Low resistance check valve and method of operation thereof

Abstract

The application discloses a low-resistance check valve and a working method thereof, wherein the low-resistance check valve comprises a valve seat and a valve clack, the valve clack comprises a sealing body capable of sealingly cooperating with the valve seat, a guide piece coaxially fixedly connected with the sealing body and coaxially slidingly cooperating with the valve seat and slidingly guiding the sealing body, and an elastic connecting piece connected between the guide piece and the valve seat and used for driving the sealing body to reset after being separated from the valve seat; the sealing body is a sealed shell structure with an internal hollow structure, and the valve clack is located at a position where the buoyancy of liquid in a pipeline and the gravity of the valve clack are equal. The low-resistance check valve has the advantages of simple structure, high hydraulic automatic control reliability, and the like, and the technical defects of the traditional check valve, such as large water flow resistance, low action sensitivity, poor sealing reliability, and the like, are fundamentally solved through the innovative design of core structures such as the valve clack, the valve seat and the flow passage, and the matching of light-weight and high-performance material selection, and meanwhile, the low-resistance check valve has the advantages of convenient assembly, long service life and high conveying efficiency.

Description

Technical Field

[0001] This invention relates to the field of pipeline valve technology, specifically to a low-resistance check valve and its working method. Background Technology

[0002] Check valves are core devices in pipeline systems used to prevent backflow of media. These valves typically require two to be installed in series on the pipeline. They rely on hydraulic automatic control to open and close the valve disc, and their reliability directly affects the operational safety of the pipeline system. They are widely used in municipal water supply and drinking water transportation. Existing check valves operate on the principle of automatically opening when the upstream pressure is greater than the downstream pressure and closing when the upstream pressure is less than or equal to the downstream pressure, thus preventing backflow. However, in practical applications, traditional check valves still have many technical shortcomings, making it difficult to meet the requirements of low resistance, high sensitivity, and high sealing reliability.

[0003] On the one hand, the core moving parts of traditional check valves, such as the valve disc and pressure plate, are mostly made of high-density metals such as stainless steel. The overall weight of the parts is large, and the frictional resistance between the valve stem and the center hole of the valve seat is large. This not only leads to low sensitivity of the valve to pressure changes, but also causes a significant increase in head loss when water flows through, increasing the energy consumption of the pipeline transportation system. Although some check valves have tried to use lightweight materials, they have not optimized the component structure to be lightweight, so they still cannot fundamentally reduce the moving resistance and water loss.

[0004] On the other hand, the flow channel design of traditional check valves is unreasonable. For example, the water-facing surface of the pressure plate is mostly a planar structure, and the fit between the valve disc and the flow channel has not been optimized for fluid dynamics. Turbulence and eddy currents are easily generated when water flows through, which further increases the water flow resistance and affects the pipeline's transport efficiency. At the same time, the spring force and sealing structure of some check valves are not well matched, making it difficult to ensure the sealing specific pressure required for sealing under equal pressure conditions before and after the valve. The equal pressure sealing effect is poor, and when backflow occurs, the valve disc closes slowly, which cannot quickly and reliably block the backflow of the medium. This can easily cause problems such as sewage backflow contamination of drinking water pipelines, making it difficult to meet the stringent requirements for backflow prevention.

[0005] In addition, the design of the component connection and sealing structure of traditional check valves is not perfect. The connection between moving parts and stationary parts is prone to sealing failure, which affects the overall performance and service life of the valve.

[0006] Therefore, developing a check valve with a simple structure, reliable hydraulic control, low flow resistance, high sensitivity, and high sealing reliability to solve the technical problems of existing check valves such as high water loss, low sensitivity, and poor sealing effect, and to meet the usage requirements of domestic drinking water pipelines and other backflow prevention conditions, has become an urgent technical problem to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide a check valve with simple structure, reliable hydraulic control, low water flow resistance, high action sensitivity, and high sealing reliability, as well as its working method.

[0008] To achieve this objective, the low-resistance check valve designed in this invention includes a valve seat and a valve disc. The valve disc includes a sealing body that can seal with the valve seat and a guide member that is coaxially fixedly connected to the sealing body, slidably coaxial with the valve seat, and provides sliding guidance for the sealing body. An elastic connector is connected between the guide member and the valve seat for driving the sealing body to disengage from the valve seat and then reset. The sealing body is a sealed shell structure with an internal hollow structure. The buoyancy of the liquid acting on the valve disc in the pipeline is equal to the weight of the valve disc. The guide member provides precise coaxial sliding guidance for the sealing body, preventing uneven wear of the valve disc. The elastic connector enables automatic reset of the sealing body, ensuring reliable closure. The hollow and lightweight design of the sealing body, combined with the balance of buoyancy and gravity, makes the valve disc almost suspended in the medium, significantly reducing mechanical resistance and improving the valve disc's response sensitivity to pressure changes.

[0009] Furthermore, the sealing body includes a valve core, which is a hollow hemispherical structure. One end of the guide is coaxially fixed to the center of the concave surface of the valve core, and the other end passes through the valve core and the valve seat and slides with the valve seat. The hemispherical valve core optimizes the flow channel shape, reduces water flow turbulence and eddies, and lowers water flow resistance; the hollow interior of the valve core further achieves lightweighting and enhances the balance between buoyancy and gravity; the guide is centrally connected to the valve core and slides with the valve seat, ensuring the coaxiality of the valve disc movement and making the opening and closing actions smooth and without sticking.

[0010] Furthermore, the sealing body also includes a pressure plate, which is coaxially and detachably fixed to the guide member. The pressure plate is a plate-shaped structure with a convex arc surface on the water-facing side. The valve core and the pressure plate constitute the sealing body. The pressure plate adopts a detachable design, which facilitates the assembly, maintenance, and component replacement of the sealing body. The convex arc surface on the water-facing side cooperates with the valve core to optimize the flow channel, forming a Venturi effect, further reducing water flow resistance. The valve core and the pressure plate combine to form a complete sealed shell structure, ensuring the sealing performance and structural integrity of the hollow structure of the sealing body.

[0011] Furthermore, sealing elements are fixed at the connection points between the pressure plate and the guide member, and at the connection points between the pressure plate and the valve core. The sealing element located at the connection point between the pressure plate and the valve core extends outward toward the outer side of the sealing body, forming a sealing connection structure that can mate with the valve seat. Multiple sealing elements achieve a seamless seal within the sealing body, preventing media leakage from internal gaps. The outward-extending sealing connection structure can precisely fit with the valve seat to form a surface seal, improving the sealing reliability of the mating between the sealing body and the valve seat, and structurally eliminating sealing gaps.

[0012] Furthermore, a flexible element positioning ring is coaxially disposed at the other end of the guide member. An elastic connector is connected between the elastic element positioning ring and the valve seat, and the elastic connector is coaxially sleeved on the guide member. The elastic element positioning ring provides precise axial positioning for the elastic connector, ensuring that the elastic force of the elastic connector is applied evenly along the axial direction of the guide member. The coaxial sleeved design of the elastic connector avoids uneven loading of the elastic force, ensuring uniform force distribution during valve disc reset and improving the stability and accuracy of the valve disc reset action.

[0013] Furthermore, the valve seat includes a ring-shaped sealing seat and a sleeve located in the middle of the sealing seat and coaxially slidably fitted onto the guide member. Multiple connecting rods are fixedly connected between the sleeve and the sealing seat, and these connecting rods are arranged at intervals along the circumferential direction of the sealing seat. An elastic connecting member connects the elastic positioning ring to the sleeve. The sleeve provides a dedicated sliding mating surface for the guide member, improving guiding accuracy and sliding smoothness; the circumferentially spaced connecting rods do not reduce the flow area, ensuring media flow efficiency; the combined valve seat structure, while ensuring overall structural strength, achieves functional zoning for sealing, guiding, and elastic connecting member installation, resulting in a compact and reasonable design.

[0014] Furthermore, a valve seat sealing ring mounting groove is formed on the circumferential outer surface of the sealing seat, and a valve seat sealing ring for sealing the gap between the sealing seat and the inner surface of the valve body is fixed in the valve seat sealing ring mounting groove. The valve seat sealing ring achieves a seal between the sealing seat and the valve body, preventing the medium from leaking from the gap between them, forming a secondary seal inside the valve body, and further improving the anti-backflow sealing reliability of the entire check valve.

[0015] Furthermore, the ends of the multiple connecting rods fixedly connected to the sleeve and the ends of the multiple connecting rods fixedly connected to the sealing seat are respectively located on the front and rear sides of the water-facing surface of the valve seat. The connection positions of the connecting rods prevent them from directly obstructing the forward water flow, reducing the impact of the water flow on the connecting rods and the water flow resistance, thus optimizing the hydraulic characteristics of the flow channel. At the same time, this connection method disperses the stress points of the valve seat, improving the structural stability and resistance to water flow impact, and extending the service life of the valve seat.

[0016] Furthermore, the width of the inner surface of the sealing seat gradually increases along the direction of the forward flow of the liquid in the pipeline. The gradient structure of the inner surface of the sealing seat adapts to the flow requirements after the valve disc is opened, and gradually expands the flow channel as the valve disc opening degree increases, effectively reducing the local resistance and head loss of the water flow and improving the efficiency of medium transportation.

[0017] Furthermore, a method for operating a low-resistance check valve includes a forward self-opening method and a reverse self-blocking method;

[0018] The forward self-opening method includes: the liquid in the pipeline flows forward, pushing the sealing body to separate from the valve seat, compressing the elastic connector, and allowing the liquid to pass through the gap between the sealing body and the valve seat. Automatic valve control is achieved by relying on the hydraulic pressure of the liquid in the pipeline and the elastic force of the elastic connector. It requires no external drive structure such as motors or cylinders, consumes no additional energy, has a low failure rate, and features automated and highly reliable control.

[0019] The pressure equalization self-resetting method includes: stopping the forward and reverse flow of liquid in the pipeline; ensuring that the pressure on the water-facing side of the sealing body is the same as the pressure on the water-repellent side of the sealing body; extending and resetting the elastic connector; and driving the sealing body to seal with the valve seat, thus blocking the liquid in the pipeline at the sealing connection between the sealing body and the valve seat. Under pressure equalization conditions, the automatic reset and sealing of the sealing body is achieved by the elastic force of the elastic connector, providing timely response and reliable sealing, effectively preventing minor backflow of the medium caused by pipeline pressure fluctuations, and avoiding the potential risk of medium backflow.

[0020] The reverse self-blocking method includes: the liquid in the pipeline flows in reverse, pushing the sealing body and valve seat to press tightly together and seal, while the elastic connector does not move, and the reverse-flowing liquid is blocked at the sealing connection between the sealing body and valve seat. The reverse hydraulic force pushes the sealing body and valve seat to press further together, forming a self-sealing effect. The sealing performance increases with the increase of reverse pressure, which can completely block the backflow of the medium; the elastic connector does not participate in the reverse sealing action, avoiding damage to it from the impact of reverse force and extending the service life of the elastic connector.

[0021] The beneficial effects of this invention are:

[0022] Significantly reducing water flow resistance, head loss, and energy consumption during transport: The valve disc sealing body in this invention is a hollow, sealed shell structure, ensuring that the buoyancy of the valve disc in the pipeline medium is completely equal to its own weight, making it almost suspended in the medium. Furthermore, the guide component and valve seat slide coaxially, and the use of lightweight materials reduces friction between the guide component and the valve seat sleeve to near zero, significantly reducing the mechanical resistance of the valve disc movement. Simultaneously, the pressure plate's water-facing surface is a convex arc surface, the valve core is a hemispherical structure, and the width of the inner surface of the sealing seat gradually increases along the positive flow direction of the pipeline liquid, forming a Venturi tube structure in the valve's flow channel, effectively reducing turbulence and eddies during water flow. In addition, the core components such as the valve disc, pressure plate, and valve seat are mainly made of lightweight PA66+30% glass fiber, further optimizing the hydraulic characteristics of the flow channel. Compared with traditional check valves, this significantly reduces water flow resistance and head loss, effectively saving energy in the pipeline transport system.

[0023] The valve disc exhibits high sensitivity and rapid response to pressure changes: the hollow structure of the sealing body, combined with lightweight PA66 + 30% glass fiber material, achieves a lightweight design for the valve disc. The balance between its gravity and the buoyancy of the medium allows only a small amount of positive medium pressure to overcome the pre-tightening force of the elastic connector, quickly disengaging the sealing body from the valve seat and enabling immediate valve opening. Furthermore, as the water flow rate increases, the valve disc gradually reaches the fully open position, with a smooth and unhindered opening action. Under conditions of equal pressure or backflow, the elastic force of the elastic connector meets the sealing pressure required for sealing between the valve seat and the sealing body, achieving immediate sealing under equal pressure. When backflow occurs in the pipeline, the reverse medium pressure directly pushes the sealing body and valve seat together rapidly, and combined with the restoring elastic force of the elastic connector, the valve disc closes instantly. The response speed to pressure changes before and after the valve is far superior to traditional check valves, effectively preventing the risk of medium backflow.

[0024] High sealing reliability, adaptable to stringent backflow prevention sealing requirements: This invention employs a multi-seal structure design. Seals are installed at the connections between the pressure plate and the guide, and between the pressure plate and the valve core, ensuring a strong seal within the valve core and pressure plate, eliminating internal gap leakage. Simultaneously, the seal at the connection between the pressure plate and the valve core extends outwards, forming a precise sealing connection structure that mates with the valve seat. Combined with the circumferential valve seat sealing ring, this achieves double sealing between the sealing body and the valve seat, and between the valve seat and the valve body, structurally eliminating sealing gaps. Furthermore, under reverse flow conditions, the pressure of the reverse medium in the pipeline continuously presses against the sealing surfaces of the sealing body and the valve seat, creating a self-sealing effect. At this time, the elastic connector remains stationary, and the sealing performance increases with increasing reverse pressure, effectively preventing sewage backflow and contamination of drinking water pipelines. When these valves are used in series, the reliability of the backflow prevention seal is further enhanced.

[0025] The structure is rationally designed, easy to assemble, and highly stable in operation: the guide component and the valve seat sleeve slide coaxially, providing precise coaxial guidance for the movement of the sealing body, ensuring the alignment of the valve disc with the valve seat during opening and closing, and avoiding sealing failure and increased movement resistance caused by uneven wear; the elastic connector is coaxially sleeved on the guide component, and precise positioning is achieved through the elastic component positioning ring, ensuring uniform application of the elastic force of the elastic connector and guaranteeing the stability of the valve disc reset action. The valve seat adopts a combined structure of sealing seat, connecting rod, and sleeve. Multiple connecting rods are arranged circumferentially along the sealing seat, with their ends located on the front and rear sides of the water-facing side of the valve seat, ensuring the overall structural strength of the valve seat without reducing the flow area or affecting the flow of the medium; the valve seat is fixed to the valve body by a special clamping plate, making assembly and operation convenient, and the components are manufactured as a single piece using injection molding or are detachably fixed, making later maintenance and replacement more convenient.

[0026] Optimized material and bore design ensure efficient delivery and long service life: This invention employs a material scheme combining PA66+30% glass fiber and 06Cr19Ni10 stainless steel. The lightweight and corrosion-resistant properties of PA66+30% glass fiber optimize valve resistance and adaptability to drinking water media, while the high strength of 06Cr19Ni10 stainless steel ensures the structural strength of moving parts such as guide components. Simultaneously, the check valve features a full-bore design, with its nominal diameter consistent with the core flow dimension, preventing a reduction in the flow cross-section due to the valve's structure. This effectively guarantees the flow rate and efficiency of the medium in the pipeline, adapting to pipeline systems of different diameters. Furthermore, the material selection for each component is tailored to the characteristics of drinking water media, exhibiting excellent corrosion resistance and wear resistance, effectively extending the overall service life of the valve.

[0027] With no external power drive, simple operation and maintenance, and wide applicability: This invention relies entirely on hydraulic power and the elasticity of the connecting parts to achieve automatic opening, closing, and sealing. It requires no external drive structures such as motors or cylinders, consumes no additional power during operation, and has a low failure rate. Routine maintenance only requires simple inspections to ensure performance. This valve can be widely used in various fluid transport pipelines requiring strict prevention of backflow, such as drinking water pipelines, municipal water supply systems, and water supply and drainage pipelines in civil buildings. It has excellent practical value and promising market prospects. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments disclosed in this invention, the accompanying drawings of the embodiments will be briefly described below. These drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0029] Figure 1 An axial sectional view of the internal structure of the low-resistance check valve designed in this invention;

[0030] Figure 2 This is an axial sectional view of the valve disc without the pressure plate installed in this invention;

[0031] Figure 3 This is an axial sectional view of the internal structure of the low-resistance check valve when closed in this invention.

[0032] Figure 4 This is an axial cross-sectional view of the internal structure of the low-resistance check valve when it is opened in this invention.

[0033] Figure 5 This is an axial sectional view of the internal structure of the low-resistance check valve in the counterflow condition of the present invention.

[0034] Figure 6 This is a diagram showing the key parameters of the low-resistance check valve in this invention;

[0035] Wherein, 1—valve seat (1.1—sealing seat, 1.2—connecting rod, 1.3—sleeve), 2—valve disc (2.1—sealing body, 2.2—guide element), 3—elastic connecting element, 4—valve core, 5—pressure plate, 6—elastic element positioning ring platform, 7—valve seat sealing ring mounting groove, 8—valve seat sealing ring, 9—guide rod, 10—positioning bolt, 11—guide element sealing ring mounting groove, 12—guide element sealing ring, 13—pressure plate sealing ring mounting groove, 14—pressure plate sealing ring, 15—valve core connecting rod, 16—guide rod threaded hole, 17—valve core connecting rod threaded section. Detailed Implementation

[0036] The technical solutions (including preferred technical solutions) of the present invention will be further described in detail below with reference to the accompanying drawings and by listing some optional embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0037] Example 1

[0038] like Figure 1As shown in Figure 2, this embodiment discloses a low-resistance check valve, suitable for fluid transport pipelines such as domestic drinking water pipelines and municipal water supply systems where strict prevention of backflow is required. The entire valve relies on hydraulic force and the elastic force of elastic components for automatic control, without an external drive structure. The specific structure is as follows: Figure 1 As shown in Figure 2, the valve includes valve seat 1, valve disc 2, and elastic connector 3. The materials, structures, and connections of each component are as follows:

[0039] Valve seat 1: Valve seat 1 is a modular structure, including a ring-shaped sealing seat 1.1, multiple connecting rods 1.2, and a sleeve 1.3 coaxially located in the middle of the sealing seat 1.1. The sealing seat 1.1, connecting rods 1.2, and sleeve 1.3 are all integrally molded using PA66+30% glass fiber through injection molding. Four connecting rods 1.2 are evenly spaced around the sealing seat 1.1. The two ends connecting the connecting rods 1.2 to the sleeve 1.3 and the sealing seat 1.1 are located on the front and rear sides of the water-facing surface of the valve seat 1, ensuring the structural strength of the valve seat 1 without reducing the flow area. The width of the inner surface of the sealing seat 1.1 gradually increases along the positive flow direction of the liquid in the pipeline, and its sealing surface angle ∠C is 60° (e.g., ...). Figure 6 As shown in the figure, the sealing seat 1.1 is adapted to the sealing requirements of valve disc 2; the outer circumferential surface of the sealing seat 1.1 is provided with a valve seat sealing ring mounting groove 7, in which a fluororubber valve seat sealing ring 8 is installed to achieve the sealing between the sealing seat 1.1 and the inner surface of the valve body (not shown in the figure). The sealing seat 1.1 is fixed inside the valve body by a special stainless steel clamp, which is convenient to assemble and has a firm connection; the sleeve 1.3 is a hollow tubular structure with a smooth polished inner wall, which is used to form a clearance-free sliding fit with the guide 2.2.

[0040] Valve disc 2: Valve disc 2 includes a coaxially fixed sealing body 2.1 and a guide 2.2. The sealing body 2.1 is a hollow, sealed shell structure, composed of a valve core 4 and a pressure plate 5, which are coaxially and detachably fixed. Both are injection molded using PA66+30% glass fiber. The valve core 4 is a hemispherical structure with 40% internal hollowing. The center of its concave side surface is fixedly connected to one end of the guide 2.2. The valve disc outflow angle ∠B is 85° (e.g., ...). Figure 6 As shown); the pressure plate 5 is a plate-shaped structure with a convex arc surface on the water-facing side, and its included angle ∠D on the water-facing side is 130° (as shown). Figure 6(As shown). The guide 2.2 is a solid shaft made of stainless steel 06Cr19Ni10. One end of it is fixedly connected to the sealing body 2.1, and the other end passes through the sleeve 1.3 of the sealing body 2.1 and the valve seat 1 and slides coaxially with the sleeve 1.3. The guide 2.2 includes three parts: valve core connecting rod 15, guide rod 9 and positioning bolt 10. One end of the valve core connecting rod 15 is fixedly connected to the center of the inner concave surface of the valve core 4 and is an integral structure with the valve core 4. One end of the guide rod 9 is fixed inside the valve core connecting rod 15, and the other end slides through the sleeve 1.3. The other end of the guide rod 9 is provided with a guide rod threaded hole 16. The positioning bolt 10 is threaded inside the guide rod threaded hole 16. The end face of the positioning bolt 10 near the valve disc 2 forms an elastic element positioning ring platform 6. The elastic connecting member 3 is connected between the elastic element positioning ring platform 6 and the sleeve 1.3. The end surface of the valve core connecting rod 15 near the pressure plate 5 is a threaded section 17. The middle part of the pressure plate 5 mates with the threaded section 17 of the valve core connecting rod through a threaded hole structure, and can be detachably fixed to the valve core connecting rod 15. A guide sealing ring mounting groove 11 is provided at the connection between the valve core connecting rod 15 and the pressure plate 5. A silicone guide sealing ring 12 is fitted into the groove to achieve a seal at the connection between the valve core connecting rod 15 and the pressure plate 5. A pressure plate sealing ring mounting groove 13 is provided on the annular surface of the pressure plate 5 near the valve core 4. A nitrile rubber pressure plate sealing ring 14 is fitted into the groove to achieve a seal at the connection between the two. The pressure plate sealing ring 14 extends outward from the sealing body 2.1 to form an annular sealing lip, constituting a sealing connection structure that precisely matches the sealing seat 1.1, achieving a surface seal between the sealing body 2.1 and the valve seat 1. The hollow structure of the sealing body 2.1, combined with the selection of lightweight materials, makes the overall density of the valve disc 2 the same as that of the liquid in the pipeline, such as water (1g / cm³). The buoyancy of the valve disc 2 in the pipeline liquid is exactly equal to its own weight, and it is almost suspended in the medium.

[0041] Elastic connector 3: The elastic connector 3 is made of stainless steel compression spring, which is coaxially sleeved on the guide 2.2. One end of the spring abuts against the end face of the elastic positioning ring 6, and the other end abuts against the end face of the sleeve 1.3 of the valve seat 1. The preload of the spring is precisely calculated to meet the sealing pressure required for the sealing body 2.1 and the valve seat 1 to seal and ensure the sealing effect of the valve disc 2 under flat pressure conditions.

[0042] Key nozzle parameters: such as Figure 6 As shown, the check valve in this embodiment adopts a full-bore design, with its nominal diameter φA consistent with the nominal diameter of the pipeline, without any reduction in the flow cross section, ensuring the efficiency of medium transportation; the sliding mating surfaces of the guide 2.2 and the sleeve 1.3 are mirror-finished, and combined with the floating design of the valve disc 2, the frictional resistance between the two is almost zero.

[0043] The low-resistance check valve in this embodiment can be installed in series on the pipeline system in two ways, according to the actual pipeline operating conditions, to further improve the reliability of the anti-backflow sealing.

[0044] Example 2

[0045] This embodiment discloses a working method for the low-resistance check valve described in Embodiment 1. This method relies on the hydraulic pressure of the liquid within the pipeline and the elastic force of the elastic connector 3 to achieve forward self-opening, pressure equalization self-resetting, and reverse self-blocking of the check valve. No external power intervention is required throughout the process, and the control process is automated and highly reliable. Specifically, it includes three parts: a forward self-opening method, a pressure equalization self-resetting method, and a reverse self-blocking method. The specific operation process of each method is as follows:

[0046] like Figure 3 As shown in Figure 4, the forward self-opening method is as follows: When the liquid in the pipeline flows in the forward direction, the pressure of the medium before the valve is greater than that after the valve. The forward hydraulic pressure acts directly on the water-facing surface of the pressure plate 5 of the sealing body 2.1, forming a thrust in the direction after the valve. After overcoming the pre-tightening force of the elastic connector 3, the thrust pushes the sealing body 2.1 to move in the direction after the valve along the axial direction of the guide 2.2, so that the sealing body 2.1 quickly separates from the sealing seat 1.1 of the valve seat 1. The elastic connector 3 is compressed as the sealing body 2.1 moves. The liquid passes through the annular gap between the sealing body 2.1 and the sealing seat 1.1. As the water flow velocity in the pipeline continues to increase, the forward hydraulic thrust on the sealing body 2.1 gradually increases, and the opening of the valve disc 2 gradually increases synchronously until the sealing body 2.1 moves to the limit position, and the check valve reaches the fully open position and the opening no longer changes. At this time, the liquid flows smoothly along the Venturi tube-shaped flow channel, and the water flow resistance and head loss are minimized.

[0047] Self-resetting method under equal pressure: When the liquid in the pipeline stops flowing in both the forward and reverse directions, and the pressure of the medium before and after the valve tends to be balanced (equal pressure condition), the positive hydraulic thrust on the sealing body 2.1 disappears, the compressed elastic connector 3 releases its elastic potential energy and extends to reset, and its elastic force pushes the guide 2.2 to move axially towards the valve front along the sleeve 1.3, thereby driving the sealing body 2.1 to reset synchronously until the annular sealing lip on the outside of the sealing body 2.1 is tightly fitted with the sealing seat 1.1 of the valve seat 1; the pre-tightening force of the elastic connector 3 ensures that the sealing surface reaches the required sealing pressure, realizing the reliable sealing of the check valve under equal pressure condition and preventing the slight backflow of the medium caused by pressure fluctuation.

[0048] like Figure 5As shown, the reverse self-blocking method works as follows: When the medium flows backward in the pipeline due to reasons such as increased pipeline pressure at the user end or decreased municipal water supply pressure, the pressure of the medium after the valve is greater than that before the valve. The reverse hydraulic pressure acts directly on the convex surface of the valve core 4 of the sealing body 2.1, forming a pressure in the direction of the valve, which pushes the sealing body 2.1 and the sealing seat 1.1 of the valve seat 1 to press and fit together further, forming a self-sealing effect. At this time, the elastic connector 3 has no extension or retraction movement, and its pre-tightening force is superimposed with the reverse hydraulic pressure, so that the sealing specific pressure of the sealing surface increases with the increase of the reverse pressure, and the sealing reliability is enhanced simultaneously. The reverse-flowing medium is completely blocked at the sealing connection between the sealing body 2.1 and the sealing seat 1.1, realizing the complete blocking of the backflow of the medium and effectively preventing the backflow of sewage from polluting the drinking water pipeline.

[0049] In the working method of this embodiment, the valve disc 2 has no additional mechanical resistance during its movement due to the suspension design that balances buoyancy and gravity. It responds to pressure changes before and after the valve very quickly, and there is no sluggishness in the opening, resetting and closing actions. Moreover, there is no wear on any parts during the entire working process, which can effectively extend the overall service life of the check valve.

[0050] In summary, the low-resistance check valve designed in this invention has a simple structure and high reliability of hydraulic automatic control. Through innovative design of core structures such as valve disc 2, valve seat 1, and flow channel, coupled with lightweight and high-performance material selection, it fundamentally solves the technical defects of traditional check valves such as high water flow resistance, low action sensitivity, and poor sealing reliability. At the same time, it also has the advantages of convenient assembly, long service life, and high conveying efficiency.

[0051] It should be noted that the above description of the technical solutions is exemplary, and this specification may be embodied in different forms and should not be construed as limiting it to the technical solutions set forth herein. Rather, providing these descriptions will ensure that the disclosure of this invention is thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Furthermore, the technical solutions of this invention are defined only by the scope of the claims.

[0052] The shapes, dimensions, ratios, angles, and figures disclosed in the description of various aspects of this specification and claims are merely examples, and therefore, this specification and claims are not limited to the details shown. In the following description, detailed descriptions of relevant known functions or configurations will be omitted where it would be determined that they unnecessarily obscure the focus of this specification and claims.

[0053] When using the terms “comprising,” “having,” and “including” as described in this specification, there may also be another part or other parts, and the terms used are generally singular but may also be plural.

[0054] It should be noted that although the terms "first," "second," "top," "bottom," "one side," "the other side," "one end," "the other end," etc., may appear and be used in this specification to describe various components, these components and parts should not be limited by these terms. These terms are only used to distinguish one component and part from another. For example, without departing from the scope of this specification, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component; top and bottom components may, under certain circumstances, be interchanged or converted; components at one end and at the other end may have the same or different performance characteristics.

[0055] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention should be considered within the protection scope of the present invention.

Claims

1. A low-resistance check valve, comprising a valve seat (1) and a valve disc (2), characterized in that: The valve disc (2) includes a sealing body (2.1) that can seal with the valve seat (1) and a guide member (2.2) that is coaxially fixedly connected to the sealing body (2.1), slidably connected to the valve seat (1), and slides to guide the sealing body (2.1). An elastic connector (3) is connected between the guide member (2.2) and the valve seat (1) for driving the sealing body (2.1) to disengage from the valve seat (1) and then reset. The sealing body (2.1) is a sealed shell structure with an internal hollow structure. The buoyancy of the liquid on the valve disc (2) in the pipeline is equal to the weight of the valve disc (2).

2. The low-resistance check valve as described in claim 1, characterized in that: The sealing body (2.1) includes a valve core (4), which is a hollow hemispherical structure. One end of the guide (2.2) is coaxially fixedly connected to the center of the concave side surface of the valve core (4), and the other end passes through the valve core (4) and the valve seat (1) and slides with the valve seat (1).

3. The low-resistance check valve as described in claim 2, characterized in that: The sealing body (2.1) also includes a pressure plate (5), which is coaxially and detachably fixed to the guide (2.2). The pressure plate (5) is a plate-shaped structure with a convex arc surface on the water-facing side. The valve core (4) and the pressure plate (5) constitute the sealing body (2.1).

4. The low-resistance check valve as described in claim 3, characterized in that: Sealing elements are fixed at the connection between the pressure plate (5) and the guide (2.2) and at the connection between the pressure plate (5) and the valve core (4). The sealing element located at the connection between the pressure plate (5) and the valve core (4) extends toward the outside of the sealing body (2.1) to form a sealing connection structure that can cooperate with the valve seat (1).

5. The low-resistance check valve as described in claim 4, characterized in that: The other end of the guide (2.2) is coaxially provided with an elastic element positioning ring platform (6), and the elastic element positioning ring platform (6) is connected to the valve seat (1) by the elastic connector (3), and the elastic connector (3) is coaxially sleeved on the guide (2.2).

6. The low-resistance check valve as described in claim 5, characterized in that: The valve seat (1) includes a ring-shaped sealing seat (1.1) and a sleeve (1.3) located in the middle of the sealing seat (1.1) and coaxially slidably sleeved on the guide member (2.2). Multiple connecting rods (1.2) are fixedly connected between the sleeve (1.3) and the sealing seat (1.1). The multiple connecting rods (1.2) are arranged at intervals along the circumferential direction of the sealing seat (1.1). The elastic member positioning ring (6) is connected to the sleeve (1.3) by the elastic connecting member (3).

7. The low-resistance check valve as described in claim 6, characterized in that: The outer circumferential surface of the sealing seat (1.1) is provided with a valve seat sealing ring mounting groove (7), and a valve seat sealing ring (8) for sealing the gap between the sealing seat (1.1) and the inner surface of the valve body is fixed in the valve seat sealing ring mounting groove (7).

8. The low-resistance check valve as described in claim 6, characterized in that: One end of the multiple connecting rods (1.2) fixedly connected to the sleeve (1.3) and the other end of the multiple connecting rods (1.2) fixedly connected to the sealing seat (1.1) are respectively located on the front and rear sides of the water-facing surface of the valve seat (1).

9. The low-resistance check valve as described in claim 6, characterized in that: The width of the inner surface of the sealing seat (1.1) gradually increases along the direction of the positive flow of liquid in the pipeline.

10. A method for operating a low-resistance check valve as described in any one of claims 1-9: characterized in that: It includes the forward self-opening method, the flat pressure self-reset method, and the reverse self-blocking method; The forward self-opening method includes: the liquid in the pipeline flows forward, pushing the sealing body (2.1) to separate from the valve seat (1), the elastic connector (3) is compressed, and the liquid passes through the gap between the sealing body (2.1) and the valve seat (1); The pressure equalization self-reset method includes: the liquid in the pipeline stops flowing in both the forward and reverse directions, the pressure on the water-facing side of the sealing body (2.1) is the same as the pressure on the back side of the sealing body (2.1), the elastic connector (3) extends and resets, driving the sealing body (2.1) to seal with the valve seat (1), and the liquid in the pipeline is blocked at the sealing connection between the sealing body (2.1) and the valve seat (1); The reverse self-blocking method includes: the liquid in the pipeline flows in reverse, pushing the sealing body (2.1) and the valve seat (1) to press and seal, the elastic connector (3) does not move, and the reverse-flowing liquid is blocked at the sealing connection between the sealing body (2.1) and the valve seat (1).

Images