Anti-backflow differential pressure regulating valve with leakage protection

Abstract

This invention relates to the field of valve body technology; it proposes an anti-backflow differential pressure regulating valve with leakage protection, comprising 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 within the valve cavity and divides the valve cavity into a control cavity and a flow cavity. The differential pressure regulating valve also includes a check valve core. The valve core assembly and the check valve core are sequentially disposed within the flow cavity, with an intermediate cavity between them. The valve core assembly is connected to the main valve diaphragm. The deformation of the main valve diaphragm controls the opening or closing of the flow cavity by the valve core assembly. The check valve core opens unidirectionally from the inlet end to the outlet end. The differential pressure regulating valve also includes an anti-backflow directional valve, a differential pressure pilot valve, and a leakage protection valve. The inlet end, the anti-backflow directional valve, the control cavity, the differential pressure pilot valve, and the outlet end are sequentially connected to enable the differential pressure regulating valve to be in a dynamic differential pressure regulating state. This technical solution solves the problem of the difficulty in maintaining the long-term reliability of anti-backflow valves in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of valve body technology, and more specifically, to an anti-backflow differential pressure regulating valve with leakage protection. Background Technology

[0002] A differential pressure valve is a type of valve used to control pressure differences in fluid systems and is widely used in various industrial equipment. It maintains the pressure difference within the system within a set range by adjusting the valve's opening, ensuring normal equipment operation. The working principle of a differential pressure valve is based on pressure sensing; when the system pressure exceeds or falls below a set value, the valve automatically adjusts to restore balance.

[0003] Despite significant advancements in differential pressure valve technology, several challenges remain in practical applications. For instance, traditional differential pressure valves often continue to supply water while simultaneously draining large volumes of water in response to downstream emergencies, leading to substantial water waste. Furthermore, they lack reliable backflow prevention when downstream pressure rises, especially in cases of potential downstream contamination. While some valves are designed with emergency shut-off functions, their reliability decreases with use due to deteriorating sealing. Therefore, a valve body capable of addressing these issues is urgently needed. Summary of the Invention

[0004] This invention proposes an anti-backflow differential pressure regulating valve with leakage protection, which solves the problem that the reliability of valve anti-backflow is difficult to maintain for a long time in the prior art.

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

[0006] A differential pressure regulating valve with backflow prevention and leakage protection 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 differential pressure regulating valve also includes a check valve core. The valve core assembly and the check valve core are sequentially disposed in the flow cavity, with an intermediate cavity between the valve core assembly and the check valve core. The valve core assembly is connected to the main valve diaphragm. The main valve diaphragm deforms to control the valve core assembly to open or close the flow cavity. The check valve core opens unidirectionally from the inlet end to the outlet end. The differential pressure regulating valve also includes an anti-backflow reversing valve, a differential pressure pilot valve, and a leakage protection valve. The inlet end, the anti-backflow reversing valve, the control cavity, the differential pressure pilot valve, and the outlet end are sequentially connected to enable the differential pressure regulating valve to be in a dynamic differential pressure regulation state.

[0007] 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 emergency shut-off state and closes, and the check valve core closes in reverse.

[0008] When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the leakage protection valve selectively puts the intermediate cavity into a differential pressure protection state or a leakage protection state according to the pressure difference between the intermediate cavity and the inlet end.

[0009] The anti-backflow reversing 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 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 differential pressure 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 differential pressure chamber. The differential pressure chamber is connected to the communicating chamber via the pilot valve port one. The inlet end is connected, and both the second and third pilot valve ports are connected to the connecting cavity. When the differential pressure regulating valve is in the differential pressure dynamic adjustment state, the first anti-backflow port is connected to the inlet end. The anti-backflow reversing valve connects the second and third anti-backflow ports according to the pressure of the first anti-backflow port. The inlet end, the second anti-backflow port, the third anti-backflow port, the control cavity, the second pilot valve port, the third pilot valve port, and the outlet end can be connected in sequence.

[0010] 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.

[0011] The drain protection valve includes a connection port one, a connection port two, a connection port three, and a drain port. The drain protection valve includes a drain valve body, a drain valve core, and a drain spring. The connection port one is connected to the water inlet end. The connection ports two and three are both connected to the intermediate cavity. The connection ports one and three act on the two ends of the drain valve core, respectively. The drain spring is located at the end of the drain valve core near the connection port two. The drain valve core can move according to the pressure difference between the two ends to selectively connect the connection port two and the drain port.

[0012] The relief protection valve also includes an adjusting bolt, which is disposed on the relief valve housing, and the portion of the adjusting bolt located inside the relief valve housing abuts against the relief spring.

[0013] The check valve core includes a check bracket, a check spring, a check rod, and a check plate. The check bracket is disposed within the flow chamber. The check rod is movably disposed on the check bracket. The check plate is disposed on the check rod near the outlet end. The check spring is sleeved on the check rod, and the check spring causes the check rod to tend to move towards the outlet end. The movement of the check rod causes the check plate to open or close the flow chamber.

[0014] The anti-backflow reversing valve includes a reversing valve body and a reversing valve core, wherein 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 an anti-backflow differential pressure regulating valve with leakage protection. By setting an anti-backflow reversing valve, a leakage protection valve, and a differential pressure pilot valve on the main valve body, after the differential pressure regulating valve is opened, the connection state of each component is adjusted so that the entire valve body is in a dynamic differential pressure regulation state. At this time, the valve body dynamically adjusts the pressure difference between the inlet and outlet. When the pressure at the outlet suddenly increases, and may be accompanied by water pollution, the check valve core closes in reverse and the connection state of each component is adjusted, so that the valve core assembly closes urgently. At this time, the reliability of anti-backflow is improved by the two anti-backflow designs. Based on this, considering the decay of the seal of the check valve core, the intermediate cavity also has the function of allowing the intermediate cavity to leak through the leakage protection valve. So even if the seal of the check valve core decays, the intermediate cavity can still leak, which plays a further role in anti-backflow protection. Based on the above solution, the problem of the difficulty in maintaining the reliability of valve anti-backflow in the long term in the prior art can be solved. 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 valve body in its initial state in this invention;

[0021] Figure 2 This is a schematic diagram of the valve body in the pressure reduction dynamic adjustment state in this invention;

[0022] Figure 3This is a schematic diagram of the valve body in the closed and venting state in this invention.

[0023] In the diagram: 1. Main valve body; 2. Main valve diaphragm; 3. Inlet; 4. Outlet; 5. Control chamber; 6. Flow chamber; 7. Check valve core; 8. Intermediate chamber; 9. Anti-backflow directional valve; 10. Differential pressure pilot valve; 11. Relief protection valve; 12. Anti-backflow port one; 13. Anti-backflow port two; 14. Anti-backflow port three; 15. Pilot valve port one; 16. Pilot valve port two; 17. Pilot valve port three; 18. Pilot valve body; 19. Pilot valve diaphragm; 20. Preload spring; 21. Pilot valve core. 22. Differential pressure chamber; 23. Connecting chamber; 24. Anti-backflow port four; 25. Anti-backflow port five; 26. Connection port one; 27. Connection port two; 28. Connection port three; 29. ​​Drain port; 30. Drain valve body; 31. Drain valve core; 32. Drain spring; 33. Adjusting bolt; 34. Check bracket; 35. Check spring; 36. Check rod; 37. Check plate; 38. Reversing valve body; 39. Reversing valve core; 40. Valve stem; 41. Valve plate; 42. Adjusting needle valve. Detailed Implementation

[0024] 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.

[0025] like Figures 1-3 As shown in the figure, this embodiment proposes a backflow prevention differential pressure regulating valve with leakage protection. 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 passage cavity 6. The differential pressure regulating valve also includes a check valve core 7. The valve core assembly and the check valve core 7 are sequentially disposed in the flow passage cavity 6. An intermediate cavity 8 is located between the valve core assembly and the check valve core 7. 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 chamber 6. The check valve core 7 opens unidirectionally from the inlet end 3 to the outlet end 4. The differential pressure regulating valve also includes an anti-backflow reversing valve 9, a differential pressure pilot valve 10, and a leakage protection valve 11. The inlet end 3, the anti-backflow reversing valve 9, the control chamber 5, the differential pressure pilot valve 10, and the outlet end 4 are sequentially connected to enable the differential pressure regulating valve to be in a differential pressure dynamic regulation state.

[0026] When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow reversing valve 9 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 emergency shut-off state and closes, and the check valve core 7 closes in reverse.

[0027] When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the leakage protection valve 11 selectively puts the intermediate cavity 8 into the differential pressure protection state or the leakage protection state according to the pressure difference between the intermediate cavity 8 and the water inlet 3.

[0028] In this embodiment, the proposed anti-backflow differential pressure regulating valve with leakage protection has a structure in which a valve cavity is set inside the main valve body 1. The valve cavity has an inlet end 3 and an outlet end 4. A main valve diaphragm 2 is set 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 the valve core assembly. The main valve diaphragm 2 deforms according to the pressure in the control cavity 5, thereby controlling the movement of the valve core assembly. The valve core assembly controls the opening and closing of the flow cavity 6. The main valve body 1 is also provided with a check valve core 7, an anti-backflow reversing valve 9, a leakage protection valve 11, and a differential pressure pilot valve 10. Different connection states form different connection schemes, thereby enabling the differential pressure regulating valve as a whole to be in different states. The differential pressure regulating valve is configured to adapt to different scenarios. In the initial state, the valve core assembly and the check valve core 7 are closed, the water pressure at the inlet 3 increases, and the water pressure reaches the outlet 4 through the anti-backflow reversing valve 9, the control chamber 5, and the differential pressure pilot valve 10. The medium in the control chamber 5 flows to the outlet 4, resulting in a lower water pressure. At this time, the water pressure at the inlet 3 acts on the valve core assembly, thereby opening the valve body. At the same time, the check valve core 7 opens, and the inlet 3 and the outlet 4 are connected. The differential pressure pilot valve 10 senses the water pressure at the outlet 4 and the water pressure at the inlet 3, thereby fine-tuning the opening amount, adjusting the medium distribution flow in the control chamber 5, and then adjusting the deformation of the main valve diaphragm 2 to achieve dynamic differential pressure regulation.

[0029] When the water pressure at the outlet 4 surges and is accompanied by potential contamination, the anti-backflow reversing valve 9 adjusts and switches to disconnect the inlet 3 from the control chamber 5 and connect the outlet 4 to the control chamber 5. Due to the surge in pressure at the outlet 4, the main valve diaphragm 2 responds quickly and deforms under the pressure of the water at the outlet 4, and the valve core assembly closes. At the same time, the check valve core 7 also closes, thus putting the valve body into an emergency shut-off state.

[0030] Based on this, the valve core assembly and the check valve core 7 are closed, and the intermediate cavity 8 is a closed space. Considering the decay of sealing reliability, if the check valve core 7 leaks, causing the pressure in the intermediate cavity 8 to rise, the intermediate cavity 8 will be protected by the relief protection valve 11. According to the pressure difference between the intermediate cavity 8 and the inlet end 3, if the pressure difference between the intermediate cavity 8 and the inlet end 3 reaches a certain threshold, the intermediate cavity 8 will directly vent. If the threshold is not reached, the pressure value of the intermediate cavity 8 will always be less than the pressure value of the inlet end 3, that is, the medium in the intermediate cavity 8 will not flow back to the inlet end 3 side. The above can achieve backflow prevention protection.

[0031] 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.

[0032] The anti-backflow reversing valve 9 includes an anti-backflow port 12, an anti-backflow port 23, and an anti-backflow port 34. The differential pressure pilot valve 10 includes a pilot valve port 15, a pilot valve port 26, and a pilot valve port 37. The differential pressure pilot valve 10 includes a pilot valve body 18, a pilot valve diaphragm 19, a preload spring 20, and a pilot valve core 21. The pilot valve diaphragm 19 divides the pilot valve body 18 into a differential pressure chamber 22 and a connecting chamber 23. The pilot valve core 21 is connected to the pilot valve diaphragm 19. The preload spring 20 is sleeved on the portion of the pilot valve core 21 located within the differential pressure chamber 22. The differential pressure chamber 22 is connected by... The pilot valve port 15 is connected to the inlet 3, and the pilot valve port 26 and the pilot valve port 37 are both connected to the connecting cavity 23. When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow port 12 is connected to the inlet 3. The anti-backflow reversing valve 9 connects the anti-backflow port 23 and the anti-backflow port 34 according to the pressure of the anti-backflow port 12. The inlet 3, the anti-backflow port 23, the anti-backflow port 34, the control cavity 5, the pilot valve port 26, the pilot valve port 37, and the outlet 4 can be connected in sequence.

[0033] In this embodiment, the differential pressure regulating valve is open and the inlet 3 and outlet 4 are in normal operating condition. The differential pressure pilot valve 10 can sense the pressure between the inlet 3 and outlet 4. Specifically, the anti-backflow reversing valve 9 is in one of the reversing positions through the medium pressure of the anti-backflow port 12, so that the anti-backflow port 23 and anti-backflow port 34 are connected. The medium pressure of the inlet 3 enters the control chamber 5 through the anti-backflow port 23 and anti-backflow port 34. The medium pressure in the control chamber 5 can be connected to the differential pressure pilot valve 10 through the pilot valve port 26, and the pilot valve port 317 is connected to the outlet 4. In the differential pressure chamber 22 inside the pilot valve body 18, the preload spring 20 is sleeved on the pilot valve core 21. The medium pressure of the inlet 3 is transmitted to the pilot valve diaphragm 19 through the pilot valve port 26. On the upper surface, the medium pressure at the outlet 4 acts on the pilot valve diaphragm 19 through the pilot valve port 3 17. Initially, under the action of the pre-tightening spring 20, the pilot valve core 21 is in the closed state. After the medium pressure at the inlet 3 is transmitted to the differential pressure chamber 22, the pilot valve core 21 opens. As the valve opens, the pressure at the outlet 4 increases. The pressure at the outlet 4 acts on the pilot valve diaphragm 19, causing the opening of the differential pressure pilot valve 10 to decrease and maintain it in the differential pressure dynamic adjustment state. When the pressure difference between the outlet 4 and the inlet 3 is less than the preset adjusted pressure value, the pre-tightening spring 20 causes the pilot valve core 21 to move and decrease the opening. The flow diversion in the control chamber 5 decreases, and the opening of the valve core assembly control flow chamber 6 decreases. The pressure compensation at the outlet 4 decreases, so that the differential pressure is maintained within the allowable range of the target value. Conversely, the pilot valve core 21 increases the opening.

[0034] The anti-backflow reversing valve 9 also includes an anti-backflow port 4 24 and an anti-backflow port 5 25. The anti-backflow port 4 24 is connected to the water outlet 4. The anti-backflow reversing valve 9 selectively connects or shuts off the anti-backflow port 3 14 and the anti-backflow port 5 25 according to the pressure of the anti-backflow port 4 24. The anti-backflow port 5 25 is connected to the water outlet 4.

[0035] In this embodiment, when the pressure at the outlet 4 suddenly increases, the anti-backflow port 24 of the anti-backflow reversing valve 9 senses the high pressure at the outlet 4. The anti-backflow reversing valve 9 then adjusts the connection state, closing the anti-backflow port 23 and the anti-backflow port 34, and connecting the anti-backflow port 34 with the anti-backflow port 525. The anti-backflow port 525 is connected to the outlet 4, and the high pressure at the outlet 4 enters the control chamber 5 through the anti-backflow port 525 and the anti-backflow port 314. The pressure in the control chamber 5 increases instantaneously, causing the differential pressure regulating valve to close quickly and preventing backflow.

[0036] The drain protection valve 11 includes a first connection port 26, a second connection port 27, a third connection port 28, and a drain port 29. The drain protection valve 11 includes a drain valve body 30, a drain valve core 31, and a drain spring 32. The first connection port 26 is connected to the water inlet 3. The second connection port 27 and the third connection port 28 are both connected to the intermediate cavity 8. The first connection port 26 and the third connection port 28 act on both ends of the drain valve core 31. The drain spring 32 is located at the end of the drain valve core 31 near the second connection port 27. The drain valve core 31 can move according to the pressure difference between the two ends to selectively connect the second connection port 27 and the drain port 29.

[0037] In this embodiment, the relief valve 11 provides pressure protection and relief protection for the intermediate cavity 8 by sensing the medium pressure at the inlet end 3 and the intermediate cavity 8. Specifically, the relief valve 11 senses the medium pressure at the inlet end 3 through connection port 1 26 and senses the medium pressure in the intermediate cavity 8 through connection port 3 28. The two ends of the relief valve core 31 sense the medium pressure at the inlet end 3 and the intermediate cavity 8, respectively. A relief spring 32 is also provided on the side near connection port 3 28. Therefore, the relief valve core 31 will only move when the medium pressure in the intermediate cavity 8 and the elastic force of the relief spring 32 are greater than the medium pressure at the inlet end 3. After the relief valve core 31 moves, the connection port 2 27 and the relief port 29 will then open. When the differential pressure regulating valve is shut off from the backflow emergency stop, the intermediate chamber 8 is closed by the valve core assembly and the check valve core 7. When the combined force of the medium pressure in the intermediate chamber 8 and the spring force of the relief spring 32 is still less than the medium pressure at the inlet end 3, the relief protection valve 11 keeps the pressure value in the intermediate chamber 8 at a lower protection value to prevent backflow to the inlet end 3 due to the decay of the sealing reliability of the valve core assembly. When the combined force of the medium pressure in the intermediate chamber 8 and the spring force of the relief spring 32 is greater than the medium pressure at the inlet end 3, the relief valve core 31 moves, connecting the second connection port 27 and the relief port 29, and the intermediate chamber 8 leaks and reduces pressure until the relief valve core 31 moves back to its original position, and the second connection port 27 and the relief port 29 are disconnected, thereby protecting the intermediate chamber 8 from leakage.

[0038] The relief protection valve 11 also includes an adjusting bolt 33, which is disposed on the relief valve housing 30. The portion of the adjusting bolt 33 located inside the relief valve housing 30 abuts against the relief spring 32.

[0039] In this embodiment, an adjusting bolt 33 is provided on the relief protection valve 11. The compression of the relief spring 32 is adjusted by rotating the adjusting bolt 33 to the depth of screwing into the relief valve housing 30, thereby adjusting the operating pressure difference between the intermediate cavity 8 and the water inlet 3. The so-called operating pressure difference means that when it exceeds the operating pressure difference, the relief valve core 31 will perform a switching action.

[0040] The check valve core 7 includes a check bracket 34, a check spring 35, a check rod 36, and a check plate 37. The check bracket 34 is disposed within the flow chamber 6. The check rod 36 is movably disposed on the check bracket 34. The check plate 37 is disposed on the check rod 36 near the outlet end 4. The check spring 35 is sleeved on the check rod 36. The check spring 35 causes the check rod 36 to tend to move towards the outlet end 4. The movement of the check rod 36 causes the check plate 37 to open or close the flow chamber 6.

[0041] In this embodiment, a check bracket 34 is provided in the flow cavity 6, and a check rod 36 passes through the middle of the check bracket 34. A check spring 35 is sleeved on the part of the check rod 36 that passes through the check bracket 34. When the check spring 35 is compressed, its elastic force causes the check rod 36 to tend to move towards the side closer to the water inlet end 3. The check plate 37 on the check rod 36 is on the side closer to the water outlet end 4. When the pressure changes from high to low along the direction from the water inlet end 3 to the water outlet end 4, the pressure of the medium acting on the check plate 37 overcomes the elastic force of the check spring 35, thus conducting. When the pressure at the water outlet end 4 increases, the check plate 37 closes under the action of the check spring 35, thus closing the flow cavity 6.

[0042] The anti-backflow reversing valve 9 includes a reversing valve housing 38 and a reversing valve core 39, wherein the reversing valve core 39 moves within the reversing valve housing 38 to switch the connection state.

[0043] In this embodiment, the anti-backflow reversing valve 9 adopts a structure in which a reversing valve core 39 is set inside the reversing valve housing 38. By means of medium pressure, spring force or external pressing force, the reversing valve core 39 can be moved to adjust the connection state and realize different working states of the differential pressure regulating valve.

[0044] The valve core assembly includes a valve stem 40 and a valve plate 41. The valve stem 40 is connected to the main valve diaphragm 2, and the valve plate 41 is disposed in the portion of the valve stem 40 located within the flow cavity 6.

[0045] In this embodiment, the valve core assembly consists of a valve stem 40 and a valve plate 41. The valve stem 40 is connected to the main valve diaphragm 2. A guide structure that cooperates with the valve stem 40 is provided in the main valve body 1 so that the deformation of the main valve diaphragm 2 can drive the valve stem 40 to move. A valve plate 41 is provided at the end of the valve stem 40. The valve plate 41 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.

[0046] The differential pressure regulating valve also includes a regulating needle valve 42, and the anti-backflow reversing valve 9 is connected to the control chamber 5 via the regulating needle valve 42.

[0047] In this embodiment, the anti-backflow reversing valve 9 is connected to the control chamber 5 through the regulating needle valve 42. The regulating needle valve 42 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 42 and control the flow rate of the diverted flow.

[0048] 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 reverse flow protected, reverse flow preventing pressure differential regulating valve, 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 differential pressure regulating valve also includes a check valve core (7). The valve core assembly and the check valve core (7) are sequentially disposed in the flow cavity (6). An intermediate cavity (8) is formed between the valve core assembly and the check valve core (7). 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 check valve... The core (7) opens unidirectionally from the water inlet (3) to the water outlet (4). The differential pressure regulating valve also includes an anti-backflow reversing valve (9), a differential pressure pilot valve (10), and a leakage protection valve (11). The water inlet (3), the anti-backflow reversing valve (9), the control chamber (5), the differential pressure pilot valve (10), and the water outlet (4) are connected in sequence to make the differential pressure regulating valve in a differential pressure dynamic regulation state. The differential pressure pilot valve (10) can sense the water pressure at the water outlet (4) and the water pressure at the water inlet (3), adjust the medium flow rate in the control chamber (5), and then adjust the deformation of the main valve diaphragm (2) to achieve differential pressure dynamic regulation. When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow reversing valve (9) 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 emergency shut-off state and closes, and the check valve core (7) closes in the reverse direction. When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the leakage protection valve (11) selectively puts the intermediate cavity (8) into the differential pressure protection state or the leakage protection state according to the pressure difference between the intermediate cavity (8) and the inlet end (3); The drain protection valve (11) includes a first connection port (26), a second connection port (27), a third connection port (28), and a drain port (29). The drain protection valve (11) includes a drain valve body (30), a drain valve core (31), and a drain spring (32). The first connection port (26) is connected to the inlet end (3). The second connection port (27) and the third connection port (28) are both connected to the intermediate cavity (8). The first connection port (26) and the third connection port (28) act on the two ends of the drain valve core (31). The drain spring (32) is located at the end of the drain valve core (31) near the second connection port (27). The drain valve core (31) can move according to the pressure difference between the two ends so that the second connection port (27) and the drain port (29) can be selectively connected.

2. A reverse flow protected check pressure regulating valve with blowdown according to claim 1, characterized in that The anti-backflow reversing valve (9) includes an anti-backflow port one (12), an anti-backflow port two (13), and an anti-backflow port three (14). The differential pressure pilot valve (10) includes a pilot valve port one (15), a pilot valve port two (16), and a pilot valve port three (17). The differential pressure pilot valve (10) includes a pilot valve body (18), a pilot valve diaphragm (19), a preload spring (20), and a pilot valve core (21). The pilot valve diaphragm (19) divides the pilot valve body (18) into a differential pressure chamber (22) and a connecting chamber (23). The pilot valve core (21) is connected to the pilot valve diaphragm (19). The preload spring (20) is sleeved on the portion of the pilot valve core (21) located within the differential pressure chamber (22). 22) The pilot valve port 1 (15) is connected to the inlet end (3), the pilot valve port 2 (16) and the pilot valve port 3 (17) are both connected to the connecting cavity (23). When the differential pressure regulating valve is in the differential pressure dynamic regulation state, the anti-backflow port 1 (12) is connected to the inlet end (3). The anti-backflow reversing valve (9) connects the anti-backflow port 2 (13) and the anti-backflow port 3 (14) according to the pressure of the anti-backflow port 1 (12). The inlet end (3), the anti-backflow port 2 (13), the anti-backflow port 3 (14), the control cavity (5), the pilot valve port 2 (16), the pilot valve port 3 (17) and the outlet end (4) can be connected in sequence.

3. The anti-backflow differential pressure regulating valve with leakage protection according to claim 2, characterized in that, The anti-backflow reversing valve (9) also includes an anti-backflow port four (24) and an anti-backflow port five (25). The anti-backflow port four (24) is connected to the water outlet (4). The anti-backflow reversing valve (9) selectively connects or shuts off the anti-backflow port three (14) and the anti-backflow port five (25) according to the pressure of the anti-backflow port four (24). The anti-backflow port five (25) is connected to the water outlet (4).

4. The anti-backflow differential pressure regulating valve with leakage protection according to claim 1, characterized in that, The relief protection valve (11) also includes an adjusting bolt (33), which is disposed on the relief valve housing (30), and the portion of the adjusting bolt (33) located inside the relief valve housing (30) abuts against the relief spring (32).

5. The anti-backflow differential pressure regulating valve with leakage protection according to claim 3, characterized in that, The check valve core (7) includes a check bracket (34), a check spring (35), a check rod (36), and a check plate (37). The check bracket (34) is disposed in the flow chamber (6). The check rod (36) is movably disposed on the check bracket (34). The check plate (37) is disposed on the check rod (36) on the side near the outlet end (4). The check spring (35) is sleeved on the check rod (36). The check spring (35) causes the check rod (36) to have a tendency to move towards the outlet end (4). The movement of the check rod (36) causes the check plate (37) to open or close the flow chamber (6).

6. The anti-backflow differential pressure regulating valve with leakage protection according to claim 3, characterized in that, The anti-backflow reversing valve (9) includes a reversing valve housing (38) and a reversing valve core (39), wherein the reversing valve core (39) moves within the reversing valve housing (38) to switch the connection state.

7. The anti-backflow differential pressure regulating valve with leakage protection according to claim 6, characterized in that, The valve core assembly includes a valve stem (40) and a valve plate (41). The valve stem (40) is connected to the main valve diaphragm (2), and the valve plate (41) is disposed in the part of the valve stem (40) located in the flow cavity (6).

8. The anti-backflow differential pressure regulating valve with leakage protection according to claim 7, characterized in that, The differential pressure regulating valve also includes a regulating needle valve (42), and the anti-backflow reversing valve (9) is connected to the control chamber (5) via the regulating needle valve (42).

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