A multi-layer fluoropolymer-lined bellows regulating valve

Abstract

A multi-layer fluoropolymer-lined bellows control valve includes a valve body, valve seat, valve core, valve stem, actuator, valve cover, and packing seal assembly. The valve body and valve cover are connected to form a valve cavity. The valve seat is fixed within the valve body. The valve stem passes through the valve cover, with one end located inside the valve cavity and connected to the valve core, and the other end located above the valve cavity and connected to the actuator. The actuator drives the valve stem to slide axially. The valve seat includes a central support core and a valve seat covering layer. The upper end of the central support core has a groove, and a hollow elastic metal ring is fixed in the groove. The valve seat covering layer covers the outer periphery of the valve seat body formed by the connection of the central support core and the hollow elastic metal ring. The valve seat covering layer is made of elastic fluoroplastic material. This utility model provides a multi-layer fluoropolymer-lined bellows control valve with a compact structure that eliminates the wear problem between the valve core and valve seat.

Description

Technical Field

[0001] This utility model relates to the field of regulating valve technology, specifically a multi-layer fluoropolymer-lined bellows regulating valve. Background Technology

[0002] The multi-layer fluoropolymer-lined bellows control valve is a specially structured control valve with excellent corrosion resistance and sealing performance. Its main structure has multiple layers, including a support layer, a first protective layer, and a second protective layer. The support layer provides basic structural support, ensuring the overall strength of the control valve. The first protective layer, typically made of stainless steel, is located on the inner surface of the support layer and enhances the structural strength and stability of the control valve. The second protective layer is made of fluoropolymer-lined plastic, possessing excellent corrosion resistance and directly contacting the medium to prevent corrosion of the valve's internal structure.

[0003] In the main structure, the valve core and valve seat are sealed by the contact between the fluoroplastic lining on the surface of the valve core and the fluoroplastic lining on the surface of the valve seat. The seal is not reliable enough, and the fluoroplastic lining layer, and even the inner structure, are prone to wear. In addition, the medium is prone to leakage from the gap in the valve stem movement.

[0004] Therefore, this utility model proposes a multi-layer fluoropolymer-lined bellows regulating valve with a compact structure that can eliminate the wear problem between the valve core and the valve seat. Utility Model Content

[0005] The purpose of this utility model is to overcome the shortcomings and deficiencies of the existing technology and to provide a multi-layer fluoropolymer-lined bellows control valve. It has the advantages of compact structure and can eliminate leakage caused by wear between valve core and valve seat. It solves the problem in the above-mentioned background technology that the fluoropolymer-lined plastic on the surface of valve core and the fluoropolymer-lined plastic on the surface of valve seat are not reliable enough in forming a seal, and the fluoropolymer-lined plastic layer, and even the inner structure, are prone to wear, and the medium is prone to leakage from the gap of valve stem movement.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A multi-layer fluoropolymer-lined bellows regulating valve includes a valve body, a valve seat, a valve core, a valve stem, an actuator, a valve cover, and a packing seal assembly. The valve body and the valve cover are connected to form a valve cavity. The valve seat is fixed in the valve body. The valve stem passes through the valve cover, with one end located inside the valve cavity and connected to the valve core, and the other end located above the valve cavity and connected to the actuator. The actuator drives the valve stem to slide axially. The valve seat includes a central support core and a valve seat covering layer. The upper end of the central support core is provided with a groove, and a hollow elastic metal ring is fixed in the groove. The valve seat covering layer covers the outer periphery of the valve seat body formed by the connection of the central support core and the hollow elastic metal ring. The valve seat covering layer is made of elastic fluoroplastic material.

[0007] By adopting the above technical solution, the valve seat has an elastic hollow metal ring and an outer layer covering the valve seat, which can eliminate the problem of leakage caused by wear between the valve core and the valve seat.

[0008] The present invention is further configured such that the hollow elastic metal ring has a circular cross-section, the groove has a semi-circular cross-section and is adapted to the outer diameter of the hollow elastic metal ring, and the hollow elastic metal ring is fixedly connected to the contact surface of the central support core.

[0009] By adopting the above technical solution, the hollow elastic metal ring with a circular cross-section is set in the groove of the semi-circular cross-section at the upper end of the central support core. The contact surfaces of the two can be welded or fixedly connected with adhesive materials. This structure can enhance the stability of the hollow elastic metal ring, and the outer layer of the valve seat is not easily damaged when it contacts the valve core.

[0010] The present invention is further configured such that a mating groove is formed on the outer periphery of the lower end of the valve seat, and a limiting step ring is provided in the valve body. The mating groove and the limiting step ring are inserted and mated, and a sealing ring is provided between the two.

[0011] By adopting the above technical solution, the sealing ring is disposed between the mating groove formed on the outer periphery of the lower end of the valve seat and the limiting step ring disposed in the valve body, thereby enhancing the sealing performance between the two when the valve is closed.

[0012] The present invention is further configured such that the valve core includes a first conical surface and a second conical surface, the first conical surface abuts against the outer layer covering the valve seat, causing the outer layer covering the valve seat to deform and the two to contact more closely; the second conical surface is located on the lower side of the valve core and can be inserted into the valve seat.

[0013] By adopting the above technical solution, the first conical surface abuts against the valve seat, causing the outer layer of the valve seat and the hollow elastic metal ring to deform, so that the valve core and the valve seat can be in closer contact; the second conical surface can be inserted into the valve core, and when the valve stem deviates from the axial path, the second conical surface contacts the valve seat, which can guide the valve stem and valve core to the normal movement path, thus having a guiding function.

[0014] The present invention is further configured to include a PTFE bellows sleeved outside the valve stem and a packing seal assembly fixed between the valve cover and the valve stem, wherein the packing seal assembly is disposed above the PTFE bellows.

[0015] By adopting the above technical solution, the PTFE bellows and packing seal assembly form a double sealing structure with the valve stem, making it difficult for the medium to leak from the gaps when the valve stem moves, thus enhancing the sealing performance.

[0016] The present invention is further configured such that the valve cover includes an upper valve cover and a lower valve cover, the upper end of the PTFE bellows is sandwiched between the upper valve cover and the lower valve cover, the lower end is fixedly connected to the outer periphery of the valve stem, and a first sealing ring and a second sealing ring are respectively provided between the upper end of the PTFE bellows and the upper valve cover and the lower valve cover.

[0017] By adopting the above technical solution, the PTFE bellows is externally disposed on the outer periphery of the valve stem and its upper end is fixedly clamped between the valve cover, separating the valve cavity from the actuator and forming a dynamic sealing structure, which effectively prevents the medium from leaking into the actuator from the gap due to the movement of the valve stem, thus affecting the normal operation of the regulating valve.

[0018] The present invention is further configured such that the packing sealing assembly includes packing, a pressure ring, and a pressure cap. The packing is disposed in the stuffing box of the upper valve cover and closely adheres to the outer periphery of the valve stem. The packing is flexible and has an annular groove that allows the pressure ring to extend into. The upper end of the pressure cap has a larger area than the lower end, and the upper end opening can be fixedly connected to the upper valve cover. The lower end is adapted to the pressure ring.

[0019] By adopting the above technical solution, the packing seal assembly is set inside the stuffing box and located above the PTFE bellows, forming a static seal structure. After long-term operation, if the PTFE bellows is damaged and the medium flows out of the valve cavity, the packing seal assembly can further prevent medium leakage, and the valve can still be used normally, providing a double insurance function.

[0020] The present invention is further configured such that the lower end cross-section of the pressure ring adopts a structure that is wider at the top and narrower at the bottom.

[0021] By adopting the above technical solution, when the pressure ring compresses the packing, the pressure ring adopts a structure that is wider at the top and narrower at the bottom, so as to squeeze the packing more tightly and further improve the sealing performance. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of this utility model.

[0023] Figure 1 This is a schematic diagram of the overall structure of the multi-layer fluoropolymer-lined bellows regulating valve of this utility model;

[0024] Figure 2 for Figure 1 An enlarged structural diagram of point A in the structure;

[0025] Figure 3 for Figure 1 A magnified structural diagram at point B in the structure;

[0026] In the diagram, 1-valve body; 10-multi-layer fluoropolymer lining; 101-stainless steel layer; 102-fluoropolymer-lined plastic layer;

[0027] 2-Valve seat; 20-Central support core; 21-Valve seat outer layer; 22-Hollow elastic metal ring; 201-Groove;

[0028] 3-Valve core; 30-Pin hole; 31-First conical surface; 32-Second conical surface;

[0029] 4-Valve stem; 5-Actuator;

[0030] 6-Valve cover; 60-Upper valve cover; 61-Lower valve cover; 62-First sealing ring; 63-Second sealing ring;

[0031] 7-PTFE bellows; 8-packing seal assembly; 80-packing; 81-pressure ring; 82-pressure gland.

[0032] 9-Sealing ring. Detailed Implementation

[0033] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.

[0034] It should be noted that all uses of "first" and "second" in the embodiments of this utility model are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of this utility model. Subsequent embodiments will not explain this in detail.

[0035] The directional and positional terms used in this utility model, such as up, down, front, back, left, right, inside, outside, top, bottom, side, etc., are only for reference to the accompanying drawings. Therefore, the directional and positional terms used are for the purpose of explaining and understanding this utility model, and not for limiting the scope of protection of this utility model.

[0036] Example:

[0037] This invention provides a multi-layer fluoropolymer-lined bellows regulating valve with a compact structure that can eliminate leakage caused by wear between the valve core and valve seat.

[0038] Please see Figures 1 to 3In an embodiment of this utility model, a multi-layer PTFE-lined bellows regulating valve includes a valve body 1, a valve seat 2, a valve core 3, a valve stem 4, an actuator 5, a valve cover 6, a PTFE bellows 7, a packing seal assembly 8, and a sealing ring 9. The valve cover 6 includes an upper valve cover 60 and a lower valve cover 61. The valve body 1 is connected to the lower valve cover 61 to form a valve cavity. The valve seat 2 is fixed on the valve body 1. The sealing ring 9 is disposed between the valve seat 2 and the valve body 1, and the valve seat 2 and the valve body 1 are connected by the sealing ring 9. The valve core 3 includes a pin hole 30 and is connected to the valve stem 4 by a cylindrical pin. The valve stem 4 passes through the valve cover 6, with one end located inside the valve cavity and connected to the valve core 3, and the other end located above the valve cavity and connected to the actuator 5. The actuator 5 drives the valve stem 4 to slide axially. The valve cover 6 also includes a first sealing ring 62 and a second sealing ring 63. 3. The PTFE bellows 7 is sleeved around the outer periphery of the valve stem 4, with its upper end sandwiched between the upper valve cover 60 and the lower valve cover 61, and forms a tight contact with the first sealing ring 62 and the second sealing ring 63; the packing sealing assembly 8 includes packing 80, a pressure ring 81, and a pressure cap 82. The packing 80 is disposed in the stuffing box of the upper valve cover 60. The upper end of the packing 80 has a groove for the pressure ring 81 to extend into. Both the pressure ring 81 and the pressure cap 82 have through holes for the valve stem 4 to pass through. The upper end area of ​​the pressure cap is larger than the lower end area, and the upper end has symmetrically opened screw holes for easy fixed connection with the upper valve cover 60. The lower end area is adapted to the upper end of the pressure ring for easy compression of the packing 80; the actuator 5 is connected to the upper valve cover 60 by screws, and the valve stem 4 passes through the packing sealing assembly 8 and is connected to the actuator 5.

[0039] In this embodiment of the present invention, the valve seat 2 includes a central support core 20, a valve seat covering outer layer 21, and a hollow elastic metal ring 22. The valve seat covering outer layer 21 is disposed on the outer periphery of the hollow elastic metal ring 22. During the valve closing process, the valve core 3 moves downward and gradually comes into contact with the valve seat 2. The hollow elastic metal ring 22 and the valve seat covering outer layer 21 deform when the valve core 3 comes into contact with the valve seat 2, so that the valve core 3 and the valve seat 2 are in closer contact, and the sealing performance is stronger after the valve is fully closed.

[0040] In this embodiment of the present invention, the valve core 3 further includes a first conical surface 31 and a second conical surface 32. During the valve closing process, if the valve stem 4 deviates when moving downward along the axial direction, when the valve core 3 contacts the valve seat 2, the second conical surface 32 preferentially abuts against the valve seat 2, which can guide the valve stem 4 to move downward along the axial direction normally; then the first conical surface 31 contacts the valve seat covering outer layer 21 of the valve seat 3 and squeezes against each other until the valve is completely closed.

[0041] Specific implementation process: During valve closing, the actuator 5 drives the valve stem 4 to move downward along the axial direction, causing the valve core 3 to gradually approach and abut against the valve seat 2 until the valve is completely closed, completely blocking the medium at the pilot valve port. The PTFE bellows 7 is stretched under the action of the valve stem 4, compressing the valve cavity space and discharging the remaining medium. When the valve is opened, the actuator 5 drives the valve stem 4 to move upward along the axial direction, the valve core 3 separates from the valve seat 2 until the valve is fully open, the hollow elastic metal ring 22 and the outer layer 21 covering the valve seat gradually return to their initial state, the PTFE bellows 7 gradually retracts, and the valve cavity space gradually increases, which is conducive to the flow of the medium and completely blocks the medium in the valve cavity, preventing the medium from flowing into the actuator 5 due to the movement of the valve stem 4. After the valve has been working for a long time, the PTFE bellows 7 may be damaged due to its own wear and aging or due to particles in the medium. At this time, the packing seal assembly 8 can play the role of a second seal, blocking the medium and preventing the medium from leaking out or flowing into the actuator.

[0042] The actuator 5 is existing technology and can be a pneumatic actuator, electric actuator, or other drive device, which can be directly purchased by those skilled in the art and will not be described in detail here.

[0043] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A multi-layer fluoropolymer-lined bellows regulating valve, comprising a valve body (1), a valve seat (2), a valve core (3), a valve stem (4), an actuator (5), a valve cover (6), and a packing seal assembly (8), wherein the valve body (1) is connected to the valve cover (6) to form a valve cavity, the valve seat (2) is fixed inside the valve body (1), the valve stem (4) passes through the valve cover (6) such that one end is located inside the valve cavity and connected to the valve core (3), and the other end is located above the valve cavity and connected to the actuator (5), the actuator (5) drives the valve stem (4) to slide axially, characterized in that: The valve seat (2) includes a central support core (20) and a valve seat covering outer layer (21). The upper end of the central support core (20) is provided with a groove (201). A hollow elastic metal ring (22) is fixed in the groove (201). The valve seat covering outer layer (21) covers the outer periphery of the valve seat body formed by the connection of the central support core (20) and the hollow elastic metal ring (22). The valve seat covering outer layer (21) is made of elastic fluoroplastic material.

2. The multi-layer fluoropolymer-lined bellows regulating valve according to claim 1, characterized in that: The hollow elastic metal ring (22) has a circular cross-section, and the groove (201) has a semi-circular cross-section that is adapted to the outer diameter of the hollow elastic metal ring (22). The hollow elastic metal ring (22) is fixedly connected to the contact surface of the central support core (20).

3. The multi-layer fluoropolymer-lined bellows regulating valve according to claim 1, characterized in that: A fitting groove is formed on the lower outer periphery of the valve seat (2), and a limiting step ring is provided inside the valve body (1). The fitting groove and the limiting step ring are inserted and fitted together, and a sealing ring (9) is provided between the two.

4. The multi-layer fluoropolymer-lined bellows regulating valve according to claim 1, characterized in that: The valve core (3) includes a first conical surface (31) and a second conical surface (32). The first conical surface (31) abuts against the outer layer (21) of the valve seat, causing the outer layer (21) of the valve seat to deform and the two to contact more closely. The second conical surface (32) is located on the lower side of the valve core (3) and can be inserted into the valve seat (2).

5. A multi-layer fluoropolymer-lined bellows regulating valve according to claim 1, characterized in that: It also includes a PTFE bellows (7) sleeved outside the valve stem (4) and a packing seal assembly (8) fixed between the valve cover (6) and the valve stem (4), the packing seal assembly (8) being disposed above the PTFE bellows (7).

6. A multi-layer fluoropolymer-lined bellows regulating valve according to claim 5, characterized in that: The valve cover (6) includes an upper valve cover (60) and a lower valve cover (61). The upper end of the PTFE bellows (7) is sandwiched between the upper valve cover (60) and the lower valve cover (61), and the lower end is fixedly connected to the outer periphery of the valve stem (4). A first sealing ring (62) and a second sealing ring (63) are respectively provided between the upper end of the PTFE bellows (7) and the upper valve cover (60) and the lower valve cover (61).

7. A multi-layer fluoropolymer-lined bellows regulating valve according to claim 6, characterized in that: The packing sealing assembly (8) includes packing (80), pressure ring (81) and pressure cap (82). The packing (80) is disposed in the stuffing box of the upper valve cover (60) and closely attached to the outer periphery of the valve stem. The packing (80) is flexible and has an annular groove that allows the pressure ring (81) to extend into. The upper end area of ​​the pressure cap (82) is larger than the lower end area. The upper end opening can be fixedly connected to the upper valve cover (60), and the lower end is adapted to the pressure ring (81).

8. A multi-layer fluoropolymer-lined bellows regulating valve according to claim 7, characterized in that: The lower section of the pressure ring (81) has a structure that is wider at the top and narrower at the bottom.

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