valves use a counterweight type, with the slow-closing device located outside the valve body. A combination of a rocker arm and a counterweight is installed at the end of the rotating shaft that extends out of the valve body to generate a torque opposite to the closing direction of the valve disc, thereby delaying the closing time of the valve disc. This structure is relatively complex, and penetrating the valve body increases the number of valve leakage points.

[0004] For example, Chinese utility model patent CN 221463016 U discloses a cryogenic swing check valve with free check capability, including a valve body, valve disc, rocker arm, valve disc nut, spring pin I, spring pin II, fork, hook, valve stem, cylindrical pin I, and cylindrical pin II. The valve disc and rocker arm are connected and fixed by the valve disc nut, the rocker arm and fork are connected and fixed by the cylindrical pin, a tension spring is connected between spring pin I and spring pin II, and the valve stem and hook are connected and fixed by hexagonal screws. This check valve is simple to operate and has an ingenious structure. During LNG ship unloading, this check valve can achieve free check. When the unloading arm pipeline is pre-cooled or LNG is being reloaded, the valve disc can be raised by handwheel operation to achieve full-bore flow. However, this valve lacks a slow-closing structure, and the valve disc falls back and closes directly and quickly, causing water hammer effect. Moreover, the overall height is relatively high, requiring an independent platform for on-site operation, and the valve disc lacks a damping device for opening and closing, resulting in significant noise during operation. Summary of the Invention

[0005] To address the problems existing in the prior art, this utility model proposes a swing check valve with a built-in slow-closing structure. By setting a counterweight device and a slow-closing cylinder assembly, the valve stem operating speed is reduced, which has a damping effect and avoids direct impact between the valve disc and the valve body when the valve is opened and closed, thus extending the service life of the valve.

[0006] This utility model proposes a swing check valve with a built-in slow-closing structure, comprising a valve body, a valve disc, a rocker arm, a fork, and a valve cover. The valve disc is fixedly connected to the rocker arm; the rocker arm and the fork are connected by a cylindrical pin, and the rocker arm can drive the valve disc to rotate. A slow-closing device is provided within the valve body, comprising a support shaft, a bracket, and a hook. The bracket has a hollow structure to facilitate the normal opening and closing of the valve disc. U-shaped holes are opened on both sides of the bracket, and the support shaft and hook are placed in the U-shaped holes. A tension spring is provided between the support shaft and the hook, and the force of the tension spring buffers the valve disc when it closes. Different specifications of tension springs can be replaced according to different needs. A sleeve is fitted below the hook. The slow-closing device is located within the valve body, reducing valve leakage points and saving valve installation space. The hollow structure of the bracket in the slow-closing device does not affect the normal opening and closing of the valve disc.

[0007] When the valve is in operation, as the valve disc changes from the open state to the closed state, the valve disc is subjected to its own weight and backflow pressure, as well as the force of the tension spring, thereby achieving slow closure of the valve disc. This prevents the valve disc from falling back to the closed state directly and quickly, avoiding the water hammer effect and improving the service life of the valve.

[0008] Preferably, the slow-closing structure is an internal structure, which reduces leakage points and is simple in structure and easy to install; the slow-closing device is fixedly connected to the inner wall of the valve cover by hexagonal nuts and bolts, and adopts an internal detachable design, which reduces valve leakage points, saves valve installation space, facilitates maintenance and repair, and allows for the replacement of tension springs of different specifications according to actual needs.

[0009] In any of the above embodiments, it is preferred that the upper surface of the rocker arm contacts the lower surface of the sleeve inside the slow-closing device.

[0010] In any of the above embodiments, it is preferred that both the support shaft and the hook have small holes at their ends for placing cotter pins to secure them and prevent them from coming loose.

[0011] In any of the above embodiments, it is preferred that the hook includes a cylindrical structural member provided at the top and bottom of a rectangular plate, wherein the middle part of the upper cylinder has two grooves; the support shaft and the corresponding part of the hook also have two grooves, one end of the tension spring is fitted into the groove on the support shaft and the other end is fitted into the groove on the hook, thereby limiting the tension spring 14.

[0012] In any of the above embodiments, it is preferred that the valve disc and the rocker arm are fixedly connected by a lock nut and a washer; the rocker arm and the shift fork are connected by a cylindrical pin.

[0013] In any of the above solutions, it is preferred that the rocker arm is sleeved on the valve disc and adopts a sleeve design to reduce the friction between the rocker arm and the buffer device during the opening and closing of the valve disc, thereby increasing the service life.

[0014] In summary, the built-in slow-closing structure swing check valve of this utility model has the following advantages: the slow-closing device is set in the valve body, reducing valve leakage points and saving valve installation space; the bracket in the slow-closing device has a hollow structure, which does not affect the normal opening and closing of the valve disc; a tension spring is provided between the support shaft and the hook, and the force of the tension spring plays a buffering role when the valve disc closes, and different specifications of tension springs can be replaced according to different needs; the rocker arm is sleeved on the valve disc and adopts a sleeve design, which reduces the friction between the rocker arm and the buffer device during the opening and closing of the valve disc and increases the service life.

[0015] Explanation of icon numbers

[0016] 1. Valve body, 2. Valve disc, 3. Rocker arm, 4. Gasket, 5. Locking nut, 6. Cylindrical pin, 7. Shift fork, 8. Valve cover, 9. Metal spiral wound gasket, 10. Hex nut, 11. Socket hex screw, 12. Support shaft, 13. Bolt, 14. Tension spring, 15. Bracket, 151. U-shaped hole, 16. Hook, 161. Groove, 17. Sleeve, 18. Small hole. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a preferred embodiment of the swing check valve with built-in slow-closing structure according to the present invention.

[0018] Figure 2 In accordance with the present invention, a swing check valve with a built-in slow-closing structure is used. Figure 1 The diagram shows a schematic of the slow-closing device in the preferred embodiment.

[0019] Figure 3 In accordance with the present invention, a swing check valve with a built-in slow-closing structure is used. Figure 2 Side view of the preferred embodiment shown.

[0020] Figure 4 In accordance with the present invention, a swing check valve with a built-in slow-closing structure is used. Figure 1 The front view of the bracket in the preferred embodiment shown.

[0021] Figure 5 In accordance with the present invention, a swing check valve with a built-in slow-closing structure is used. Figure 3 Side view of the preferred embodiment shown.

[0022] Figure 6 In accordance with the present invention, a swing check valve with a built-in slow-closing structure is used. Figure 1 The diagram shows a structural schematic of the hook in the preferred embodiment. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] like Figure 1 , Figure 2 As shown, a swing check valve with a built-in slow-closing structure includes a valve body 1, a valve disc 2, a rocker arm 3, a fork 7, and a valve cover 8. The valve disc 2 is fixedly connected to the rocker arm 3. The rocker arm 3 and the fork 7 are connected by a cylindrical pin 6. The rocker arm 3 can drive the valve disc 2 to rotate. The valve body 1 is provided with a slow-closing device, which includes a support shaft 12, a bracket 15, and a hook 16. The bracket 15 has a hollow structure to facilitate the normal opening and closing of the valve disc 2. U-shaped holes 151 are opened on both sides of the bracket 15 (see...). Figure 4 , Figure 5 As shown, the support shaft 12 and hook 16 are placed in the U-shaped hole 151; a tension spring 14 is provided between the support shaft 12 and hook 16. The force of the tension spring 14 plays a buffering role when the valve disc closes, and different specifications of tension springs can be replaced according to different needs; a sleeve 17 is fitted under the hook 16. The slow-closing device is set inside the valve body 1, which reduces valve leakage points and saves valve installation space; the bracket 15 in the slow-closing device has a hollow structure and does not affect the normal opening and closing of the valve disc 2.

[0025] When the valve is in operation, when valve disc 2 changes from the open state to the closed state, valve disc 2 is subjected to its own weight and backflow pressure, as well as the force of tension spring 14, thereby achieving slow closure of valve disc 2. This prevents valve disc 2 from falling back to the closed state directly and quickly, avoiding water hammer effect and improving the service life of the valve.

[0026] The working process of the built-in slow-closing structure swing check valve of this utility model is as follows: When the valve is in the closed state, the sealing surface of the valve disc 2 and the sealing surface of the valve body 1 are in a sealed state under the action of the gravity of the valve disc 2. When there is medium flowing from the inlet end to the outlet end of the valve, the valve disc 2 is lifted under the action of the medium force. The rise of the valve disc 2 drives the rocker arm 3 to rise, and the rocker arm 3 drives the hook 16 to rise. At this time, the hook 16 in the slow-closing device makes a vertical upward movement. At this time, the hook 16 and the tension spring 14 in the support shaft 12 play an auxiliary role, and the valve opens. When there is backflow pressure or no medium flow, the valve disc 2 falls under the action of gravity. The rocker arm 3 drives the hook 16 to fall. Since the hook 16 is directly connected to the support shaft 12 by the tension spring 14, the valve disc 2 needs to overcome the spring force to slow down the closing speed of the valve disc 2 and achieve the slow-closing effect.

[0027] In this embodiment, the slow-closing structure is an internal structure, which reduces leakage points and is simple in structure and easy to install. The slow-closing device is fixedly connected to the inner wall of the valve cover 8 by hexagonal nuts 10 and bolts 13. It adopts an internal detachable design, which reduces valve leakage points, saves valve installation space, facilitates maintenance and repair, and allows for the replacement of tension springs 14 of different specifications according to actual needs.

[0028] In this embodiment, the upper surface of the rocker arm 3 is in contact with the lower surface of the sleeve 17 inside the slow-closing device.

[0029] In this embodiment, both the support shaft 12 and the hook 16 have small holes 18 at their ends for placing cotter pins to fix them in place and prevent them from falling off.

[0030] In this embodiment, the valve disc 2 and the rocker arm 3 are fixedly connected by a locking nut 5 and a washer 4; the rocker arm 3 and the shift fork 7 are connected by a cylindrical pin 6.

[0031] In this embodiment, the rocker arm 3 is sleeved on the valve disc 2 and adopts a sleeve design to reduce the friction between the rocker arm and the buffer device during the opening and closing of the valve disc, thereby increasing its service life.

[0032] See Figure 6 As shown, in the swing check valve with built-in slow-closing structure according to this utility model... Figure 1 The diagram shows a structural schematic of the hook in the preferred embodiment.

[0033] In this embodiment, the hook 16 includes a rectangular plate with a cylindrical structural member at the top and bottom. The upper cylinder has two grooves 161 in the middle. The support shaft 12 also has two grooves 161 at the corresponding part of the hook 16. One end of the tension spring 14 is fitted into the groove 161 on the support shaft 12, and the other end is fitted into the groove 161 on the hook 16, thereby limiting the tension spring 14.

[0034] Those skilled in the art will readily understand that the built-in slow-closing structure swing check valve of this utility model includes any combination of the parts described in this specification. Due to space limitations and for the sake of brevity, these combinations are not described in detail here, but after reading this specification, the scope of this utility model, which consists of any combination of the parts described in this specification, is self-evident.

Claims

1. A swing check valve with a built-in slow-closing structure, comprising a valve body (1), a valve disc (2), a rocker arm (3), a fork (7), and a valve cover (8), wherein the valve disc (2) is fixedly connected to the rocker arm (3); the rocker arm (3) and the fork (7) are connected by a cylindrical pin (6), and the rocker arm (3) can drive the valve disc (2) to rotate, characterized in that: The valve body (1) is equipped with a slow-closing device, which includes a support shaft (12), a bracket (15) and a hook (16). The bracket (15) is a hollow structure. U-shaped holes (151) are opened on both sides of the bracket (15), and the support shaft (12) and the hook (16) are placed in the U-shaped holes (151). A tension spring (14) is provided between the support shaft (12) and the hook (16). A sleeve (17) is fitted under the hook (16).

2. The swing check valve with built-in slow-closing structure as described in claim 1, characterized in that: The slow-closing structure is an internal structure; the slow-closing device is fixedly connected to the inner wall of the valve cover (8) by a hexagonal nut (10) and a bolt (13).

3. The swing check valve with built-in slow-closing structure as described in claim 1, characterized in that: The upper surface of the rocker arm (3) contacts the lower surface of the sleeve (17) inside the slow-closing device.

4. The swing check valve with built-in slow-closing structure as described in claim 1, characterized in that: Both the support shaft (12) and the hook (16) have small holes (18) at their ends.

5. The swing check valve with built-in slow-closing structure as described in claim 1, characterized in that: The hook (16) includes a rectangular plate with a cylindrical structure at the top and bottom. The upper cylindrical structure has two grooves (161) in the middle. The support shaft (12) also has two grooves (161) at the corresponding part of the hook (16). One end of the tension spring (14) is fitted into the groove (161) on the support shaft (12), and the other end is fitted into the groove (161) on the hook (16).

6. The swing check valve with built-in slow-closing structure as described in claim 1 or 4, characterized in that: The valve disc (2) and the rocker arm (3) are fixedly connected by a lock nut (5) and a washer (4); the rocker arm (3) and the shift fork (7) are connected by a cylindrical pin (6).

7. The swing check valve with built-in slow-closing structure as described in claim 1 or 5, characterized in that: The rocker arm (3) is fitted onto the valve disc (2).

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