Backflow-preventing water-saving pressure-reducing device

Abstract

The utility model provides an anti-backflow water-saving pressure reducing device which comprises a connector body and a pressure reducing assembly, the connector body comprises an inlet connector and an outlet connector, and the first end of the inlet connector is detachably connected with the first end of the outlet connector. The second end of the inlet connector and the second end of the outlet connector are both detachably connected with a pipeline port, the pressure reducing assembly is connected with one of the inlet connector and the outlet connector, the pressure reducing assembly is arranged in a cavity of the connector body and comprises a pressure reducing film, and the connector body has a pressure reducing state and a backflow preventing state. The cross section area of the pressure reduction film is increased along with the rise of water pressure in the inlet connector, a gap is formed between the pressure reduction film and the wall face of the cavity of the connector body, and at least part of the pressure reduction film abuts against the wall face of the cavity of the connector body in the backflow prevention state so as to block communication between the inlet connector and the outlet connector. The anti-backflow water-saving pressure reducing device has the advantages of being simple in structure and convenient to disassemble and assemble.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to an anti-backflow water-saving and pressure-reducing device. Background Art

[0002] In the related art, special pressure reducing devices or pressure reducing valve groups require a large installation space and many accessories or parts, and the accessories cannot be replaced individually. When the water supply end is connected to a separate sanitary appliance and needs to be reduced in pressure, or when the renovation project requires no valve group or device installation space, special pressure reducing devices or pressure reducing valve groups cannot be used. In addition, the special pressure reducing device or pressure reducing valve group system is complex and expensive. When damaged, local accessories cannot be replaced, and the pressure reducing valve or pressure reducing device needs to be replaced as a whole. The inspection and replacement are complicated and require professional personnel to operate. Utility Model Content

[0003] The utility model aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the embodiment of the utility model provides an anti-backflow water-saving and pressure-reducing device, which has the advantages of simple structure and convenient assembly and disassembly.

[0004] The anti-backflow water-saving and pressure-reducing device of the utility model embodiment comprises:

[0005] A joint body, the joint body comprising an inlet joint and an outlet joint, the first end of the inlet joint is detachably connected to the first end of the outlet joint, the second end of the inlet joint and the second end of the outlet joint are both detachably connected to the pipeline port, and the extension direction of the joint body is consistent with the up-down direction;

[0006] A decompression assembly, the decompression assembly is connected to one of the inlet joint and the outlet joint, and the decompression assembly is placed in the cavity of the joint body, the decompression assembly includes a decompression membrane,

[0007] The joint body has a decompression state and an anti-backflow state. In the decompression state, the cross-sectional area of ​​the decompression membrane increases with the increase of the water pressure in the inlet joint, and there is a gap between the decompression membrane and the wall surface of the cavity of the joint body;

[0008] In the backflow prevention state, at least a portion of the pressure reducing membrane abuts against the wall surface of the cavity of the joint body to block the communication between the inlet joint and the outlet joint.

[0009] The anti-backflow water-saving and pressure-reducing device of the embodiment of the utility model connects the connected inlet joint and outlet joint to the pipe port. When the water pressure in the pipe gradually increases, the pressure-reducing membrane gradually increases its own volume under the action of the water pressure to gradually occupy the cavity of the joint body, so that the flow area of ​​the joint body is reduced, thereby realizing the throttling function. In addition, when the water supply in the pipe is stopped, the water in the pipe will flow back into the main pipe. The pressure-reducing membrane contacts the inner wall of the inlet joint under the action of the water flow to form a sealing structure, thereby realizing the anti-backflow function.

[0010] In some embodiments, the pressure reducing assembly further comprises a fixed grid, which is annular in shape, whose outer peripheral wall is connected to one of the inlet joint and the outlet joint, and whose pressure reducing membrane is connected to the inner peripheral wall of the fixed grid.

[0011] In some embodiments, the pressure reducing assembly further comprises a sealing ring, wherein the sealing ring is connected to the fixed grid, and the sealing ring abuts against at least one of the inlet joint and the outlet joint.

[0012] In some embodiments, the inlet joint includes a first connecting section, a first reducing section, and a second connecting section connected in sequence, the first connecting section is connected to the lower end of the outlet joint, the second connecting section is connected to the pipeline port, the first reducing section has a protrusion at one end adjacent to the first connecting section, the protrusion extends toward the cavity of the inlet joint, and the sealing ring abuts against the protrusion.

[0013] In some embodiments, the first connecting section is threadably connected to the outlet connector, and the lower end of the outlet connector is placed in a cavity of the first connecting section.

[0014] In some embodiments, the cross-sectional area of ​​the first reducing section gradually decreases in a direction from top to bottom.

[0015] In some embodiments, the outlet connector includes a third connecting segment, a second reducing segment and a fourth connecting segment connected in sequence, the third connecting segment is connected to the first connecting segment, and the cross-sectional area of ​​the second reducing segment gradually decreases in a top-to-bottom direction.

[0016] In some embodiments, the pressure relief membrane is made of rubber material. In the pressure relief state, the pressure relief membrane is placed in the cavity of the outlet joint. In the anti-backflow state, the pressure relief membrane is placed in the inlet joint and contacts the cavity wall of the inlet joint.

[0017] In some embodiments, the inlet connector and the outlet connector are both transparent connectors.

[0018] In some embodiments, the anti-backflow water-saving and pressure-reducing device of the utility model embodiment further includes a first coating and a second coating, wherein the first coating is disposed on the upper surface of the pressure-reducing membrane, and the second coating is disposed on the lower surface of the pressure-reducing membrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the anti-backflow water-saving and pressure-reducing device (pressure-reducing state) of an embodiment of the utility model.

[0020] Figure 2 It is a structural schematic diagram of the backflow prevention water-saving and pressure-reducing device of an embodiment of the utility model.

[0021] Figure 3 It is a structural schematic diagram of the anti-backflow water-saving and pressure-reducing device (anti-backflow state) of an embodiment of the utility model.

[0022] Figure 4 yes Figure 1 An enlarged schematic diagram of A is shown in FIG.

[0023] Figure 5 It is a structural schematic diagram of a fixed grid of a backflow prevention water-saving and pressure-reducing device according to an embodiment of the utility model.

[0024] Reference numerals:

[0025] 1. Connector body, 11. Inlet connector, 111. First connecting section, 112. First reducing section, 1121. Protrusion, 113. Second connecting section, 12. Outlet connector, 121. Third connecting section, 122. Second reducing section, 123. Fourth connecting section,

[0026] 2. Pressure reducing assembly, 21. Pressure reducing membrane, 211. First coating, 212. Second coating, 22. Fixed grid, 23. Sealing ring,

[0027] 100, normal pressure membrane position, 200, first overpressure membrane position, 300, second overpressure membrane position. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention.

[0029] like Figure 1-Figure 5 As shown, the anti-backflow water-saving and pressure-reducing device of the embodiment of the utility model comprises a joint body 1 and a pressure-reducing assembly 2 .

[0030] The connector body 1 includes an inlet connector 11 and an outlet connector 12, wherein the first end of the inlet connector 11 is detachably connected to the first end of the outlet connector 12, the second end of the inlet connector 11 and the second end of the outlet connector 12 are both detachably connected to the pipeline port, and the extension direction of the connector body 1 is consistent with the up-down direction. The decompression assembly 2 is connected to one of the inlet connector 11 and the outlet connector 12, and the decompression assembly 2 is placed in the cavity of the connector body 1, and the decompression assembly 2 includes a decompression membrane 21, and the connector body 1 has a decompression state and an anti-backflow state. In the decompression state, the cross-sectional area of ​​the decompression membrane 21 increases with the increase of the water pressure in the inlet connector 11, and there is a gap between the decompression membrane 21 and the wall surface of the cavity of the connector body 1. In the anti-backflow state, at least part of the decompression membrane 21 abuts against the wall surface of the cavity of the connector body 1 to block the connection between the inlet connector 11 and the outlet connector 12.

[0031] Specifically, Figure 1-Figure 4 As shown, the inlet joint 11 is located below the outlet joint 12, and the upper end of the inlet joint 11 and the lower end of the outlet joint 12 can be connected by threaded connection, flange connection, etc., which is convenient for disassembly and assembly. The decompression assembly 2 can be connected to the inlet joint 11 and located at the top position of the inlet joint 11; or, the decompression assembly 2 can be connected to the outlet joint 12 and located at the lower end position of the inlet joint 11, so as to facilitate the replacement and installation of the decompression assembly 2. In addition, there is a water gap between the decompression membrane 21 and the cavity wall of the joint body 1, so that the water source can flow in the cavity of the joint body 1.

[0032] It is understandable that when the water pressure in the inlet joint 11 increases (water flows from bottom to top), the pressure relief membrane 21 gradually increases its cross-sectional area under the pressure of the water flow, that is, the area of ​​the cavity of the joint body 1 occupied by the pressure relief membrane 21 gradually increases, resulting in a decrease in the flow area of ​​the water flowing through the pressure relief membrane 21 and an increase in the head loss, thereby achieving a pressure relief effect. When the cross-sectional area of ​​the pressure relief membrane 21 increases to a certain extent, and a gap is ensured between the pressure relief membrane 21 and the wall of the cavity of the joint body 1, water can pass through while maintaining the pressure relief effect.

[0033] After the water supply in the pipeline stops, the water in the pipeline will flow back into the main pipe of the pipeline, that is, as shown in the figure, the water above the pressure-reducing membrane 21 flows from top to bottom and acts on the pressure-reducing membrane 21, causing the pressure-reducing membrane 21 to expand toward the inlet joint 11 until the pressure-reducing membrane 21 contacts the cavity wall of the inlet joint 11 to form a sealing structure, thereby preventing water backflow and ensuring water quality safety.

[0034] In other words, the anti-backflow water-saving and pressure-reducing device of the embodiment of the utility model connects the connected inlet joint 11 and outlet joint 12 to the pipe port. When the water pressure in the pipe gradually increases, the pressure-reducing membrane 21 gradually increases its own volume under the action of the water pressure to gradually occupy the cavity of the joint body 1, so that the flow area of ​​the joint body 1 is reduced, thereby realizing the throttling function. In addition, when the water supply in the pipe is stopped, the water in the pipe will flow back into the main pipe. The pressure-reducing membrane 21 contacts the inner wall of the inlet joint 11 under the action of the water flow to form a sealing structure, thereby realizing the anti-backflow function.

[0035] Therefore, the anti-backflow water-saving and pressure-reducing device of the embodiment of the utility model can meet the pressure-reducing requirements of the water supply system, and has the advantages of simple structure, reliable effect, low maintenance cost, etc. In the renovation project of the water supply system, the device can be easily installed and used without special technology and professional knowledge, thereby reducing the installation and maintenance costs.

[0036] In some embodiments, the decompression assembly 2 further includes a fixed grid 22 which is annular in shape, an outer peripheral wall of the fixed grid 22 is connected to one of the inlet connector 11 and the outlet connector 12 , and the decompression membrane 21 is connected to an inner peripheral wall of the fixed grid 22 .

[0037] Specifically, Figure 1 and Figure 5 As shown, the outer peripheral wall of the fixed grid 22 is connected to the outer peripheral wall of the inlet joint 11. Preferably, the outer contour of the fixed grid 22 is adapted to the contour of the cavity of the inlet joint 11 so that the fixed grid 22 can be snapped into the inlet joint 11 to avoid movement under the action of water flow.

[0038] It is understandable that if Figure 5 As shown, the middle of the fixed grid 22 is hollow to facilitate the edge of the pressure reducing membrane 21 to be connected to the inner wall surface of the fixed grid 22 , and water can flow in the joint body 1 through the pores on the fixed grid 22 .

[0039] In some embodiments, the decompression assembly 2 further includes a sealing ring 23 , which is connected to the fixed grid 22 , and the sealing ring 23 abuts against at least one of the inlet connector 11 and the outlet connector 12 .

[0040] Specifically, Figure 1 and Figure 4 As shown, the sealing ring 23 is located below the fixed grid 22, and the sealing ring 23 is arranged near the edge of the fixed grid 22. When the inlet joint 11 and the outlet joint 12 are installed, the sealing ring 23 can be used to block the gap between the fixed grid 22 and the inner wall of the inlet joint 11 to avoid water leakage and ensure the stability of the water flow.

[0041] Preferably, the sealing ring 23 is made of rubber material so that the sealing ring 23 can be deformed when squeezed, so that the sealing ring 23 can better seal the edge gap of the fixed grid 22 to improve the sealing performance.

[0042] In some embodiments, the inlet connector 11 includes a first connecting section 111, a first reducing section 112, and a second connecting section 113 connected in sequence, the first connecting section 111 is connected to the lower end of the outlet connector 12, the second connecting section 113 is connected to the pipeline port, the first reducing section 112 has a protrusion 1121 at one end adjacent to the first connecting section 111, the protrusion 1121 extends toward the cavity of the inlet connector 11, and the sealing ring 23 abuts against the protrusion 1121.

[0043] Specifically, Figure 1-Figure 3 As shown, the inner diameter of the first reducing section 112 is smaller than the inner diameter of the first connecting section 111, the protrusion 1121 is annular and located at the upper end of the first reducing section 112, and the fixed grid 22 can be placed on the protrusion 1121 to facilitate the installation and replacement of the fixed grid 22. The sealing ring 23 is located between the protrusion 1121 and the fixed grid 22, and when the fixed grid is subjected to pressure, the sealing ring 23 can be squeezed to improve the sealing effect after the sealing ring 23 is deformed.

[0044] Optionally, the first connection section 111 is threadedly connected to the outlet joint 12, and the lower end of the outlet joint 12 is placed in the cavity of the first connection section 111. As shown in the figure, the upper end of the first connection section 111 is provided with an internal thread, and the lower end of the outlet joint 12 is provided with an external thread, so that the first connection section 111 and the outlet joint 12 can be threadedly connected. The lower end of the outlet joint 12 is threadedly connected to the first connection section 111, and the lower end of the outlet joint 12 can abut against the fixed grid 22, so that the fixed grid 22 can be fixed.

[0045] Preferably, in the direction from top to bottom, the cross-sectional area of ​​the first reducing section 112 gradually decreases. Figure 1 As shown, the radial dimension of the first reducing section 112 gradually decreases from top to bottom so that the connector body 1 is in an anti-backflow state (i.e., the water flows downward), and the pressure reducing membrane 21 extends from the outlet connector 12 to the inlet connector 11 under the action of the gravity of the water flow, and part of the water flow can be gathered in the space surrounded by the pressure reducing membrane 21 until the wall surface of the pressure reducing membrane 21 contacts the inner wall surface of the first reducing section 112, thereby forming a sealing structure with an anti-backflow function.

[0046] In some embodiments, the outlet connector 12 includes a third connecting segment 21, a second reducing segment 122 and a fourth connecting segment 123 connected in sequence, the third connecting segment 21 is connected to the first connecting segment 111, and the cross-sectional area of ​​the second reducing segment 122 gradually decreases from top to bottom.

[0047] It is understandable that if Figure 1 and Figure 2 As shown, when the water flows into the connector body 1, it passes through the second connecting section 113, the first reducing section 112, the first connecting section 111, the third connecting section 21, the second reducing section 122 and the fourth connecting section 123 in sequence. Among them, the water flows from the second connecting section 113 to the first reducing section 112, and the water flow velocity decreases due to the increase in the pipe diameter, and enters the third connecting section 21 after passing through the fixed grid 22. It should be noted that since the water flow velocity decreases before passing through the fixed grid 22, the water flow can be evenly distributed on the fixed grid 22, and since the filtration area of ​​the fixed grid 22 is equal to the flow area of ​​the third connecting section 21, the water flow remains stable.

[0048] Since the water flows from bottom to top, the pressure reducing membrane 21 can occupy a certain flow space in the outlet joint 12 (i.e., above the fixed grid 22) under the action of the water flow, so the water flow through the fixed grid 22 is faster than the water flow in the inlet joint 11. And the water flows through the third connecting section 21 to the second reducing section 122. Since the pipe diameter of the second reducing section 122 gradually decreases, the flow rate of the water passing through gradually increases until the water flows to the fourth connecting section 123 and the water flow rate is restored.

[0049] That is to say, the arrangement of the first reducing diameter section 112 and the second reducing diameter section 122 makes the water flow more stable, thereby reducing the local head loss of the water flow in the joint body 1 .

[0050] In addition, it should be noted that the second connection section 113 and the fourth connection section 123 can be connected to the pipeline port in different connection modes, such as threaded connection, flange connection, etc. It is understandable that when the pipeline ports are all hard plastic pipes, the second connection section 113 and the fourth connection section 123 can be connected to the pipeline end in a flange connection. When there is a hose at the pipeline port, the second connection section 113 and the fourth connection section 123 can be connected to the pipeline port in a threaded connection, so that it can be applied to different scenarios.

[0051] In some embodiments, the pressure relief membrane 21 is made of rubber material. In the pressure relief state, the pressure relief membrane 21 is placed in the cavity of the outlet joint 12. In the anti-backflow state, the pressure relief membrane 21 is placed in the inlet joint 11 and contacts the cavity wall of the inlet joint 11.

[0052] It is understandable that if Figure 1 and Figure 2As shown, under the impact of water flow (water flows from bottom to top), the pressure reducing membrane 21 forms a "sphere"-like structure, so that the pressure reducing membrane 21 can occupy part of the space of the outlet joint 12, and when the water flow pressure in the inlet joint 11 increases, the pressure reducing membrane 21 will expand, so that its own volume will increase, further increasing the occupied space and ensuring the stability of the water flow.

[0053] like Figure 2 As shown, it should be noted that the inventor found that when the water inlet pressure is 0.15MPa, the rubber membrane is in the normal pressure membrane position 100 (i.e., no expansion occurs), when the water inlet pressure is 0.25MPa, the rubber membrane is in the first overpressure membrane position 200, and when the water inlet pressure is 0.35MPa, the rubber membrane is in the second overpressure membrane position 300. When the rubber membrane is in three different membrane positions, it is tested that the pressure behind the membrane is 0.15-0.2MPa, which meets the standard water-saving and pressure-reducing requirements. Therefore, the anti-backflow water-saving and pressure-reducing device of the embodiment of the utility model has the advantage of good pressure-reducing effect.

[0054] Preferably, both the inlet connector 11 and the outlet connector 12 are transparent connectors. It is understandable that, since the pressure reducing membrane 21 undergoes corresponding changes in different states, the inlet connector 11 and the outlet connector 12 are both made of transparent plastic material, so that the state of the pressure reducing membrane 21 can be observed intuitively, so as to ensure that any problems with the pressure reducing membrane 21 can be discovered in time and then quickly replaced.

[0055] In some embodiments, the anti-backflow water-saving and pressure-reducing device of the utility model embodiment further includes a first coating 211 and a second coating 212 , wherein the first coating 211 is disposed on the upper surface of the pressure-reducing membrane 21 , and the second coating 212 is disposed on the lower surface of the pressure-reducing membrane 21 .

[0056] It can be understood that the first coating 211 and the second coating 212 are two color coatings, for example, the first coating 211 is a red coating, and the second coating 212 is a blue coating, then, when the joint body 1 is in the throttling state, the pressure relief membrane 21 can show the red coating, and when the joint body 1 is in the anti-backflow state, the pressure relief membrane 21 can show the blue coating. Thus, the user can directly observe the working state of the rubber membrane through the transparent joint and judge whether it needs to be repaired or replaced.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0058] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0059] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0061] In the present utility model, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0062] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are illustrative and cannot be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A backflow prevention water-saving and pressure-reducing device, characterized in that: include: A joint body, the joint body comprising an inlet joint and an outlet joint, the first end of the inlet joint is detachably connected to the first end of the outlet joint, the second end of the inlet joint and the second end of the outlet joint are both detachably connected to the pipeline port, and the extension direction of the joint body is consistent with the up-down direction; A decompression assembly, the decompression assembly is connected to one of the inlet joint and the outlet joint, and the decompression assembly is placed in the cavity of the joint body, the decompression assembly includes a decompression membrane, The joint body has a decompression state and an anti-backflow state. In the decompression state, the cross-sectional area of ​​the decompression membrane increases with the increase of the water pressure in the inlet joint, and there is a gap between the decompression membrane and the wall surface of the cavity of the joint body; In the backflow prevention state, at least a portion of the pressure reducing membrane abuts against the wall surface of the cavity of the joint body to block the communication between the inlet joint and the outlet joint.

2. The anti-backflow water-saving and pressure-reducing device according to claim 1, characterized in that: The decompression assembly further comprises a fixed grid which is annular in shape, an outer peripheral wall of which is connected to one of the inlet joint and the outlet joint, and the decompression membrane is connected to an inner peripheral wall of the fixed grid.

3. The anti-backflow water-saving and pressure-reducing device according to claim 2, characterized in that: The pressure reducing assembly further comprises a sealing ring, wherein the sealing ring is connected to the fixed grid and abuts against at least one of the inlet joint and the outlet joint.

4. The anti-backflow water-saving and pressure-reducing device according to claim 3, characterized in that: The inlet joint includes a first connecting section, a first reducing section and a second connecting section which are connected in sequence, the first connecting section is connected to the lower end of the outlet joint, the second connecting section is connected to the pipeline port, the first reducing section has a protrusion at one end adjacent to the first connecting section, the protrusion extends toward the cavity of the inlet joint, and the sealing ring abuts against the protrusion.

5. The anti-backflow water-saving and pressure-reducing device according to claim 4, characterized in that: The first connecting section is threadably connected to the outlet joint, and the lower end of the outlet joint is placed in the cavity of the first connecting section.

6. The backflow prevention water-saving and pressure-reducing device according to claim 5, characterized in that: In the direction from top to bottom, the cross-sectional area of ​​the first reducing diameter section gradually decreases.

7. The anti-backflow water-saving and pressure-reducing device according to claim 6, characterized in that: The outlet joint comprises a third connecting section, a second reducing section and a fourth connecting section which are connected in sequence. The third connecting section is connected to the first connecting section. In a direction from top to bottom, the cross-sectional area of ​​the second reducing section gradually decreases.

8. The anti-backflow water-saving and pressure-reducing device according to any one of claims 1 to 7, characterized in that: The pressure relief membrane is made of rubber material. In the pressure relief state, the pressure relief membrane is placed in the cavity of the outlet joint. In the backflow prevention state, the pressure relief membrane is placed in the inlet joint and contacts the cavity wall of the inlet joint.

9. The anti-backflow water-saving and pressure-reducing device according to claim 8, characterized in that: The inlet joint and the outlet joint are both transparent joints.

10. The backflow prevention water-saving and pressure-reducing device according to claim 9, characterized in that: It also includes a first coating layer and a second coating layer, wherein the first coating layer is disposed on the upper surface of the pressure reducing film, and the second coating layer is disposed on the lower surface of the pressure reducing film.

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