Pilot-operated type pressure balance pneumatic valve

Abstract

The utility model relates to a pilot-operated type pressure balance pneumatic valve which comprises a valve body, a valve cover and a valve rod, and a valve seat is installed at the position of a valve shoulder of the valve body. The valve body is connected with the valve cover through a bolt; a through hole is formed in the center of the valve deck, the valve rod moves up and down along the through hole in the valve deck, and a sleeve is arranged on the upper portion of the valve seat and fixed in the valve body through the valve deck. A valve clack is arranged in the sleeve and moves up and down in the sleeve; a pilot valve core is arranged in the valve clack; a pressure balance disc is arranged on the top of the pilot valve element. The thrust requirements of the valve in the opening, closing, opening process, closing process and semi-opening state are greatly reduced, the opening process and the closing process only need to overcome friction of all parts and can be achieved without overcoming medium pressure, and meanwhile the medium auxiliary sealing effect in the full-closing state of the valve is reserved; while the good sealing performance is met, the opening and closing thrust of the valve is reduced, the operability of the valve is improved, and the requirement for an actuator is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of ball valve technology, specifically relating to a pilot-operated pressure-balanced pneumatic valve. Background Technology

[0002] In recent years, my country's petrochemical industry has developed rapidly, and pipeline diameters and pressures have also increased accordingly. Gate valves and regulating valves installed on such pipelines, due to the high pressure of the pipeline medium, generally adopt a "high-in, low-out" installation method to achieve effective valve sealing. That is, the pipeline medium enters from the upper end of the valve seat of the gate valve or regulating valve and flows out from the lower end, utilizing the medium pressure acting on the valve disc to assist in valve sealing. At the same time, to reduce the valve opening pressure, a double-disc structure is used: the smaller valve disc opens first to reduce the pressure difference before the larger valve disc opens. However, this structure can only reduce the valve opening thrust to a certain extent. When the valve opens, some pipeline medium pressure still acts on the valve disc. Furthermore, when the valve closes, the high-pressure medium pressure acts directly on the valve disc, which may cause the valve disc to directly impact the valve seat, leading to problems with the regulating valve's inability to accurately adjust the opening.

[0003] For example, Chinese utility model patents with publication numbers CN 210566267 U and CN 214578887 U, used in the field of normal temperature and low temperature high pressure shut-off valves, both employ a double-valve-disc structure to reduce the thrust or torque during valve opening. They utilize the priority opening of the smaller valve disc to reduce the pressure difference across the valve, thereby reducing the medium pressure acting on the larger valve disc. These patents also include balancing holes or pressure relief holes to further reduce the opening thrust of the smaller valve disc. However, these structures can only reduce, but cannot completely eliminate, the valve opening and closing torque caused by medium pressure; the thrust required for valve opening and closing remains relatively large.

[0004] In addition, in existing technical solutions, the valve discs of gate valves and regulating valves lack effective guidance, and the valves are in an active state during operation, which easily leads to vibration and wear. Summary of the Invention

[0005] To address the problems existing in the prior art, this utility model proposes a pilot-operated pressure-balanced pneumatic valve. By designing a sleeve, pilot valve core, and pressure balance disc, the thrust requirements of the valve during opening, closing, the opening process, the closing process, and the half-open state are significantly reduced. The opening and closing processes only need to overcome the friction of the various components, without overcoming the medium pressure, while retaining the medium-assisted sealing effect when the valve is fully closed.

[0006] This utility model proposes a pilot-operated pressure-balanced pneumatic valve, comprising a valve body, a valve cover, and a valve stem. The valve body adopts a top-inlet design, and a valve seat is installed inside the valve cavity (i.e., at the valve shoulder). The valve body and the valve cover are connected together by bolts. A through hole is opened in the center of the valve cover, and the valve stem moves up and down along the through hole on the valve cover to realize the opening and closing operation of the valve. A sleeve is provided on the upper part of the valve seat, and the sleeve is fixed to the valve body by the valve cover. A valve disc is provided inside the sleeve, and the valve disc moves up and down in the sleeve to realize the opening and closing of the main channel of the valve. The flow area between the valve disc and the sleeve can also be adjusted by adjusting the opening height of the valve disc to meet the flow regulation requirements of the valve. A pilot valve core is provided inside the valve disc. A pressure balance disc is provided on the top of the pilot valve core. The thrust requirements of the valve in the opening, closing, opening process, closing process, and half-open state are significantly reduced. The opening and closing processes only need to overcome the friction of the various components, without overcoming the medium pressure, while retaining the medium-assisted sealing effect in the fully closed state of the valve.

[0007] The pilot-operated pressure-balanced pneumatic valve of this invention reduces the thrust required to open and close the valve while maintaining good sealing performance, thereby improving the operability of the valve and reducing the need for actuators.

[0008] In any of the above embodiments, it is preferred that a spring is provided between the pilot valve core and the valve disc, and the spring is selected as a cylindrical helical spring or a disc spring assembly. When the spring is kept in a certain compressed state, the pilot valve core is opened first when the valve is opened, and the pilot valve core is closed last when the valve is closed, thereby reducing the thrust required when the valve is opened and closed.

[0009] The cross-sectional area of ​​the lower end of the pilot valve core is the same as or slightly smaller than the cross-sectional area of ​​the lower end of the valve stem. In this way, when the valve is open or closed, the medium force on the upper end of the pilot valve core can be basically consistent with the resultant force of the medium force on the lower end and the spring. This ensures that the pilot valve core is basically unaffected by the medium pressure during the opening and closing process.

[0010] In any of the above embodiments, it is preferred that the pressure balance disc is connected to the valve disc by bolts.

[0011] In any of the above embodiments, it is preferred that the outer side of the valve disc is provided with a guide groove, which can guide the valve disc during its up and down movement and prevent the valve disc from rotating and vibrating during the valve opening and closing process, thereby improving the stability of valve operation.

[0012] In any of the above embodiments, it is preferred that the pilot valve core has a through hole corresponding to the opening on the pressure balance disc. The opening on the pressure balance disc and the through hole on the pilot valve core achieve pressure balance between the valve chamber and the downstream of the valve.

[0013] In any of the above embodiments, it is preferred that a flexible graphite gasket is provided between the valve body and the valve cover to achieve a sealing effect.

[0014] In any of the above embodiments, it is preferred that a packing assembly is provided between the valve stem and the valve cover to achieve a sealing effect, and the external seal of the valve has good fire resistance.

[0015] In any of the above embodiments, preferably, a graphite gasket is provided between the valve seat and the valve body to achieve a seal; the sealing surface of the valve seat is hardened to increase the valve's wear resistance, enabling it to withstand high pressure while also possessing fire-resistant properties. The inner wall of the sleeve is hardened and sprayed to reduce friction on the valve disc and also provide good guiding properties.

[0016] In any of the above embodiments, preferably, the lower end of the sleeve has a window for media flow, and the total area of ​​the window is larger than the area of ​​the pipes before and after the valve to facilitate smooth media flow. The upper part of the sleeve has multiple pressure balancing holes for balancing the media pressure inside the valve cavity and upstream and downstream of the valve. The total area of ​​the pressure balancing holes is larger than the channel area of ​​the valve disc to balance the media pressure inside the valve cavity and upstream and downstream of the valve. The shape of the window at the lower end of the sleeve can be changed as needed to control the valve flow rate regulation curve, such as rectangular, U-shaped, rhomboid, elliptical, etc.

[0017] In any of the above embodiments, it is preferred that the top of the valve cover is provided with an actuator bracket and a pneumatic actuator, and the actuator bracket is provided with a valve on / off indicator to indicate the valve's on / off status and opening degree; the pneumatic actuator is selected from a pneumatic diaphragm structure or a cylinder structure. Alternatively, replacing the pneumatic actuator with a manual gear operating mechanism or an electric operating mechanism can also achieve valve opening and closing with a smaller thrust.

[0018] In summary, the pilot-operated pressure-balanced pneumatic valve of this utility model has the following advantages: the design of the sleeve, pilot valve core, and pressure balance disc significantly reduces the thrust requirements of the valve during opening, closing, the opening process, the closing process, and the half-open state. The opening and closing processes only require overcoming the friction of the components, without needing to overcome the medium pressure, while retaining the medium-assisted sealing effect in the fully closed state. The sealing contact parts of the valve seat, pilot valve core, and valve disc are all hardened, enabling them to withstand high pressure and providing fire resistance. The inner wall of the sleeve is hardened and sprayed, reducing friction on the valve disc and providing good guidance. Replacing the pneumatic actuator with a manual gear operating mechanism or an electric operating mechanism can also achieve pressure-balanced switching. By changing the shape of the window at the lower end of the sleeve, the adjustment defects of quick-opening, equal percentage, and linear characteristics can be addressed, thus realizing the function of a regulating valve.

[0019] Explanation of icon numbers

[0020] Valve body 1, valve cover graphite gasket 2, valve cover 3, valve stem 4, packing assembly 5, actuator bracket 6, valve on / off indicator 7, actuator 8, valve seat graphite gasket 9, valve seat 10, sleeve 11, pressure balance hole 111, window 112, valve disc 12, spring 13, pilot valve core 14, through hole 141, pressure balance disc 15, opening 151, valve cavity 16. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a preferred embodiment of the pilot-operated pressure-balanced pneumatic valve according to the present invention.

[0022] Figure 2 In accordance with the present invention, the pilot-operated pressure-balanced pneumatic valve Figure 1 The diagram shows the valve in the fully open state in the preferred embodiment.

[0023] Figure 3 In accordance with the present invention, the pilot-operated pressure-balanced pneumatic valve Figure 1 The diagram shows the valve in the fully closed state in the preferred embodiment.

[0024] Figure 4 In accordance with the present invention, the pilot-operated pressure-balanced pneumatic valve Figure 1 A schematic diagram of the internal structure of the valve cavity in the preferred embodiment is shown.

[0025] Figure 5 In accordance with the present invention, the pilot-operated pressure-balanced pneumatic valve Figure 1 The diagram shows a structural schematic of the sleeve in the preferred embodiment.

[0026] Figure 6 In accordance with the present invention, the pilot-operated pressure-balanced pneumatic valve Figure 1 The diagram shows a structural schematic of the pressure balance disc in the preferred embodiment. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] like Figure 1The diagram shown is a structural schematic of a preferred embodiment of the pilot-operated pressure-balanced pneumatic valve of this utility model. The purpose of this utility model is to provide a pilot-operated pressure-balanced pneumatic valve, comprising a valve body 1, a valve cover 3, and a valve stem 4. The valve body 1 adopts a top inlet design, and a valve seat 10 is installed in the valve cavity 16 (i.e., at the valve shoulder) of the valve body 1. The valve body 1 and the valve cover 3 are connected together by bolts. A through hole is opened in the center of the valve cover 3, and the valve stem 4 moves up and down along the through hole on the valve cover 3 to realize the opening and closing operation of the valve. A sleeve 11 is provided on the upper part of the valve seat 10, and the sleeve 11 is fixed inside the valve body 1 by the valve cover 3. A valve disc 12 is provided inside the sleeve 11, and the valve disc 12 moves up and down within the sleeve 11 to realize the opening and closing of the main channel of the valve. The flow area between the valve disc 12 and the sleeve 11 can also be adjusted by adjusting the opening height of the valve disc 12 to meet the flow regulation requirements of the valve. A pilot valve core 14 is provided inside the valve disc 12. A pressure balance disc 15 is provided on the top of the pilot valve core 14. The thrust requirements of the valve are significantly reduced during opening, closing, opening process, closing process, and half-open state. The opening and closing processes only need to overcome the friction of the various components, without overcoming the medium pressure, while retaining the medium-assisted sealing effect when the valve is fully closed.

[0029] The pilot-operated pressure-balanced pneumatic valve of this invention reduces the thrust required to open and close the valve while maintaining good sealing performance, thereby improving the operability of the valve and reducing the need for actuators.

[0030] In this embodiment, the top of the valve cover 3 is provided with an actuator bracket 6 and a pneumatic actuator 8. The actuator bracket 6 is provided with a valve on / off indicator 7 to indicate the valve's on / off status and opening degree. The pneumatic actuator 8 is selected from a pneumatic diaphragm structure or a cylinder structure. In addition, the pneumatic actuator 8 can be replaced with a manual gear operating mechanism or an electric operating mechanism to achieve valve opening and closing with a smaller thrust.

[0031] See Figure 2 As shown, in the pilot-operated pressure-balanced pneumatic valve of this utility model... Figure 1 The diagram shows the valve in the fully open state in the preferred embodiment.

[0032] When the valve is fully or partially open, the medium can also achieve pressure balance at both ends of the valve disc 12 through the openings on the sleeve 11, the pressure balance disc 15, and the pilot valve core 14, so that the valve disc 12 is not affected by the medium pressure. In particular, it improves the stability of the valve stem 4 when the valve is half open and reduces the demand for actuator thrust when the valve is sealed.

[0033] Please refer to the following: Figure 3 As shown, in the pilot-operated pressure-balanced pneumatic valve of this utility model... Figure 1 The diagram shows the valve in the fully closed state in the preferred embodiment.

[0034] When the valve is fully closed, the upstream medium can enter the valve chamber through the pressure balance hole set at the top of the sleeve 11, so that the medium pressure in the valve chamber is consistent with the upstream pipeline pressure. The medium slowly enters the valve disc 12 from the opening of the pressure balance plate 15 and the hole of the pilot valve core 14, so that the medium pressure acts on the valve disc 12, realizing the medium pressure-assisted sealing function and reducing the demand on the actuator thrust when the valve is sealed.

[0035] When the valve opens from the closed state, the actuator 8 drives the valve stem 4 to move upward. Under the action of the spring 13, the pilot valve core 14 opens preferentially over the valve disc 12. Due to the hole at the top of the sleeve and the opening of the pressure balance plate 15, the pilot valve core 14 is almost unaffected by the medium pressure. The opening of the pilot valve core 14 only requires overcoming the friction of the valve stem 4 and the friction of the packing. After the pilot valve core 14 opens, the medium in the valve cavity can quickly flow to the downstream of the valve through the channel between the pilot valve core 14 and the valve disc 12. Since the opening at the top of the sleeve 11 is much smaller than the channel area of ​​the valve disc 12, the medium in the valve cavity cannot be replenished in time, so that the medium pressure at both ends of the valve disc 12 is balanced and consistent with the downstream pipeline. The valve disc 12 is no longer affected by the pipeline medium pressure. At this time, opening the valve disc 12 only requires overcoming the friction between the valve disc 12 and the sleeve 11. After the valve disc 12 is opened, the upstream pipeline medium is connected to the downstream medium, and at the same time, it is connected to the valve cavity through the opening of the pilot valve core 14 and the pressure balance plate 15, so as to achieve the medium pressure balance at the upper and lower ends of the valve disc 12 again.

[0036] When the valve closes from the open state, the actuator drives the valve stem 4 downward. Under the action of the spring 13, the valve disc 12 closes preferentially over the pilot valve core 14. Since the medium pressure at both ends of the valve disc 12 is balanced, the closing of the valve disc 12 is not affected by the medium pressure. The closing process only needs to overcome the friction between the valve disc 12 and the sleeve 11. After the valve disc 12 closes, the valve cavity is connected to the upstream medium only through the small hole at the top of the sleeve 11. However, the valve cavity is connected to the downstream through the pressure balance hole and the channel between the pilot valve core 14 and the valve disc 12. Since the area of ​​the small hole at the top of the sleeve 11 is much smaller than the area of ​​the channel between the pilot valve core 14 and the valve disc 12, the pressure in the valve cavity quickly becomes consistent with the downstream of the pipeline. At this time, the medium pressure at both ends of the pilot valve core 14 is also balanced. The closing of the pilot valve core 14 only needs to overcome the friction of the valve stem 4 and the friction of the packing.

[0037] See Figure 4 As shown, in the pilot-operated pressure-balanced pneumatic valve of this utility model... Figure 1 A schematic diagram of the internal structure of the valve cavity in the preferred embodiment is shown.

[0038] In this embodiment, a valve seat 10 is provided in the valve cavity, and a sleeve 11 is provided on the upper part. The sleeve 11 is fixed in the valve body 1 by the valve cover 3. A valve disc 12 is provided inside the sleeve 11, and the valve disc 12 moves up and down in the sleeve 11. A pilot valve core 14 is provided inside the valve disc 12. A pressure balance plate 15 is provided on the top of the pilot valve core 14.

[0039] In this embodiment, a spring 13 is provided between the pilot valve core 14 and the valve disc 12. The spring 13 is selected as a cylindrical helical spring or a disc spring assembly. When the spring 13 is kept in a certain compressed state, the pilot valve core 14 is opened first when the valve is opened, and the pilot valve core is closed last when the valve is closed, thereby reducing the thrust required when the valve is opened and closed.

[0040] The cross-sectional area of ​​the lower end of the pilot valve core 14 is consistent with or slightly smaller than the cross-sectional area of ​​the lower end of the valve stem 4. In this way, when the valve is open or closed, the medium force borne by the upper end of the pilot valve core 14 can be basically consistent with the resultant force of the medium force borne by the lower end and the spring 13. This ensures that the pilot valve core 14 is basically unaffected by the medium pressure during the opening and closing process.

[0041] In this embodiment, the pressure balance plate 15 is connected to the valve disc 12 by bolts.

[0042] In this embodiment, the outer side of the valve disc 12 is provided with a guide groove 121, which can guide the valve disc 12 during its up and down movement and prevent the valve disc from rotating and vibrating during the valve opening and closing process, thereby improving the stability of valve operation.

[0043] In this embodiment, a flexible graphite gasket 2 is provided between the valve body 1 and the valve cover 3, thereby playing a sealing role.

[0044] In this embodiment, a packing assembly 5 is provided between the valve stem 4 and the valve cover 3 to achieve a sealing function, and the external seal of the valve has good fire resistance.

[0045] In this embodiment, a graphite gasket 9 is provided between the valve seat 10 and the valve body 1 to achieve a seal; the sealing surface of the valve seat 10 is hardened to increase the wear resistance of the valve, enabling it to withstand high pressure while also possessing fire-resistant properties. The inner wall of the sleeve 11 is hardened and sprayed to reduce friction on the valve disc 12 and also to provide good guidance.

[0046] like Figure 5 As shown, in the pilot-operated pressure-balanced pneumatic valve of this utility model... Figure 1 The diagram shows a structural schematic of the sleeve in the preferred embodiment.

[0047] In this embodiment, the lower end of the sleeve 11 has a window 112 for media flow. The total area of ​​the window 112 is larger than the area of ​​the pipes before and after the valve, facilitating smooth media flow. The upper part of the sleeve 11 has multiple pressure balancing holes 111 for balancing the media pressure in the valve cavity 16 and upstream and downstream of the valve. The total area of ​​the pressure balancing holes 111 is larger than the channel area of ​​the valve disc 12. The shape of the window 112 at the lower end of the sleeve 11 can be changed as needed to control the valve flow rate regulation curve, such as rectangular, U-shaped, rhomboid, elliptical, etc.

[0048] See last for reference. Figure 6 As shown, in the pilot-operated pressure-balanced pneumatic valve of this utility model... Figure 1 The diagram shows a structural schematic of the pressure balance disc in the preferred embodiment.

[0049] In this embodiment, the pilot valve core 14 has a through hole 141 corresponding to the opening 151 on the pressure balance disc 15. The opening 151 on the pressure balance disc 15 and the through hole 141 on the pilot valve core 14 achieve pressure balance between the valve chamber 16 and the downstream of the valve.

[0050] The total area of ​​the openings 151 on the pressure balance disc 15 should be basically consistent with the total area of ​​the through holes 141 on the pilot valve core 14, and slightly larger than the channel area between the pilot valve core 14 and the valve disc 12. The cross-sectional area of ​​the valve stem 4 inside the valve cavity should be slightly larger than the sealing cross-sectional area of ​​the pilot valve core 12 to ensure that the sum of the medium pressure and the spring thrust 13 borne by the lower end of the pilot valve core 14 is equal to the medium pressure borne by the upper end of the pilot valve core 14, so that the total force on the pilot valve core 1 is minimized when it is opened and closed.

[0051] It will be readily understood by those skilled in the art that the pilot-operated pressure-balanced pneumatic valve of this utility model comprises any combination of the parts described in this specification. Due to space limitations and for the sake of brevity, these combinations are not described in detail here, but after reading this specification, the scope of this utility model, which consists of any combination of the parts constituted in this specification, is self-evident.

Claims

1. A pilot-operated pressure-balanced pneumatic valve, comprising a valve body (1), a valve cover (3), and a valve stem (4), wherein the valve body (1) adopts a top inlet design, and a valve seat (10) is installed in the valve cavity (16) of the valve body (1); the valve body (1) and the valve cover (3) are connected together by bolts; a through hole is opened in the center of the valve cover (3), and the valve stem (4) moves up and down along the through hole on the valve cover (3), characterized in that: A sleeve (11) is provided on the upper part of the valve seat (10), and the sleeve (11) is fixed in the valve body (1) by the valve cover (3); a valve disc (12) is provided inside the sleeve (11), and the valve disc (12) moves up and down in the sleeve (11); a pilot valve core (14) is provided inside the valve disc (12); a pressure balance plate (15) is provided on the top of the pilot valve core (14).

2. The pilot-operated pressure-balanced pneumatic valve as described in claim 1, characterized in that: A spring (13) is provided between the pilot valve core (14) and the valve disc (12). The spring (13) is a cylindrical helical spring or a disc spring assembly.

3. The pilot-operated pressure-balanced pneumatic valve as described in claim 1, characterized in that: The pressure balance plate (15) is connected to the valve disc (12) by bolts.

4. The pilot-operated pressure-balanced pneumatic valve as described in claim 1 or 2, characterized in that: The valve disc (12) has a guide groove (121) on its outer side.

5. The pilot-operated pressure-balanced pneumatic valve as described in claim 1, characterized in that: The pilot valve core (14) has a through hole (141) that corresponds to the opening (151) on the pressure balance plate (15).

6. The pilot-operated pressure-balanced pneumatic valve as described in claim 1, characterized in that: A flexible graphite pad (2) is provided between the valve body (1) and the valve cover (3).

7. The pilot-operated pressure-balanced pneumatic valve as described in claim 1, characterized in that: A packing assembly (5) is provided between the valve stem (4) and the valve cover (3).

8. The pilot-operated pressure-balanced pneumatic valve as described in claim 1, characterized in that: A graphite gasket (9) is provided between the valve seat (10) and the valve body (1) to achieve sealing; the sealing surface of the valve seat (10) is hardened.

9. The pilot-operated pressure-balanced pneumatic valve as described in claim 1 or 4, characterized in that: The lower end of the sleeve (11) has a window (112), the total area of ​​which is greater than the area of ​​the pipes before and after the valve; the upper part of the sleeve (11) has multiple pressure balancing holes (111), the total area of ​​which is greater than the channel area of ​​the valve disc (12).

10. The pilot-operated pressure-balanced pneumatic valve as described in claim 1, characterized in that: The top of the valve cover (3) is provided with an actuator bracket (6) and a pneumatic actuator (8). The actuator bracket (6) is provided with a valve switch indicator (7). The pneumatic actuator (8) is selected from pneumatic diaphragm structure or cylinder structure.

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