A four-stage cage-type regulating valve

Abstract

This invention relates to a four-stage cage-type regulating valve, comprising a valve body, a valve seat, a valve core, a valve stem, a pressure-reducing sleeve, and an upper valve cover. The upper valve cover is located above the valve body, and the valve seat is installed inside the valve body. The valve stem and valve core are installed inside the valve seat and connected by threads. The pressure-reducing sleeve is located on the upper periphery of the valve seat, and the upper space of the valve core and the pressure-reducing sleeve forms a balanced space. The technical solution provided by this invention is based on the multi-stage pressure reduction principle and a balanced structure. By drilling holes in the valve core, valve seat, and pressure-reducing sleeve, the fluid pressure can be reduced step by step. Combined with the meandering reciprocating flow channel, cavitation and flashing phenomena caused by high pressure differentials are prevented, thus preventing damage to the equipment and improving the service life of the regulating valve.

Description

Technical Field

[0001] This invention relates to the field of valves, and more particularly to a four-stage cage control valve. Background Technology

[0002] In the petrochemical, pressure and heating industries, with technological advancements and progress in metallurgical refining, high-pressure differential and strong cavitation conditions are becoming increasingly common, leading to the widespread use of high-pressure regulating valves, especially in applications requiring high pressure differential and cavitation resistance. For high-pressure gas or liquid media, relying solely on single-stage pressure reduction supplemented by noise-reducing plates is insufficient to effectively address the critical tasks of pressure reduction and noise reduction. When the downstream pressure falls below the saturated vapor pressure of the medium, flash evaporation occurs, severely damaging the valve internals. This necessitates a multi-stage pressure-reducing valve core. The porous valve core of this invention disperses the medium into several small jets, which intersect, causing energy to cancel each other out. Combined with a meandering flow path, this reduces erosion damage to the valve internals, lowers noise from gas impacts, enhances the pressure reduction and deceleration effect, and extends the service life of the regulating valve. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a four-stage cage-type regulating valve that overcomes or at least partially solves the above problems. The four-stage cage-type regulating valve includes: a valve body 1, a valve seat 2, a valve core 5, a valve stem 13, a pressure-reducing sleeve 6, and an upper valve cover 9;

[0004] The upper valve cover 9 is located above the valve body 1. A valve seat 2 is installed inside the valve body 1. The valve seat 2 is an upward-opening cavity. A valve stem 13 and a valve core 5 are installed inside the valve seat 2. The two are connected by threads. The valve core 5 is a cavity with openings at both the upper and lower ends. It is inserted and installed on the valve seat 2. The lower part of the valve core 5 is located inside the valve seat 2, and the upper part of the valve core 5 is located above the valve seat 2. The pressure reducing sleeve 6 includes an integrally welded pressure reducing outer cylinder 62 and pressure reducing inner cylinder 61. The pressure reducing sleeve 6 is located on the upper periphery of the valve seat 2.

[0005] Furthermore, a platform-shaped protrusion is formed at the transition point from the lower part to the upper part of the valve core, and the platform-shaped protrusion is engaged on the valve seat 2.

[0006] Furthermore, various sealing gaskets 14 are provided at the connection between the valve body 1, the upper sleeve, and the valve seat 2.

[0007] Furthermore, the upper valve cover 9 and the valve body 1 are connected by bolt fasteners 10.

[0008] Furthermore, the top of the upper valve cover 9 is provided with a groove, and the groove is filled with packing material 11.

[0009] Furthermore, a packing fixing assembly 12 is provided in the groove, and the valve stem 13 passes through the groove and the packing fixing assembly 12.

[0010] Furthermore, the valve stem 13 is located at the center of the regulating valve and extends through the entire valve body.

[0011] Furthermore, the guide sleeve 7 is provided between the bottom end of the upper valve cover 9 and the valve stem 13.

[0012] Furthermore, the upper space of the valve core 5 and the pressure reducing sleeve 6 forms a balance space 804; the pressure reducing inner cylinder 61, the valve core 5, the upper valve cover 9, the balance piston ring 8, the valve stem 13 and the balance space 804 constitute a balanced structure; the fluid in the fluid passage achieves fluid pressure balance between the upper part and the lower part of the valve core 5 in the balance space 804, realizing the function of the balanced structure.

[0013] Furthermore, the bolt fastener 10 is a double-ended bolt and a nut.

[0014] The technical solution provided by this invention is based on the principle of multi-stage pressure reduction and a balanced structure. By drilling holes in the valve core, valve seat, and pressure-reducing sleeve, the fluid pressure can be reduced step by step. Combined with a meandering flow channel, this prevents cavitation and flashing phenomena caused by high pressure differentials, thus preventing damage to the equipment and extending the service life of the regulating valve. Furthermore, based on a stroke-scientific calculation-based drilling method, the number of holes is determined in stages to set the shape of the through-holes, achieving the effect of pressure reduction and flow diversion.

[0015] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the assembly structure of the four-stage cage-type regulating valve of the present invention in the closed state;

[0018] Figure 2 This is a schematic diagram of the flow direction of the four-stage cage-type regulating valve of the present invention at 50% of its stroke.

[0019] Figure 3 This is a cross-sectional view of the pressure-reducing sleeve of the present invention;

[0020] Figure 4 for Figure 1 A magnified view of a portion of the image;

[0021] Figure 5 This is a schematic diagram illustrating an example of a through-hole configuration.

[0022] Explanation of reference numerals in the attached figures:

[0023] 1-Valve body, 2-Valve seat, 3-Locking nut, 4-Anti-rotation steel ball, 5-Valve core, 6-Pressure reducing sleeve, 61-Pressure reducing inner cylinder, 62-Pressure reducing outer cylinder, 7-Guide sleeve, 8-Balance piston ring, 9-Upper valve cover, 10-Bolt fastener, 11-Packing, 12-Packing fixing assembly, 13-Valve stem, 14-Multiple sealing gaskets. Detailed Implementation

[0024] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0025] The terms "comprising" and "having," and any variations thereof, in the specification, embodiments, claims, and drawings of this invention are intended to cover non-exclusive inclusion, such as including a series of steps or units.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0027] like Figure 1-3 This invention provides a four-stage cage-type regulating valve, comprising a valve body 1, a valve seat 2, a valve core 5, a valve stem 13, a pressure-reducing sleeve 6, and an upper valve cover 9.

[0028] The upper valve cover 9 is located above the valve body 1. The valve body 1 is equipped with a valve seat 2, which is an upward-opening cavity. The valve seat 2 is equipped with a valve stem 13 and a valve core 5, which are connected by threads. The valve core 5 is an upward-opening and downward-opening cavity; it is inserted and installed on the valve seat 2. The lower part of the valve core 2 is located inside the valve seat 2, and the upper part of the valve core 2 is located above the valve seat 2. The pressure reducing sleeve 6 is sleeved on the outer side of the upper part of the valve core 2.

[0029] Preferably, a table-shaped protrusion is formed at the transition point from the lower part to the upper part of the valve core, and the table-shaped protrusion is engaged on the valve seat 2; as the stroke progresses, the protrusion moves away from the valve seat, and is engaged on the valve seat at the 0 stroke position;

[0030] Preferably, the pressure-reducing sleeve 6 includes an integrally welded pressure-reducing outer sleeve 62 and a pressure-reducing inner sleeve 61; the lower space between the valve core 5 and the valve seat 2 forms a first buffer space 801, the space between the outer side of the valve core 5 and the pressure-reducing inner sleeve 61 forms a second buffer space 802, the space between the pressure-reducing inner sleeve 61 and the pressure-reducing outer sleeve 62 forms a third buffer space 803, and the upper space between the valve core 5 and the pressure-reducing sleeve 6 forms a balance space 804.

[0031] As attached Figure 1 As shown in Figure 2, after the valve is opened, the flow direction of the fluid in the fluid passage passes through the lower throttling orifice of the valve seat 2 and the lower part of the valve core 5 in sequence, and flows into the first buffer space 801. This stage is the first stage of pressure reduction. Then it flows through the lower part of the throttling orifice of the valve core 5 and flows into the second buffer space 802. This stage is the second stage of pressure reduction. Next, it flows through the throttling orifice of the pressure-reducing inner cylinder 61, the outer side of the pressure-reducing inner cylinder 61, the throttling window of the pressure-reducing inner cylinder 61, and the upper outer side of the valve core 5, and flows into the third buffer space 803. This stage is the third stage of pressure reduction. Finally, it flows through the upper throttling orifice of the pressure-reducing sleeve 6, passes through the pressure-reducing sleeve 6, and flows into the valve body 1. This stage is the fourth stage of pressure reduction.

[0032] To accommodate the aforementioned pressure reduction direction, windows and through holes are provided on the pressure reduction sleeve. Specifically, a window is provided on the upper part of the pressure reduction inner cylinder 61, and a first circular through hole combination is provided on its lower part. A second circular through hole combination is provided on the upper part of the pressure reduction sleeve, that is, the upper part of the cavity. No openings are provided on the corresponding parts of the pressure reduction outer cylinder and the pressure reduction inner cylinder. Here, the window size is much larger than the area of ​​a single circular through hole.

[0033] After the fluid medium leaves the second buffer space and enters the third buffer space, the fluid direction changes by 180 degrees, and the pressure-reducing outer cylinder brings greater pressure. Pressure can be released by setting windows; and the area of ​​windows and through holes can constrain the pressure-reducing effect.

[0034] Preferably, a row of windows is provided, and the first circular through-hole combination includes multiple rows of through-holes, and the total area of ​​the windows is equal to the total area of ​​the circular through-holes;

[0035] Preferably, the upper part of the valve core 5 is provided with a groove for guiding the installation of the balance piston ring 8. The valve core 5 and the valve stem 13 are fixed by a locking nut 3 and equipped with steel balls to prevent rotation. In the fluid passage, the fluid pressure in the upper part and the lower part of the valve core 5 is balanced within the balance space 804, realizing the function of the balanced structure.

[0036] The valve core 5, the lower part of the valve seat 2, and the first buffer space 801 form a first-stage pressure-reducing structure. The lower part of the valve seat 2 and the lower part of the valve core 5 are provided with several throttling orifices for fluid passage. The fluid in the fluid passage regulates the fluid pressure inside and outside the valve seat 2 within the first buffer space 801, thus realizing the function of the first-stage pressure-reducing structure.

[0037] The second-stage pressure-reducing structure consists of the outer side of the valve core 5, the pressure-reducing inner cylinder 61, and the second buffer space 802. The lower part of the pressure-reducing inner cylinder 61 is provided with several throttling orifices and throttling windows for fluid passage. Within the second buffer space 802, the fluid pressure inside and outside the valve core 5 is regulated, thus realizing the function of the second-stage pressure-reducing structure.

[0038] The third-stage pressure-reducing structure consists of the outer side of the valve core 5, the pressure-reducing inner cylinder 61, the pressure-reducing outer cylinder 62, and the third buffer space 803. The upper part of the pressure-reducing inner cylinder 61 is provided with several throttling orifices for fluid passage. In the fluid passage, the fluid pressure inside and outside the pressure-reducing inner cylinder 61 is regulated within the third buffer space 803, thus realizing the function of the third-stage pressure-reducing structure.

[0039] The fourth-stage pressure-reducing structure is formed by the upper part of the pressure-reducing sleeve 6, the outer side of the valve core 5, and the interior of the valve body 1. The upper part of the pressure-reducing sleeve 6 is provided with several throttling orifices for fluid passage. The throttling orifices in the fluid passage realize the regulation of fluid pressure inside and outside the pressure-reducing sleeve 6, thus realizing the function of the fourth-stage pressure-reducing structure.

[0040] A guide sleeve 7 is provided between the bottom end of the upper valve cover 9 and the valve stem 13. The outer side and lower part of the valve core 5 are fitted with the pressure reducing sleeve 6 and the valve seat 2 through clearance, and together with the guide sleeve 7, they complete the guiding function of the components. This multi-guide structure can reduce the vibration when the valve is opened and closed, and reduce the unbalanced force when opening and closing, so that the operation is smooth and easy to control.

[0041] Preferably, multiple sealing gaskets 14 are provided at the connection between the valve body 1, the upper sleeve, and the valve seat 2. This ensures the sealing effect inside the four-stage cage-type regulating valve and prevents internal leakage.

[0042] Preferably, the upper valve cover 9 and the valve body 1 are connected by bolt fasteners 10, for example, by double-ended bolts and nuts.

[0043] Preferably, the top of the upper valve cover 9 is provided with a groove, the groove is filled with packing 11, and a packing fixing assembly 12 is provided in the groove. The valve stem 13 passes through the groove and the packing fixing assembly 12. The packing is a special packing for high-pressure conditions, which can ensure the sealing performance of the packing during operation and prevent valve leakage.

[0044] To maximize the pressure reduction capacity of the pressure-reducing valve, the size and arrangement of the through holes need to be determined while meeting requirements for strength and machining accuracy. A circular through hole is provided on the lower surface of the valve core; for example, circular through holes are provided on both the inner and outer pressure-reducing cylinders. The calculation method for setting the circular through holes includes the following steps:

[0045] Step S1: Initialize the row sequence value; calculate the distance h between the sections based on the control valve section accuracy and total stroke;

[0046] For example: the cross-sectional accuracy of the regulating valve is 10 equal parts, the total stroke is 30mm, and h is 3mm; the higher the number of equal parts, the higher the cross-sectional accuracy;

[0047] Step S2: Calculate the approximate surface window width: Specifically: Determine the number of windows Z corresponding to the current row sequence value; calculate the window width using the following formula;

[0048]

[0049] Where: l k —Window width (cm) within the current cross-section; the cross-section is the area through which the fluid medium can flow when the valve is opened to a height h;

[0050] l k-1 — Window width (cm) within the previous section;

[0051] A k —The opening area of ​​the window within the current cross-section (cm²) 2 );

[0052] Z – Number of windows;

[0053] h — the distance between cross sections (cm);

[0054] A k-1 —Window opening area within the previous section (cm²) 2 );

[0055] In other words, the number of through holes and the stroke height are directly related to their corresponding row sequence. Since the drilling size can be kept accurate through calculation and processing, this invention proposes a method of fixing the number of holes in stages to reduce computational complexity. That is, the number of through holes is changed in stages based on the stroke height, so that the row sequence is divided into different row sequence groups. Multiple row sequences within a group correspond to the same number of through holes, while different row sequence groups correspond to different numbers of through holes. For example, rows 1-5 have 30 through holes, rows 6-10 have 20 through holes, and rows 11-14 are adjusted according to on-site testing.

[0056] Step S3: Derive the window hole radius r; convert the window into a through hole; if the row sequence value is less than the maximum row sequence value, increment the row sequence value and return to step S2; otherwise, end the calculation.

[0057] The derivation of the window drilling radius r; converting the window into a through hole, specifically: converting the window into a circular hole by making the sleeve window area equal to the sleeve hole area; using the following formula for derivation;

[0058]

[0059] Where: r — the radius of the hole (cm);

[0060] Preferred configuration: The through holes are arranged on the surface according to an average distribution method, so that the position of the through holes is positionally related to h; it also includes different sizes of holes and arrangements according to different opening degrees to achieve different opening degree adjustment capabilities. The large hole + small hole method can achieve pressure reduction and flow diversion while ensuring fluid regulation. The pressure impact is evenly distributed from the valve core sealing surface to each small hole through the small hole jet method to achieve the effect of pressure reduction and flow diversion.

[0061] Preferably, the through holes are set using the same calculation method on the upper surface of the valve core, and the gradient direction of the through holes is opposite to that of the lower through holes of the valve core. As the stroke advances, the through holes become larger.

[0062] Taking a 6-inch control valve, based on a pipe diameter of DN150 and the valve flow coefficient, the valve seat inner diameter Dc = 143mm is selected, and the corresponding maximum flow Cv = 246%. The inner orifice data of the sleeve can be calculated using the sleeve window.

[0063]

[0064] The specific calculation of the hole arrangement on the surface for the above example is attached. Figure 5 As shown, the arrangement and size of the through holes are related to the above calculation results. The through holes decrease in size with the direction of fluid flow. After arranging the through holes according to different openings and different hole diameters, the arrangement of the through holes is irregular. That is, the number and size of the through holes are determined first, and then the positions are calculated. The above calculation method can be applied to the drilling design of all shapes and surfaces.

[0065] The surface profiles in the multi-stage pressure reduction process of this invention are all performed using the above-described method. By reducing pressure in multiple stages, the pressure drop of each stage is distributed, thus realizing a multi-stage pressure reduction structure mainly based on a cage-type perforated structure.

[0066] Furthermore, this invention introduces a balanced structure; a balanced pressure-reducing structure is provided in the regulating valve, using the medium to directly control the pressure on both sides of the valve core, passively keeping the valve core in a balanced state; its principle is that due to the existence of liquid pressure, the valve core will move in the direction of the liquid pressure. The balanced structure is passive balancing and has a simple structure. The balanced pressure-reducing structure consists of a pressure-reducing inner cylinder 61, a valve core 5, an upper valve cover 9, a balanced piston ring 8, a valve stem 13, and a balanced space 804, which can reduce unbalanced forces during the opening and closing process;

[0067] To achieve the aforementioned balanced structure, a portion of the medium at the lower part of the valve core is diverted into the balance space 804. Sealing elements such as piston rings ensure the balance space is sealed. The pressure generated by the medium itself pushes the valve core downwards to seal, simultaneously offsetting some of the upward force exerted by the medium pressure at the lower part of the valve core, thus achieving dynamic balance of the valve core. Correspondingly, in the four-stage cage-type control valve, during fluid flow, while undergoing a first-stage pressure reduction, the fluid sequentially passes through the upper part of the valve core 5, the lower part of the valve stem 13, the upper part of the pressure-reducing sleeve 6, the lower part of the upper valve cover 9, and the balance piston ring 8 before flowing into the balance space 804. This stage uses the balanced structure to balance the pressure above and below the valve core 5. Based on the multi-stage pressure reduction principle and the balanced structure, perforations in the valve core, valve seat, and pressure-reducing sleeve allow for progressive pressure reduction of the fluid. Combined with the meandering flow path, this prevents cavitation and flashing phenomena caused by high pressure differentials, thus preventing damage to the equipment and improving the service life of the control valve.

[0068] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A four-stage cage-type regulating valve, characterized in that, include: Valve body (1), valve seat (2), valve core (5), valve stem (13), pressure reducing sleeve (6) and upper valve cover (9); The upper valve cover (9) is located above the valve body (1). A valve seat (2) is installed inside the valve body (1). The valve seat (2) is an upward-opening cavity. A valve stem (13) and a valve core (5) are installed inside the valve seat (2). The two are connected by threads. The valve core (5) is an upward-opening and downward-opening cavity, which is inserted and installed on the valve seat (2). The lower part of the valve core (5) is located inside the valve seat (2), and the upper part of the valve core (5) is located above the valve seat (2). The pressure reducing sleeve (6) includes an integrally welded pressure reducing outer cylinder (62) and pressure reducing inner cylinder (61). The pressure reducing sleeve (6) is located on the upper periphery of the valve seat (2). A circular through hole is provided on the lower surface of the valve core; the number of through holes is changed in stages based on the stroke height, so that the stroke sequence is divided into different stroke sequence groups. The number of through holes is the same for multiple stroke sequences within a group, while the number of through holes is different for different stroke sequence groups; the number of through holes and the stroke height are directly related to their corresponding stroke sequence. The calculation method for setting a circular through hole includes the following steps: Step S1: Initialize the row sequence value; calculate the distance h between the sections based on the control valve section accuracy and total stroke; Step S2: Calculate the approximate surface window width: Specifically: Determine the number of windows Z corresponding to the current row sequence value; calculate the window width using the following formula; Where: l k —Window width (cm) within the current cross-section; the cross-section is the area through which the fluid medium can flow when the valve is opened to a height h; l k-1 —Window width (cm) within the previous section; A k —The opening area of ​​the window within the current cross-section (cm²) 2 Z—Number of windows; h—Distance between sections (cm); A k-1 —Window opening area within the previous section (cm²) 2 ); Step S3: Derive the window hole radius r; convert the window into a through hole; if the row sequence value is less than the maximum row sequence value, increment the row sequence value and return to step S2; otherwise, end the calculation. Derive the window drilling radius r; convert the window into a through hole, specifically by converting the window into a circular hole based on the principle that the area of ​​the sleeve window is equal to the area of ​​the sleeve hole; the following formula is used for derivation; The through holes are arranged on the surface according to the average distribution method, so that the position of the through holes is related to h. It also includes matching different sizes of hole diameters and arrangements according to different opening degrees to achieve different opening adjustment capabilities. The method of large holes plus small holes achieves pressure reduction and flow diversion under the premise of fluid regulation. The pressure impact is evenly distributed from the valve core sealing surface to each small hole through the small hole jet method to achieve pressure reduction and flow diversion. The through holes are set on the upper surface of the valve core using the same calculation method. The gradient direction of the through holes is opposite to that of the lower through holes of the valve core. As the stroke advances, the through holes become larger.

2. The four-stage cage-type regulating valve according to claim 1, characterized in that, A platform-shaped protrusion is formed at the transition point from the lower part to the upper part of the valve core, and the platform-shaped protrusion is stuck on the valve seat (2); There are 14 rows of through holes; of which: rows 1-5 have 30 through holes, rows 6-10 have 20 through holes, and rows 11-14 are drilled and adjusted according to on-site testing; different opening sizes and arrangements are matched with different orifice diameters under different opening degrees to achieve different opening adjustment capabilities. Large holes plus small holes achieve pressure reduction and flow diversion while ensuring fluid regulation. Pressure impact is evenly distributed from the valve core sealing surface to each small hole through the small hole jet method.

3. The four-stage cage-type regulating valve according to claim 2, characterized in that, Various sealing gaskets (14) are provided at the connection between the valve body (1), the pressure reducing sleeve, and the valve seat (2).

4. The four-stage cage-type regulating valve according to claim 2, characterized in that, The upper valve cover (9) and the valve body (1) are connected by bolt fasteners (10).

5. The four-stage cage-type regulating valve according to claim 1, characterized in that, The top of the upper valve cover (9) is provided with a groove, and the groove is filled with packing (11).

6. The four-stage cage-type regulating valve according to claim 5, characterized in that, A packing fixing assembly (12) is provided in the groove, and the valve stem (13) passes through the groove and the packing fixing assembly (12).

7. The four-stage cage-type regulating valve according to claim 5, characterized in that, The valve stem (13) is located at the center of the regulating valve and runs through the entire valve body.

8. The four-stage cage-type regulating valve according to claim 1, characterized in that, A guide sleeve (7) is provided between the bottom end of the upper valve cover (9) and the valve stem (13).

9. The four-stage cage-type regulating valve according to claim 8, characterized in that, The upper space of the valve core (5) and the pressure reducing sleeve (6) forms a balance space (804); the pressure reducing inner cylinder (61), valve core (5), upper valve cover (9), balance piston ring (8), valve stem (13) and balance space (804) constitute a balance structure; the fluid in the fluid passage achieves fluid pressure balance between the upper part of the valve core (5) and the lower part of the valve core (5) in the balance space (804), thus realizing the function of the balance structure.

10. The four-stage cage-type regulating valve according to claim 1, characterized in that, The bolt fasteners (10) are double-ended bolts and nuts.

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