An adjustable differential pressure control valve

Abstract

This utility model discloses an adjustable differential pressure control valve, including a valve body, valve cover, diaphragm, and valve stem. The main features include a guide assembly and a sealing ring between the valve stem and valve cover. This allows the valve stem to move vertically and sealably within the valve cover, while also restricting rotation of the diaphragm caused by the valve stem. Due to the dual design of guidance and sealing, sealing performance is ensured even during the valve stem's vertical movement. This allows the pressure spring located on top of the valve cover to effectively isolate the valve body from contact corrosion by the medium, thus extending the lifespan of the pressure spring and ensuring structural stability. Simultaneously, the valve disc is fitted into a guide bushing within the valve body. This guide bushing also completely encloses the bent portion of the diaphragm. Therefore, the guide bushing guides the smooth vertical movement of the valve disc and allows the bent portion to roll axially along the inner wall of the guide bushing during valve disc movement, preventing the bent portion from being directly impacted by the medium and causing strong vibrations, thus ensuring stable diaphragm operation.

Description

Technical Field

[0001] This utility model relates to a control valve, specifically an adjustable differential pressure control valve. Background Technology

[0002] An adjustable differential pressure control valve typically consists of a valve body, a valve cover sealed on top of the valve body, and a diaphragm sealed between the valve cover and the top of the valve body. A closed upper cavity is formed between the diaphragm and the valve cover, and a valve disc is located below the diaphragm. Simultaneously, a valve stem, mounted vertically, is located within the valve cover above the diaphragm. The lower ends of the valve disc, diaphragm, and valve stem are fixed together, creating a bend between the outer periphery of the diaphragm and the valve disc. A pressure spring is also located outside the valve stem. The spring force generated by this pressure spring pushing against the valve stem, combined with the force within the upper cavity, creates a dynamic balance. Therefore, the adjustable differential pressure control valve can effectively solve the problem of inconsistent flow rates in statically balanced systems due to fluctuations in system differential pressure. However, existing adjustable differential pressure control valves have limitations in the valve stem's movement within the valve cover. Figure 5 As shown, the main feature is that the valve cover hole is set as a polygonal through hole, and the valve stem is a polygonal shaft fitted with this polygonal through hole. This allows the valve stem to be restricted from rotating without affecting its lifting and lowering movement. However, this structure usually cannot achieve a sealing function, so the pressure spring placed inside the valve cover cannot effectively isolate the contact corrosion of the medium inside the valve body. Therefore, it is easy to affect the service life and difficult to guarantee the stability of the structure. At the same time, the bending parts of the diaphragm are directly exposed, and they are easily subjected to the impact of the medium during operation, which generates strong vibrations and also affects the stable operation of the diaphragm. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide an adjustable differential pressure control valve that can effectively isolate the pressure spring from the contact corrosion of the medium, extend the service life of the pressure spring and ensure the stability of the structure, and also ensure the smooth operation of the diaphragm.

[0004] The technical problem of this utility model is solved by the following technical solution:

[0005] An adjustable differential pressure control valve includes a valve body, a valve cover sealed on top of the valve body, and a diaphragm sealed between the valve cover and the top of the valve body, forming a closed upper cavity between the diaphragm and the valve cover. A valve disc is located below the diaphragm, and a valve stem, which is vertically mounted, is located inside the valve cover above the diaphragm. The lower ends of the valve disc, diaphragm, and valve stem are fixed together, and a bend is formed between the outer periphery of the diaphragm and the valve disc. A pressure spring is located outside the valve stem, and the spring force generated by the pressure spring pushing against the valve stem interacts with the upper valve body. The forces within the cavity restrain each other to form a dynamic balance. A guide assembly and a sealing ring are provided between the valve stem and the valve cover. The valve stem is guided by the guide assembly and moves up and down within the valve cover in conjunction with the sealing ring, while also restricting the valve stem from causing the diaphragm to rotate. The valve disc is fitted into a guide bushing inside the valve body. The guide bushing also completely encloses the bent portion of the diaphragm and guides the smooth rise and fall of the valve disc. When the valve disc rises and falls, it also causes the bent portion to roll axially along the inner wall of the guide bushing.

[0006] The upper end of the valve stem extends out of the top of the valve cover and is fitted with a pressure spring. The two ends of the pressure spring elastically push against the adjusting nut at the top of the valve cover and the upper end of the valve stem, respectively, and the valve stem is elastically pushed upward by the pressure spring.

[0007] The adjusting nut is threaded onto the upper end of the valve stem, and the preload of the pressure spring is adjusted by rotating the adjusting nut.

[0008] The valve cover is provided with a protective cover that encloses the upper end of the valve stem, the pressure spring, and the adjusting nut.

[0009] The valve cover has an axially penetrating valve cover hole, and the top of the valve cover has a bushing that extends coaxially with the valve cover hole. The valve stem lifting seal is installed in the valve cover hole and the bushing, and a guide assembly is provided between the valve stem and the bushing.

[0010] The sealing ring is a double O-ring disposed between the valve stem and the valve cover hole.

[0011] The guide assembly includes a guide pin that protrudes radially on the outer circumference of the valve stem, and an axially open groove provided on the inner wall of the bushing. The guide pin slides into the axially open groove to restrict the rotation of the valve stem.

[0012] The bending portion is an annular elastic structure, and the rolling deformation of the bending portion changes linearly with the valve disc displacement.

[0013] The valve cover is equipped with a buffer tube assembly, one end of which is connected to the upper cavity and the other end extends to the valve body.

[0014] The valve body has an inlet end and an outlet end at both ends. The valve body has an inlet mounting hole that connects to the inlet end and an outlet mounting hole that connects to the outlet end. Both the inlet mounting hole and the outlet mounting hole are equipped with measuring connectors.

[0015] Compared with the prior art, the present invention mainly features a guide assembly and a sealing ring between the valve stem and the valve cover. The valve stem, guided by the guide assembly and combined with the sealing ring, can move up and down within the valve cover, thus restricting the rotation of the diaphragm caused by the valve stem. Clearly, compared to the traditional single-guide structure with a polygonal shaft and polygonal through-hole, this application adopts a dual-design structure for both guidance and sealing. This ensures sealing performance even when the valve stem moves up and down, allowing the pressure spring placed on top of the valve cover to effectively isolate the valve body from contact corrosion by the medium. This extends the service life of the pressure spring and ensures structural stability. Simultaneously, the valve disc is fitted into a guide bushing within the valve body. This guide bushing also completely encloses the bent portion of the diaphragm. Therefore, the guide bushing guides the smooth up and down movement of the valve disc and causes the bent portion to roll axially along the inner wall of the guide bushing during valve disc movement, thus preventing the bent portion from being directly impacted by the medium and causing strong vibrations, ensuring stable operation of the diaphragm. Attached Figure Description

[0016] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0017] Figure 2 for Figure 1 Top view.

[0018] Figure 3 This is a schematic diagram of the structure after the valve stem and valve cover are installed.

[0019] Figure 4 This is a schematic diagram of the differential pressure control system assembled according to the present invention.

[0020] Figure 5 This is a schematic diagram of the existing structure in which the valve stem is fitted into the polygonal through hole of the valve cover via a polygonal shaft. Detailed Implementation

[0021] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0022] like Figures 1-4As shown, 1. Valve body, 2. Valve disc, 3. Diaphragm, 31. Bending part, 4. Socket head screw, 5. Guide bushing, 6. Fastening nut, 7. Red band measuring connector, 8. Pressure plate, 9. Valve cover, 91. Valve cover hole, 92. Bushing, 921. Axial opening groove, 93. Spring groove, 10. Sealing ring, 11. Valve stem, 12. Buffer tube assembly, 13. Guide pin, 14. Pressure spring, 15. Spring seat, 16. Washer, 17. Adjusting nut, 18. Cotter pin, 19. Protective cover, 20. Bolt, 21. Blue band measuring connector, 22. Upper cavity, 23. Water inlet.

[0023] An adjustable differential pressure control valve, such as Figure 1 , Figure 4 As shown, it is mainly used to solve the problem of constant flow rate in static balance system with fluctuation of system pressure difference. Its structure includes valve body 1, valve cover 9, diaphragm 3 and valve stem 11, etc.

[0024] The valve body 1 has an inlet end for the medium to enter and an outlet end for the medium to flow out at both ends. The valve body 1 has an inlet mounting hole connecting the inlet end and an outlet mounting hole connecting the outlet end, and measuring connectors are provided in both the inlet and outlet mounting holes. In this embodiment, for example… Figure 1 The left side of the view is designated as the inlet end and the right side as the outlet end. The red measuring connector 7 in the inlet mounting hole and the blue measuring connector 21 in the outlet mounting hole are used to distinguish them, so as to facilitate users to quickly master the use of the valve.

[0025] The valve body 1 is provided with a water passage hole 23 and a top hole at the top of the valve body. The top hole overlaps with the axis of the water passage hole 23, and the axis of the water passage hole 23 forms an angle with the axis of the water channel between the inlet and outlet ends. The valve cover 9 is sealed to the top of the valve body by a sealing ring to close the top hole. The valve cover 9 and the valve body 1 can be connected and fastened by multiple bolts 20. At the same time, the outer circumference of a diaphragm 3 is pressed and fixed between the valve cover 9 and the top of the valve body, so that the diaphragm 3 and the valve cover 9 can form a closed upper cavity 22. The diaphragm 3 is a flexible sheet made of rubber. The valve cover 9 is also equipped with a buffer tube assembly 12, one end of which is connected to the upper cavity 22 and the other end extends to the outside of the valve body 1, and can be used for pressure buffering in the upper cavity 22.

[0026] The diaphragm 3 is provided with a valve disc 2 below it, and a valve stem 11 with lifting and sealing installation is provided in the valve cover 9 above the diaphragm 3. Specifically, the valve cover 9 is provided with a valve cover hole 91, which is a through hole that runs along the axis of the valve cover. The top of the valve cover 9 is provided with a bushing 92 that extends coaxially with the valve cover hole 91. Thus, the valve stem 11 can be lifted and installed in the valve cover hole 91 and the bushing 92.

[0027] The valve stem 11 is externally provided with a pressure spring 14, specifically as follows: Figure 3As shown, the upper end of the valve stem 11 extends out of the bushing 92 and protrudes from the top of the valve cover 9. A pressure spring 14 is then fitted onto it. This pressure spring can be a cylindrical spring. One end of the pressure spring 14, i.e. the lower end, is elastically pushed and installed in the spring groove 93 on the top of the valve cover 9. The other end, i.e. the upper end, is elastically pushed against the spring seat 15 on the upper end of the valve stem 11, which is held tightly by the adjusting nut 17. A washer 16 is designed between the adjusting nut 17 and the spring seat 15 for buffering. Therefore, the pressure spring 14 can elastically push the valve stem 11 upward. The spring force generated by the pressure spring pushing against the valve stem can restrain the force in the upper cavity 22 to form a dynamic balance.

[0028] The adjusting nut 17 is threadedly engaged with the upper end of the valve stem 11. Therefore, the preload of the pressure spring 14 can be adjusted by rotating the adjusting nut 17. In other words, the compression of the pressure spring 14 can be adjusted by turning the adjusting nut 17. This causes the force formed in the upper cavity 22 to restrain the spring force of the pressure spring 14, thereby adjusting the range of the valve control pressure difference. Ultimately, this achieves the purpose of adjusting the flow rate and maintaining a constant flow rate. The upper end of the valve stem is also provided with a fixed cotter pin 18 as a locking component for the adjusting nut 17, preventing the adjusting nut 17 from accidentally dislodging from the upper end of the valve stem during the threaded adjustment operation.

[0029] Furthermore, the valve cover 9 is also equipped with a protective cover 19 that covers the upper end of the valve stem, the pressure spring 14 and the adjusting nut 17, so as to protect the internal structure.

[0030] A guide assembly is provided between the valve stem 11 and the valve cover 9, specifically between the valve stem 11 and the bushing 92. This guide assembly includes a guide pin 13 that protrudes radially onto the outer circumferential surface of the valve stem 11. In this embodiment, for example... Figure 3 As shown, the guide pin 13 is transversely inserted along the cross-sectional diameter line of the valve stem 11, with both ends of the guide pin 13 symmetrically exposed on the outer circumference of the valve stem 11, thus forming a radial protrusion on the valve stem 11. Therefore, the inner wall of the bushing 92 also needs to be provided with symmetrically positioned axially open slots 921 to be respectively matched with the two ends of the guide pin 13. Thus, the axial sliding fit between the guide pin 13 and the axially open slots 921 can restrict the rotation of the valve stem 11. That is, the guide assembly guides the valve stem 11 to only move up and down within the valve cover, and restricts the valve stem 11 from causing the diaphragm 3 to rotate. Of course, since a certain gap needs to be reserved between the valve stem 11 and the bushing 92 to facilitate the up and down movement, even if the guide assembly cannot completely restrict the slight rotation of the valve stem 11 caused by the gap, it will not affect the working stability of the diaphragm 3. Moreover, the structural design of this guide assembly is simple and easy to process.

[0031] Then, a sealing ring 10 is provided between the valve stem 11 and the valve cover hole 91, in this embodiment, for example... Figure 1The diagram shows a double O-ring used as a dynamic seal for the valve stem's lifting and lowering movement.

[0032] Obviously, compared with the traditional single-guide structure with polygonal shaft and polygonal through hole, this application adopts a dual design structure of guidance and sealing. It can ensure sealing performance when the valve stem 11 moves up and down. This allows the pressure spring 14 placed on the top of the valve cover 9 to effectively isolate the contact corrosion of the medium in the valve body 1. Therefore, it not only extends the service life of the pressure spring 14, but also ensures the stability of the structure.

[0033] Then, the valve disc 2, diaphragm 3, and lower end of valve stem 11 are fixed together by pressure plate 8, fastening nut 6, and internal hexagon screw 4, so that the outer periphery of diaphragm 3 and valve disc 2 form a bent portion 31 of the diaphragm. This bent portion is an annular elastic structure. In actual operation, when valve stem 11 drives diaphragm 3 and valve disc 2 to move up and down synchronously, the up and down movement of valve disc will cause the bent portion 31 to roll, and the amount of rolling deformation of the bent portion changes linearly with the displacement of valve disc.

[0034] Meanwhile, the valve disc 2 is fitted inside a cylindrical guide bushing 5, which is sealed and fixed inside the valve body 1 by a sealing ring. The guide bushing 5 also completely encloses the bent portion 31 of the diaphragm 3. Therefore, the valve disc 2 and the diaphragm 3, which are enclosed together by the guide bushing 5, can guide the valve disc 2 to move smoothly up and down inside the guide bushing 5. When the valve disc moves up and down, it can also drive the bent portion 31 of the diaphragm 3 to roll axially along the inner wall of the guide bushing 5, thereby avoiding the bent portion 31 from being directly impacted by the medium and generating strong vibration, thus ensuring the stable operation of the diaphragm 3.

[0035] The valve stem 11 drives the valve disc 2 and diaphragm 3 to move up and down, and the axis of the movement overlaps with the axis of the water passage 23, so that the valve disc 2 can more reliably seal and open and close the water passage 23.

[0036] The basic principles and main features of this utility model have been described above. Those skilled in the art should understand that this utility model is not limited to the above embodiments. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the utility model as claimed. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An adjustable differential pressure control valve, comprising a valve body (1), a valve cover (9) sealed and installed on the top of the valve body, and a diaphragm (3) sealed and installed between the valve cover (9) and the top of the valve body (1), wherein the diaphragm and the valve cover (9) form a closed upper cavity (22); a valve disc (2) is provided below the diaphragm (3), and a valve stem (11) is provided in the valve cover (9) above the diaphragm (3) and is installed in a lifting manner, wherein the lower ends of the valve disc (2), the diaphragm (3) and the valve stem (11) are fixed together, and a bent portion (31) of the diaphragm (3) is formed between the outer periphery of the diaphragm (3) and the valve disc (2); a pressure spring (14) is provided outside the valve stem (11), and the spring force formed by the pressure spring pushing on the valve stem (11) and the force in the upper cavity (22) mutually restrain each other to form a dynamic balance, characterized in that A guide assembly and a sealing ring (10) are provided between the valve stem (11) and the valve cover (9). The valve stem (11) is guided by the guide assembly and moves up and down in the valve cover (9) in conjunction with the sealing ring (10). At the same time, the valve stem also restricts the rotation of the diaphragm (3). The valve disc (2) is fitted in the guide bushing (5) inside the valve body (1). The guide bushing also wraps the entire bent part (31) of the diaphragm (3) inside. The guide bushing (5) guides the smooth rise and fall of the valve disc (2) and drives the bent part (31) to roll axially along the inner wall of the guide bushing (4) when the valve disc rises and falls.

2. The adjustable differential pressure control valve according to claim 1, characterized in that... The upper end of the valve stem (11) extends out of the top of the valve cover (9) and is fitted with a pressure spring (14). The two ends of the pressure spring elastically push against the top of the valve cover (9) and the adjusting nut (17) at the upper end of the valve stem (11), and the valve stem (11) is elastically pushed upward by the pressure spring (14).

3. The adjustable differential pressure control valve according to claim 2, characterized in that... The adjusting nut (17) is threaded to the upper end of the valve stem (11), and the preload of the pressure spring (14) is adjusted by rotating the adjusting nut (17).

4. An adjustable differential pressure control valve according to claim 2, characterized in that... The valve cover (9) is provided with a protective cover (19) that covers the upper end of the valve stem, the pressure spring (14) and the adjusting nut (17).

5. An adjustable differential pressure control valve according to claim 1, characterized in that... The valve cover (9) is provided with an axially penetrating valve cover hole (91), and the top of the valve cover (9) is provided with a bushing (92) that extends coaxially with the valve cover hole (91). The valve stem (11) is installed in the valve cover hole (91) and the bushing (92) with a lifting seal, and a guide assembly is provided between the valve stem (11) and the bushing (92).

6. An adjustable differential pressure control valve according to claim 5, characterized in that... The sealing ring (10) is a double O-ring disposed between the valve stem (11) and the valve cover hole (91).

7. An adjustable differential pressure control valve according to claim 5, characterized in that... The guide assembly includes a guide pin (13) that protrudes radially on the outer circumference of the valve stem (11) and an axial opening groove (921) provided on the inner wall of the bushing (92). The axial sliding engagement between the guide pin (13) and the axial opening groove (921) restricts the rotation of the valve stem (11).

8. An adjustable differential pressure control valve according to claim 1, characterized in that... The bending part (31) is an annular elastic structure, and the rolling deformation of the bending part (31) changes linearly with the displacement of the valve disc (2).

9. An adjustable differential pressure control valve according to claim 1, characterized in that... A buffer tube assembly (12) is installed on the valve cover (9), one end of which is connected to the upper cavity (22) and the other end extends to the outside of the valve body (1).

10. An adjustable differential pressure control valve according to claim 1, characterized in that... The valve body (1) has an inlet end and an outlet end at both ends. The valve body (1) has an inlet mounting hole that connects to the inlet end and an outlet mounting hole that connects to the outlet end. Both the inlet mounting hole and the outlet mounting hole are equipped with measuring connectors.

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