Pressure difference regulating valve with emergency shut-off and anti-backflow function

Abstract

The present application relates to the technical field of valve body, propose a kind of differential pressure regulating valve with emergency shut-off and anti-backflow function, including main valve body, main valve membrane and valve core assembly, main valve body includes the valve cavity with water inlet end and water outlet end, main valve membrane is arranged in valve cavity and divides valve cavity into control chamber and overflow chamber, further include anti-backflow reversing valve, reset reversing valve, shut-off reversing valve and differential pressure pilot valve, make differential pressure regulating valve be in differential pressure dynamic regulation state, when differential pressure regulating valve is in differential pressure dynamic regulation state, shut-off reversing valve transposition to close differential pressure pilot valve and water outlet end communication, make differential pressure regulating valve switch to emergency shut-off state and thus close, when differential pressure regulating valve is in differential pressure dynamic regulation state, anti-backflow reversing valve transposition to close water inlet end and control chamber communication and make water outlet end and control chamber communication, make differential pressure regulating valve switch to anti-backflow state and thus close.The problems that downstream leakage or backflow cannot be blocked in time in conventional differential pressure regulating valve in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of valve body technology, specifically to a differential pressure regulating valve with emergency shut-off and anti-backflow functions. Background Technology

[0002] Differential pressure regulating valves generally refer to self-operated differential pressure control valves. Self-operated differential pressure control valves do not require external energy and rely on the pressure changes of the controlled medium itself for automatic adjustment. They automatically eliminate residual pressure head in the pipeline network and flow deviations caused by pressure fluctuations, maintaining a constant pressure difference between the user's inlet and outlet, which helps stabilize system operation.

[0003] Despite significant advancements in differential pressure regulating valve technology, several challenges remain in practical applications. For instance, traditional differential pressure regulating valves continue to supply water even when dealing with large-scale drainage in response to downstream emergencies, leading to substantial water waste. Furthermore, they lack a function to prevent backflow due to increased downstream pressure, especially in situations where downstream contamination is a possibility. Therefore, a valve body capable of addressing these issues is urgently needed. Summary of the Invention

[0004] This invention proposes a differential pressure regulating valve with emergency shutdown and backflow prevention functions, which solves the problem that traditional differential pressure regulating valves in the prior art cannot promptly block downstream leakage or backflow.

[0005] The technical solution of the present invention is as follows:

[0006] A differential pressure regulating valve with emergency shutdown and anti-backflow functions is disclosed. The differential pressure regulating valve includes a main valve body, a main valve diaphragm, and a valve core assembly. The main valve body includes a valve cavity with an inlet end and an outlet end. The main valve diaphragm is disposed in the valve cavity and divides the valve cavity into a control cavity and a flow cavity. The valve core assembly is connected to the main valve diaphragm. The deformation of the main valve diaphragm controls the valve core assembly to open or close the flow cavity. The differential pressure regulating valve also includes an anti-backflow reversing valve, a reset reversing valve, a shut-off reversing valve, and a differential pressure pilot valve. The inlet end, the anti-backflow reversing valve, the control cavity, the differential pressure pilot valve, the shut-off reversing valve, and the outlet end are sequentially connected, and the inlet end and the differential pressure pilot valve are connected to enable the differential pressure regulating valve to be in a differential pressure dynamic regulation state.

[0007] When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the shut-off reversing valve switches to close the differential pressure pilot valve and the outlet end, so that the differential pressure regulating valve switches to the emergency shut-off state and is thus closed.

[0008] When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow reversing valve switches to close the inlet end and the control chamber and connect the outlet end and the control chamber, so that the differential pressure regulating valve switches to the anti-backflow state and is closed.

[0009] When the differential pressure regulating valve is closed, the reset directional valve is switched to connect the control chamber, the reset directional valve, the shut-off directional valve and the outlet, so that the differential pressure regulating valve enters the open state.

[0010] The anti-backflow directional valve includes an anti-backflow port one, an anti-backflow port two, and an anti-backflow port three. The differential pressure pilot valve includes a pilot valve port one, a pilot valve port two, and a pilot valve port three. The shut-off directional valve includes a shut-off port one and a shut-off port two. The differential pressure pilot valve includes a pilot valve body, a pilot valve diaphragm, a preload spring, and a pilot valve core. The pilot valve diaphragm divides the pilot valve body into a sensing chamber and a communicating chamber. The pilot valve core is connected to the pilot valve diaphragm. The preload spring is sleeved on the portion of the pilot valve core located within the sensing chamber. The pilot valve port one communicates with the sensing chamber. Both pilot valve port 2 and pilot valve port 3 are connected to the communication cavity. When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow port 1 is connected to the water inlet. The anti-backflow reversing valve connects the anti-backflow port 2 and the anti-backflow port 3 according to the pressure of the anti-backflow port 1. The water inlet, the anti-backflow port 2, the anti-backflow port 3, the control cavity, the pilot valve port 2, the pilot valve port 3, the shut-off port 1, the shut-off port 2, and the water outlet can be connected in sequence. The pilot valve port 1 is connected to the water inlet.

[0011] The shut-off reversing valve also includes a shut-off port three, which is connected to the water outlet. The shut-off reversing valve selectively connects or shuts off the shut-off port one and the shut-off port two according to the pressure of the shut-off port three.

[0012] The anti-backflow reversing valve also includes an anti-backflow port four and an anti-backflow port five. The anti-backflow port four is connected to the water outlet. The anti-backflow reversing valve selectively connects or shuts off the anti-backflow port three and the anti-backflow port five according to the pressure of the anti-backflow port four. The anti-backflow port five is connected to the water outlet.

[0013] The reset reversing valve further includes a reset port one, a reset port two, and a reset port three. The shut-off reversing valve further includes a shut-off port four. The reset reversing valve also includes a reset button. The reset port three is connected to the water outlet. The reset reversing valve can close the reset port one and the reset port two according to the pressure of the reset port three. The reset button can open the reset port one and the reset port two. The shut-off reversing valve can selectively open or close the shut-off port four and the shut-off port two according to the pressure of the shut-off port three.

[0014] The anti-backflow reversing valve, the reset reversing valve, and the shut-off reversing valve all include a reversing valve body and a reversing valve core, and the reversing valve core moves within the reversing valve body to switch the connection state.

[0015] The valve core assembly includes a valve stem and a valve plate. The valve stem is connected to the main valve diaphragm, and the valve plate is disposed in the portion of the valve stem located within the flow cavity.

[0016] The differential pressure regulating valve also includes a regulating needle valve, and the anti-backflow reversing valve is connected to the control chamber via the regulating needle valve.

[0017] The working principle and beneficial effects of this invention are as follows:

[0018] This invention discloses a differential pressure regulating valve with emergency shutdown and anti-backflow functions. The valve structure has a valve chamber within the main valve body, with an inlet and an outlet. A main valve diaphragm is installed within the valve chamber, dividing it into a control chamber and a flow chamber. The main valve diaphragm is connected to a valve core assembly. The main valve diaphragm controls the valve core assembly based on the pressure deformation within the control chamber, and the valve core assembly controls the flow in the flow chamber. The main valve body also includes an anti-backflow directional valve, a reset directional valve, a shut-off directional valve, and a differential pressure pilot valve. By controlling different connection schemes between the valve bodies, the differential pressure regulating valve can be in different states to handle different scenarios. When the differential pressure regulating valve is opened, due to the pressure at the inlet and outlet... When the water pressure changes, the connection status of each auxiliary valve changes. Firstly, when the inlet and outlet are in normal operating condition, the differential pressure pilot valve dynamically adjusts according to the pressure difference between the inlet and outlet, keeping the pressure difference within a preset range. Secondly, if a pipe bursts at the outlet, causing a surge in drainage, the shut-off directional valve changes the connection status, quickly closing and entering an emergency shut-off state. Thirdly, if the outlet pressure suddenly increases due to a fault, the anti-backflow directional valve activates, and the differential pressure regulating valve switches from dynamic adjustment to anti-backflow mode, quickly closing. This solution addresses the problem of downstream leakage or backflow that cannot be promptly blocked in traditional differential pressure regulating valves. Attached Figure Description

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 This is a schematic diagram of the differential pressure regulating valve in its initial state according to the present invention;

[0021] Figure 2 This is a schematic diagram of the differential pressure regulating valve in the open water inlet state of the present invention;

[0022] Figure 3 This is a schematic diagram of the differential pressure regulating valve's dynamic differential pressure adjustment state structure according to the present invention;

[0023] Figure 4This is a schematic diagram of the differential pressure regulating valve in the emergency shut-off state of the present invention;

[0024] Figure 5 This is a schematic diagram of the differential pressure regulating valve in the pressure anti-backflow shut-off state of the present invention;

[0025] In the diagram: 1. Main valve body; 2. Main valve diaphragm; 3. Inlet; 4. Outlet; 5. Control chamber; 6. Flow chamber; 7. Anti-backflow directional valve; 8. Reset directional valve; 9. Shut-off directional valve; 10. Differential pressure pilot valve; 11. Anti-backflow port one; 12. Anti-backflow port two; 13. Anti-backflow port three; 14. Anti-backflow port four; 15. Anti-backflow port five; 16. Pilot valve port one; 17. Pilot valve port two; 18. 19. Pilot valve port 3; 20. Shut-off port 1; 21. Shut-off port 2; 22. Shut-off port 3; 23. Shut-off port 4; 24. Pilot valve body; 25. Pilot valve diaphragm; 26. Preload spring; 27. Pilot valve core; 28. Sensing chamber; 29. ​​Communicating chamber; 30. Reset port 1; 31. Reset port 2; 32. Reset button; 33. Valve stem; 34. Valve plate; 35. Adjusting needle valve. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] like Figures 1-5 As shown, this embodiment proposes a differential pressure regulating valve with emergency shut-off and anti-backflow functions. The differential pressure regulating valve includes a main valve body 1, a main valve diaphragm 2, and a valve core assembly. The main valve body 1 includes a valve cavity with an inlet end 3 and an outlet end 4. The main valve diaphragm 2 is disposed in the valve cavity and divides the valve cavity into a control cavity 5 and a flow cavity 6. The valve core assembly is connected to the main valve diaphragm 2. The deformation of the main valve diaphragm 2 controls the valve core assembly to open or close the flow cavity 6. The differential pressure regulating valve also includes an anti-backflow reversing valve 7, a reset reversing valve 8, a shut-off reversing valve 9, and a differential pressure pilot valve 10. The inlet end 3, the anti-backflow reversing valve 7, the control cavity 5, the differential pressure pilot valve 10, the shut-off reversing valve 9, and the outlet end 4 are sequentially connected, and the inlet end 3 and the differential pressure pilot valve 10 are connected to enable the differential pressure regulating valve to be in a differential pressure dynamic regulation state.

[0028] When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the shut-off reversing valve 9 switches to close the differential pressure pilot valve 10 and the outlet end 4, so that the differential pressure regulating valve switches to the emergency shut-off state and is thus closed.

[0029] When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow reversing valve 7 switches to close the inlet end 3 and the control chamber 5 and connects the outlet end 4 and the control chamber 5, so that the differential pressure regulating valve switches to the anti-backflow state and is closed.

[0030] When the differential pressure regulating valve is closed, the reset reversing valve 8 is switched to connect the control chamber 5, the reset reversing valve 8, the shut-off reversing valve 9, and the outlet 4, so that the differential pressure regulating valve enters the open state.

[0031] This embodiment discloses a differential pressure regulating valve with emergency shut-off and anti-backflow functions. The differential pressure regulating valve has a valve cavity inside the main valve body 1, which has an inlet end 3 and an outlet end 4. A main valve diaphragm 2 is installed inside the valve cavity, dividing the valve cavity into a control cavity 5 and a flow cavity 6. The main valve diaphragm 2 is connected to a valve core assembly. The main valve diaphragm 2 controls the valve core assembly according to the pressure deformation in the control cavity 5. The valve core assembly controls the on / off state in the flow cavity 6. The main valve body 1 is also equipped with an anti-backflow reversing valve 7, a reset reversing valve 8, a shut-off reversing valve 9, and a differential pressure pilot valve 10. By controlling different connection schemes between the valve bodies, the differential pressure regulating valve can be in different states to respond to different situations. In the scenario where the differential pressure regulating valve is opened, the pressure changes at the inlet 3 and outlet 4, causing the auxiliary valves to change their connection status. First, when the inlet 3 and outlet 4 are in normal working condition, the differential pressure pilot valve 10 dynamically adjusts according to the pressure difference between the inlet 3 and outlet 4, keeping the pressure difference between the inlet 3 and outlet 4 within a preset pressure range. When a pipe bursts at outlet 4, causing a surge in drainage, the shut-off reversing valve 9 changes the connection status, thus quickly closing and entering the emergency shut-off state. When the outlet 4 experiences a sudden increase in pressure due to a fault, the anti-backflow reversing valve 7 activates, and the differential pressure regulating valve changes from the dynamic adjustment state to the anti-backflow state, quickly closing.

[0032] It should be noted that the multiple auxiliary valves set up based on the technical concept of this application to achieve the functions of dynamic differential pressure regulation, emergency shutdown and backflow prevention, that is, adjusting the connection status of each auxiliary valve according to the pressure change at the inlet end 3 and the outlet end 4, if it is just a simple change in the valve body structure, quantity and connection method, it should fall within the protection scope of this application.

[0033] The anti-backflow directional valve 7 includes an anti-backflow port 11, an anti-backflow port 22, and an anti-backflow port 33. The differential pressure pilot valve 10 includes a pilot valve port 16, a pilot valve port 27, and a pilot valve port 38. The shut-off directional valve 9 includes a shut-off port 19 and a shut-off port 20. The differential pressure pilot valve 10 includes a pilot valve body 23, a pilot valve diaphragm 24, a preload spring 25, and a pilot valve core 26. The pilot valve diaphragm 24 divides the pilot valve body 23 into a sensing chamber 27 and a communicating chamber 28. The pilot valve core 26 is connected to the pilot valve diaphragm 24. The preload spring 25 is sleeved on the portion of the pilot valve core 26 located within the sensing chamber 27. The pilot valve port 16 is connected to the pilot valve diaphragm 24. The sensing chamber 27 is connected, and both the second pilot valve port 17 and the third pilot valve port 18 are connected to the connecting chamber 28. When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the first anti-backflow port 11 is connected to the inlet end 3. The anti-backflow reversing valve 7 connects the second anti-backflow port 12 and the third anti-backflow port 13 according to the pressure of the first anti-backflow port 11. The inlet end 3, the second anti-backflow port 12, the third anti-backflow port 13, the control chamber 5, the second pilot valve port 17, the third pilot valve port 18, the first shut-off port 19, the second shut-off port 20, and the outlet end 4 can be connected in sequence. The first pilot valve port 16 is connected to the inlet end 3.

[0034] In this embodiment, the differential pressure regulating valve is open and the inlet end 3 and outlet end 4 are in normal operating condition. The differential pressure pilot valve 10 can sense the pressure difference between the inlet end 3 and outlet end 4. The differential pressure pilot valve 10 can set a certain pressure difference by abutting the pilot valve core 26 through the pre-tightening spring 25. When the pressure difference between the inlet end 3 and outlet end 4 is greater than the preset value, the pilot valve diaphragm 24 deforms, causing the pilot valve core 26 to open the pilot valve port 2 17 and the pilot valve port 3 18. The water pressure in the control chamber 5 flows to the outlet end 4 through the pilot valve port 2 17, the pilot valve port 3 18, the shut-off port 1 19, and the shut-off port 2 20, thereby reducing the water pressure in the control chamber 5. The opening of the differential pressure regulating valve increases, thereby increasing the pressure at the outlet end 4. When the pressure difference between the inlet end 3 and the outlet end 4 decreases to within the preset pressure difference range, when the pressure difference between the inlet end 3 and the outlet end 4 is less than the preset value, the diaphragm 24 of the differential pressure pilot valve 10 deforms upward, the differential pressure pilot valve 10 moves towards closing, the water flow in the control chamber 5 decreases, the pressure rises, the opening of the differential pressure regulating valve decreases, the inlet end 3 reduces the water supply to the outlet end 4, thereby gradually reducing the pressure at the outlet end 4, and the pressure difference between the inlet end 3 and the outlet end 4 gradually approaches the preset value; when the pressure difference between the inlet end 3 and the outlet end 4 equals the preset value, the differential pressure pilot valve 10 closes, the pressure in the control chamber 5 rises, the differential pressure regulating valve closes, and the pressure difference between the inlet end 3 and the outlet end 4 remains at the preset value.

[0035] The shut-off reversing valve 9 also includes a shut-off port three 21, which is connected to the water outlet 4. The shut-off reversing valve 9 selectively connects or shuts off the shut-off port one 19 and the shut-off port two 20 according to the pressure of the shut-off port three 21.

[0036] In this embodiment, when the differential pressure regulating valve is in the differential pressure dynamic adjustment state, if a pipe bursts at the outlet 4, the water flow rate at the outlet 4 increases, and the water flow at the inlet 3 also increases. Due to the increased water flow, the water velocity accelerates, and the high-speed water flow has a water flow ejection principle, thereby reducing the water pressure at the shut-off port 21 to a very low level, or even to zero pressure. The shut-off reversing valve 9 adjusts the connection state according to the pressure at the shut-off port 21, shutting off the shut-off port 19 and shut-off port 20. The water in the control chamber 5 cannot be diverted to the outlet 4, and the pressure in the control chamber 5 increases rapidly, thereby causing the flow chamber 6 of the differential pressure regulating valve to close quickly, realizing the emergency shut-off function and avoiding water waste.

[0037] The anti-backflow reversing valve 7 also includes an anti-backflow port four 14 and an anti-backflow port five 15. The anti-backflow port four 14 is connected to the water outlet 4. The anti-backflow reversing valve 7 selectively connects or shuts off the anti-backflow port three 13 and the anti-backflow port five 15 according to the pressure of the anti-backflow port four 14. The anti-backflow port five 15 is connected to the water outlet 4.

[0038] In this embodiment, when the pressure at the outlet 4 suddenly increases, the anti-backflow port 14 of the anti-backflow reversing valve 7 senses the high pressure at the outlet 4. The anti-backflow reversing valve 7 then adjusts the connection state, closing the anti-backflow port 12 and the anti-backflow port 13, and connecting the anti-backflow port 13 to the anti-backflow port 15. The anti-backflow port 15 is connected to the outlet 4, and the high pressure at the outlet 4 enters the control chamber 5 through the anti-backflow port 15 and the anti-backflow port 13. The pressure in the control chamber 5 increases instantaneously, causing the differential pressure regulating valve to close quickly and preventing backflow.

[0039] The reset reversing valve 8 further includes a reset port 1 29, a reset port 2 30, and a reset port 31. The shut-off reversing valve 9 further includes a shut-off port 4 22. The reset reversing valve 8 also includes a reset button 32. The reset port 31 is connected to the water outlet 4. The reset reversing valve 8 can close the reset port 1 29 and the reset port 2 30 according to the pressure of the reset port 3 31. The reset button 32 can open the reset port 1 29 and the reset port 2 30. The shut-off reversing valve 9 can selectively open or close the shut-off port 4 22 and the shut-off port 2 20 according to the pressure of the shut-off port 3 21.

[0040] In this embodiment, when the differential pressure regulating valve is in the closed state, it needs to be initially opened. This is achieved by changing the connection state of the reset directional valve 8, which slowly opens the differential pressure regulating valve. Specifically, the pressure at the inlet 3 is higher than the pressure at the outlet 4. The anti-backflow directional valve 7 is connected between anti-backflow port 12 and anti-backflow port 13. The pressure at the inlet 3 enters the control chamber 5 through anti-backflow port 12 and anti-backflow port 13. The pressure then flows from the control chamber 5 to the reset port 29 and reset port 30 of the reset directional valve 8, and finally to the shut-off port 22. The pressure at the shut-off port 21 of the shut-off directional valve 9 is low, and the shut-off port 22 is connected to the shut-off port 20. The pressure output from the reset directional valve 8 enters the outlet 4 through the shut-off port 22 and shut-off port 20. Due to the reduced pressure in the control chamber 5, the pressure at the inlet 3 is applied to the valve core assembly, which is greater than the pressure applied to the main valve diaphragm 2 by the control chamber 5. The flow chamber 6 of the differential pressure regulating valve slowly opens, and the pressure at the outlet 4 gradually increases. The increased pressure at the outlet 4 applies pressure to the reset port 31 of the reset directional valve 8 and the shut-off port 21 of the shut-off directional valve 9, thereby changing the connection state of the reset directional valve 8 and the shut-off directional valve 9. The reset port 29 and reset port 30 of the reset directional valve 8 are closed, and the shut-off port 22 and shut-off port 20 of the shut-off directional valve 9 are closed. The shut-off port 19 and shut-off port 20 are connected, thereby connecting the outlet 4 to the pilot port 18 of the differential pressure pilot valve 10. The differential pressure regulating valve enters the differential pressure dynamic adjustment state from the initial open state.

[0041] The anti-backflow reversing valve 7, the reset reversing valve 8, and the shut-off reversing valve 9 all include a reversing valve body and a reversing valve core. The reversing valve core moves within the reversing valve body to switch the connection state.

[0042] In this embodiment, the anti-backflow reversing valve 7, the reset reversing valve 8, and the shut-off reversing valve 9 all adopt a structure in which a reversing valve core is set inside the reversing valve body. The reversing valve core can be moved by the medium pressure, spring force, or external pressing force to adjust the connection state and realize different working states of the differential pressure regulating valve.

[0043] The valve core assembly includes a valve stem 33 and a valve plate 34. The valve stem 33 is connected to the main valve diaphragm 2, and the valve plate 34 is disposed in the portion of the valve stem 33 located within the flow cavity 6.

[0044] In this embodiment, the valve core assembly consists of a valve stem 33 and a valve plate 34. The valve cover is connected to the main valve diaphragm 2. A guide structure that cooperates with the valve stem 33 is provided in the main valve body 1 so that the deformation of the main valve diaphragm 2 can drive the valve stem 33 to move. The end of the valve stem 33 is provided with a valve plate 34. The valve plate 34 can abut against and seal with the flow channel structure in the flow cavity 6 to realize the closure and opening of the flow channel.

[0045] The differential pressure regulating valve also includes a regulating needle valve 35, and the anti-backflow reversing valve 7 is connected to the control chamber 5 via the regulating needle valve 35.

[0046] In this embodiment, the anti-backflow reversing valve 7 is connected to the control chamber 5 through the regulating needle valve 35. The regulating needle valve 35 consists of a needle valve body and a needle valve core. Rotating the needle valve core can adjust the opening of the regulating needle valve 35 and control the flow rate of the diverted flow.

[0047] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A differential pressure regulating valve with emergency shutdown and backflow prevention functions, characterized in that, The differential pressure regulating valve includes a main valve body (1), a main valve diaphragm (2), and a valve core assembly. The main valve body (1) includes a valve cavity with an inlet end (3) and an outlet end (4). The main valve diaphragm (2) is disposed in the valve cavity and divides the valve cavity into a control cavity (5) and a flow cavity (6). The valve core assembly is connected to the main valve diaphragm (2). The main valve diaphragm (2) deforms to control the valve core assembly to open or close the flow cavity (6). The differential pressure regulating valve also includes an anti-backflow reversing valve (7), a reset reversing valve (8), a shut-off reversing valve (9), and a differential pressure pilot valve (10). The inlet end (3), the anti-backflow reversing valve (7), the control cavity (5), the differential pressure pilot valve (10), the shut-off reversing valve (9), and the outlet end (4) are connected in sequence, and the inlet end (3) and the differential pressure pilot valve (10) are connected to make the differential pressure regulating valve in a differential pressure dynamic regulation state. When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the shut-off reversing valve (9) switches to close the differential pressure pilot valve (10) and the outlet (4), so that the differential pressure regulating valve switches to the emergency shut-off state and is closed. When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow reversing valve (7) switches to close the inlet end (3) and the control chamber (5) and connect the outlet end (4) and the control chamber (5) so that the differential pressure regulating valve switches to the anti-backflow state and closes. When the differential pressure regulating valve is closed, the reset reversing valve (8) switches to connect the control chamber (5), the reset reversing valve (8), the shut-off reversing valve (9), and the outlet (4) so ​​that the differential pressure regulating valve enters the open state. The anti-backflow reversing valve (7) includes an anti-backflow port one (11), an anti-backflow port two (12), and an anti-backflow port three (13). The differential pressure pilot valve (10) includes a pilot valve port one (16), a pilot valve port two (17), and a pilot valve port three (18). The shut-off reversing valve (9) includes a shut-off port one (19) and a shut-off port two (20). The differential pressure pilot valve (10) includes a pilot valve body (23), a pilot valve diaphragm (24), a preload spring (25), and a pilot valve core (26). The pilot valve diaphragm (24) divides the pilot valve body (23) into a sensing chamber (27) and a communicating chamber (28). The pilot valve core (26) is connected to the pilot valve diaphragm (24). The preload spring (25) is sleeved on the portion of the pilot valve core (26) located in the sensing chamber (27). The pilot valve port one (11) 6) The valve is connected to the sensing chamber (27). The pilot valve port 2 (17) and the pilot valve port 3 (18) are both connected to the connecting chamber (28). When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow port 1 (11) is connected to the water inlet (3). The anti-backflow reversing valve (7) connects the anti-backflow port 2 (12) and the anti-backflow port 3 (13) according to the pressure of the anti-backflow port 1 (11). The water inlet (3), the anti-backflow port 2 (12), the anti-backflow port 3 (13), the control chamber (5), the pilot valve port 2 (17), the pilot valve port 3 (18), the shut-off port 1 (19), the shut-off port 2 (20) and the water outlet (4) can be connected in sequence. The pilot valve port 1 (16) is connected to the water inlet (3).

2. The differential pressure regulating valve with emergency shut-off and anti-backflow functions according to claim 1, characterized in that, The shut-off reversing valve (9) also includes a shut-off port three (21), which is connected to the water outlet (4). The shut-off reversing valve (9) selectively connects or shuts off the shut-off port one (19) and the shut-off port two (20) according to the pressure of the shut-off port three (21).

3. The differential pressure regulating valve with emergency shut-off and anti-backflow function according to claim 1 or 2, characterized in that, The anti-backflow reversing valve (7) also includes an anti-backflow port four (14) and an anti-backflow port five (15). The anti-backflow port four (14) is connected to the water outlet (4). The anti-backflow reversing valve (7) selectively connects or shuts off the anti-backflow port three (13) and the anti-backflow port five (15) according to the pressure of the anti-backflow port four (14). The anti-backflow port five (15) is connected to the water outlet (4).

4. The differential pressure regulating valve with emergency shutdown and anti-backflow function according to claim 3, characterized in that, The reset reversing valve (8) further includes a reset port one (29), a reset port two (30), and a reset port three (31). The shut-off reversing valve (9) further includes a shut-off port four (22). The reset reversing valve (8) further includes a reset button (32). The reset port three (31) is connected to the water outlet (4). The reset reversing valve (8) can close the reset port one (29) and the reset port two (30) according to the pressure of the reset port three (31). The reset button (32) can open the reset port one (29) and the reset port two (30). The shut-off reversing valve (9) can selectively open or close the shut-off port four (22) and the shut-off port two (20) according to the pressure of the shut-off port three (21).

5. The differential pressure regulating valve with emergency shut-off and anti-backflow functions according to claim 4, characterized in that, The anti-backflow reversing valve (7), the reset reversing valve (8), and the shut-off reversing valve (9) all include a reversing valve body and a reversing valve core. The reversing valve core moves within the reversing valve body to switch the connection state.

6. The differential pressure regulating valve with emergency shutdown and anti-backflow function according to claim 1, characterized in that, The valve core assembly includes a valve stem (33) and a valve plate (34). The valve stem (33) is connected to the main valve diaphragm (2), and the valve plate (34) is disposed in the part of the valve stem (33) located in the flow cavity (6).

7. The differential pressure regulating valve with emergency shut-off and anti-backflow functions according to claim 1, characterized in that, The differential pressure regulating valve also includes a regulating needle valve (35), and the anti-backflow reversing valve (7) is connected to the control chamber (5) via the regulating needle valve (35).

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