A non-return stop valve

Abstract

The utility model relates to a check stop valve, including the valve body, the valve body is equipped with the import and export, and the medium flows from the import to the export, the valve body inside is equipped with the stop component and check component, the stop component includes the adjusting rod and stop piston, the adjusting rod rotates and is installed in the upper portion of valve body, can drive the stop piston along the axial movement through rotating the adjusting rod, the check component includes the pressure relief piston, guide rod and return spring, the pressure relief piston is fixedly connected with the guide rod through the fastening nut and forms a whole movable piece, the return spring acts on the whole movable piece, provides the pre -tightening force for it to the closing direction, the guide rod penetrates the stop piston and with its sliding fit, through having adopted the integration structure of stop piston and pressure relief piston, has realized two kinds of functions of reliable cut -off of stop valve and reverse check of check valve simultaneously in a valve body, simple structure has reduced the complexity and weight of pipeline system, especially suitable for the occasion of space limited.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, specifically a check valve. Background Technology

[0002] In fluid transport pipeline systems, such as water supply and drainage, fire protection, HVAC, and industrial processes, a valve is typically required that can both manually shut off the flow and prevent backflow. The traditional approach involves installing a separate shut-off valve and a separate check valve in series on the pipeline.

[0003] While this separate combination offers complete functionality, it has significant drawbacks: First, it requires a large installation space, making deployment difficult in space-constrained environments; second, the connection between the two valves via pipe fittings increases potential leakage points, raising installation complexity and maintenance costs; and finally, the procurement and installation of two independent valves also contributes to higher overall costs.

[0004] To overcome these shortcomings, "stop check valves" integrating both functions have emerged on the market. However, existing integrated valves often have complex structures, require significant opening and closing forces, or their check function cannot achieve a completely reliable shut-off seal when maintenance is needed, posing a risk of internal leakage. In addition, the guiding structure of many existing valves is not stable enough, and after long-term use, they are prone to shaking due to media impact, affecting the lifespan and sealing performance of the sealing pair, and their regulating performance is also relatively limited. Utility Model Content

[0005] The purpose of this invention is to provide a check valve to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A check valve includes a valve body having an inlet and an outlet, wherein a medium flows from the inlet to the outlet; the valve body is internally provided with a shut-off component and a check component. The shut-off assembly includes an adjusting rod and a shut-off piston. The adjusting rod is rotatably mounted on the upper part of the valve body, and the shut-off piston can be driven to move axially by rotating the adjusting rod. The check valve assembly includes a pressure-reducing piston, a guide rod, and a return spring. The pressure-reducing piston is fixedly connected to the guide rod by a fastening nut to form an integral movable part. The return spring acts on the integral movable part to provide it with a preload force in the closing direction. The guide rod passes through the stop piston and slides with it.

[0007] When the medium flows from the inlet to the outlet, if the shut-off piston opens, the medium pressure overcomes the preload of the return spring and pushes the pressure-reducing piston to open, thus opening the flow channel. When the pressure on the inlet side disappears or the pressure on the outlet side is higher than that on the inlet side, the return spring pushes the pressure-reducing piston to close, preventing the medium from flowing in the opposite direction.

[0008] Optionally, the head of the adjusting rod has an axial groove, and a screw is provided on the stop piston. The end of the screw extends into the axial groove, so that the rotational movement of the adjusting rod can be converted into the axial movement of the stop piston. The adjusting rod and the stop piston are connected by a first fastening nut.

[0009] Optionally, a first sealing ring is provided at the lower end of the shut-off piston, and the first sealing ring forms a sealing fit with the upper valve port in the valve body. That is, when the shut-off piston moves downward, the first sealing ring and the upper valve port on the valve body form a sealing pair.

[0010] Optionally, a second sealing ring is provided at the upper end of the pressure reducing piston, and the second sealing ring forms a sealing fit with the lower valve port in the valve body.

[0011] Optionally, the pressure-reducing piston is connected to the second fastening nut via a thread, and the guide rod is fixedly connected to the second fastening nut, so that the pressure-reducing piston, the second fastening nut and the guide rod form a rigid linkage.

[0012] Optionally, the upper end of the adjusting rod passes through a pressure cap disposed on the valve body.

[0013] Compared with the prior art, the beneficial effects of this utility model are: 1. By adopting an integrated structure of the shut-off piston and the pressure-reducing piston, the two functions of reliable shut-off valve and reverse check valve are realized simultaneously in one valve body. The structure is simple, reducing the complexity and weight of the pipeline system, and is particularly suitable for space-constrained occasions.

[0014] 2. By physically separating and coordinating the actuators for the "stop" and "check" functions, the stop function is precisely controlled manually, while the check function is automatically triggered by a spring and differential pressure. This ensures that when the valve is used as a check valve, even if the upper stop function is open, the lower check function remains independently effective, providing dual safety protection and preventing system backflow accidents due to misoperation or failure of a single component. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0016] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description is provided in conjunction with the accompanying drawings and preferred embodiments, based on the specific implementation methods, structure, features and effects of this utility model.

[0017] like Figure 1 As shown, a check valve includes a valve body 3, which has an inlet A and an outlet B, through which the medium flows from the inlet A to the outlet B; the valve body 3 is internally provided with a shut-off component and a check component. The shut-off assembly includes an adjusting rod 6 and a shut-off piston 1. The adjusting rod 6 is rotatably mounted on the upper part of the valve body 3. By rotating the adjusting rod 6, the shut-off piston 1 can be driven to move axially. The check valve assembly includes a pressure reducing piston 2, a guide rod 5, and a return spring 4. The pressure reducing piston 2 is fixedly connected to the guide rod 5 via a second fastening nut 9 to form an integral movable part. The return spring 4 acts on the integral movable part to provide it with a preload force in the closing direction. The guide rod 5 passes through the shut-off piston 1 and slides with it. When the medium flows from inlet A to outlet B, if the shut-off piston 1 opens, the medium pressure overcomes the preload of the return spring 4 and pushes the pressure reducing piston 2 to open, thus opening the flow channel. When the pressure on the inlet A side disappears or the pressure on the outlet B side is higher than that on the inlet A side, the return spring 4 pushes the pressure reducing piston 2 to close, preventing the medium from flowing in the opposite direction.

[0018] The adjusting rod 6 has an axial groove at its head, and a screw 7 is mounted on the stop piston 1. The end of the screw 7 extends into the axial groove, so that the rotational movement of the adjusting rod 6 can be converted into the axial movement of the stop piston 1. The adjusting rod 6 and the stop piston 1 are connected by a first fastening nut 8.

[0019] The lower end of the shut-off piston 1 is provided with a first sealing ring 10, which forms a sealing fit with the upper valve port 12 inside the valve body 3. That is, when the shut-off piston 1 moves downward, the first sealing ring 10 and the upper valve port 12 on the valve body 3 form a sealing pair. The upper end of the pressure reducing piston 2 is provided with a second sealing ring 11, which forms a sealing fit with the lower valve port 13 inside the valve body 3. The pressure reducing piston 2 and the second fastening nut 9 are connected by threads, and the guide rod 5 is fixedly connected to the second fastening nut 9, so that the pressure reducing piston 2, the second fastening nut 9 and the guide rod 5 constitute a rigid linkage. The upper end of the adjusting rod 6 passes through the pressure cap 14 provided on the valve body 3.

[0020] The working process of this utility model is described below: 1. In the closed state, rotate the adjusting rod on the upper part of the valve cover clockwise. The adjusting rod rotates downward and pushes the shut-off piston to move downward along the axis through the engagement of the groove at its head and the screw.

[0021] When the piston is pressed down, the first sealing ring at its bottom is pressed tightly against the valve seat sealing surface of the valve body, forming a strong sealing pair. At this point, the flow path from the inlet to the outlet is completely blocked.

[0022] At this point, the present invention functions as a standard shut-off valve, providing reliable manual shut-off for easy system maintenance or isolation. Under the action of the lower return spring, the pressure-reducing piston also has the second sealing ring in close contact with the lower valve port, forming a sealing pair, and the entire valve is in the closed position.

[0023] 2. Rotate the adjusting rod counterclockwise. The adjusting rod moves upward, pulling the shut-off piston upward through the slotted screw structure, opening the upper valve port. After the shut-off piston rises, the medium pressure from inlet A acts on the lower end face of the pressure-reducing piston. When the medium pressure exceeds the preload of the return spring, the pressure will push the entire pressure-reducing piston, the second fastening nut, and the guide rod downward together to compress the spring, thereby opening the lower valve port. At this point, the flow path is completely unobstructed, and the medium flows smoothly from A to B.

[0024] 3. When the pressure source (such as a water pump) on the inlet A side stops and the pressure on the outlet B side is higher than that on the inlet A side, the pressure on the A side disappears, and the thrust acting on the lower end of the pressure reducing piston decreases sharply.

[0025] At this moment, the preload of the return spring is quickly released, pushing the pressure-reducing piston back to its original position. The second sealing ring at the upper end of the pressure-reducing piston fits tightly against the lower valve port, forming an effective seal and effectively blocking the reverse flow of the medium from B to A, thus acting as a check valve.

[0026] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A check valve, comprising a valve body having an inlet and an outlet, wherein a medium flows from the inlet to the outlet; characterized in that, The valve body is equipped with a shut-off component and a check-back component; The shut-off assembly includes an adjusting rod and a shut-off piston. The adjusting rod is rotatably mounted on the upper part of the valve body, and the shut-off piston can be driven to move axially by rotating the adjusting rod. The check valve assembly includes a pressure-reducing piston, a guide rod, and a return spring. The pressure-reducing piston is fixedly connected to the guide rod by a fastening nut to form an integral movable part. The return spring acts on the integral movable part to provide it with a preload force in the closing direction. The guide rod passes through the stop piston and slides with it.

2. The check valve according to claim 1, characterized in that, The head of the adjusting rod is provided with an axial groove, and a screw is provided on the stop piston. The end of the screw extends into the axial groove, so that the rotational movement of the adjusting rod can be converted into the axial movement of the stop piston. The adjusting rod is connected to the stop piston by a first fastening nut.

3. A check valve according to claim 1, characterized in that, The lower end of the stop piston is provided with a first sealing ring, which forms a sealing fit with the upper valve port in the valve body.

4. A check valve according to claim 3, characterized in that, The upper end of the pressure reducing piston is provided with a second sealing ring, which forms a sealing fit with the lower valve port in the valve body.

5. A check valve according to claim 1, characterized in that, The pressure-reducing piston is connected to the second fastening nut by a thread, and the guide rod is fixedly connected to the second fastening nut, so that the pressure-reducing piston, the second fastening nut and the guide rod form a rigid linkage.

6. A check valve according to claim 1, characterized in that, The upper end of the adjusting rod passes through the pressure cap set on the valve body.

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