A high-adjustment-ratio ultrahigh-pressure control valve

Abstract

This invention relates to the field of control valve technology, specifically a high-adjustability ultra-high pressure control valve. The invention includes a valve body and a valve cover. The valve body has a valve outlet, and the valve cover has a valve inlet. Within the cavity formed by the valve body and valve cover, an integral valve stem, valve seat, and valve cage are arranged coaxially. The valve seat is tightly abutted against and sealed to the valve body and valve cover by fasteners, and the valve cage is fixed within the valve body. The lower part of the integral valve stem is located within the valve cage, and the two can slide axially relative to each other. The upper end of the integral valve stem passes through the inner cavity of the valve body and is sealed by an ultra-high pressure packing assembly. The integral valve stem is provided with a throttling guide post, a throttling groove, a throttling cone surface, and a conical sealing surface. The valve seat is provided with a throttling guide hole, a throttling cone surface, and a conical sealing surface. The axial relative movement of the integral valve stem and valve seat achieves flow or pressure regulation. At a small opening, the invention achieves primary throttling between the throttling groove on the integral valve stem and the throttling guide hole on the valve seat, and secondary throttling between the throttling cone surface on the integral valve stem and the throttling cone surface on the valve seat. At large opening, throttling is achieved between the throttling guide column on the integral valve stem core and the throttling cone surface on the valve seat. At small opening, two-stage pressure reduction is connected in series, suitable for high pressure drop and low flow conditions; at large opening, single-stage pressure reduction is suitable for low pressure drop and high flow conditions. The valve adjusts smoothly, has a wide adjustment range, and a high adjustability ratio.

Description

A high-adjustable-ratio ultra-high pressure control valve Technical Field

[0001] This invention relates to the field of control valve technology, specifically to a high-adjustability ultra-high pressure control valve. Background Technology

[0002] Control valves with an operating pressure of not less than 100 MPa are generally referred to as ultra-high pressure control valves. In recent years, with the development of ultra-high pressure technology, ultra-high pressure control valves have been increasingly widely used in fields such as isostatic pressing in polyethylene production, artificial crystal, powder metallurgy, food pressure processing, waterjet cutting, and testing equipment. During operation, the ultra-high pressure medium inside an ultra-high pressure control valve stores enormous energy; an accident would be catastrophic. Control accuracy, sealing performance, and structural reliability all determine the safety and quality of ultra-high pressure operation. In the process equipment of the aforementioned ultra-high pressure applications, there are often operating conditions on the same pipeline requiring control of flow from low flow rate and high pressure drop to high flow rate and low pressure drop. This places demands on the selection of ultra-high pressure control valves to meet both stable flow or pressure control under low flow rate and high pressure drop conditions and smooth flow or pressure regulation under high flow rate and low pressure drop conditions. Existing ultra-high pressure control valves typically use a needle valve core structure to regulate the flow or pressure of ultra-high pressure media, with an inherent adjustable ratio generally between 30 and 50, resulting in a small flow or pressure regulation range that is difficult to meet the aforementioned special operating conditions. While using two ultra-high pressure control valves, one large and one small, in parallel for split-range control can meet the requirements of the aforementioned special operating conditions, it inevitably requires modifications to the ultra-high pressure pipeline to add loops and to add control points to the DCS, resulting in high costs and large investments. Therefore, this issue urgently needs to be addressed. Summary of the Invention

[0003] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a high adjustable ratio ultra-high pressure control valve with reasonable structure and practicality, which can adapt to the conveying control conditions from small flow and high pressure drop to large flow and low pressure drop.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A high-adjustable-ratio ultra-high-pressure control valve comprises an integral valve stem core, a valve seat, and a valve cage, all coaxially arranged within an inner cavity formed by a valve body and a valve cover. The valve seat is tightly abutted against and sealed to the valve body and the valve cover by fasteners. The valve cage is installed within the valve body, with no relative movement between the two. One side of the integral valve stem core is installed within the valve cage, allowing axial relative sliding between the two. One side of the integral valve stem core passes through the inner cavity of the valve body and is sealed by an ultra-high-pressure packing assembly. An actuator provides driving force to achieve axial relative movement between the integral valve stem core and the valve seat.

[0006] Preferably, the lower part of the integral valve stem core is provided with a guide cylinder, and the guide cylinder is uniformly provided with a plurality of throttling grooves along the circumference. The cross-section of the throttling grooves can be set to V-shape, U-shape, semi-circle or other irregular shape according to the process flow characteristics requirements, and the cross-sectional area gradually decreases along the axial direction. The upper part of the guide cylinder is provided with a throttling cone surface, the upper part of the throttling cone surface is provided with a conical sealing surface, and the upper part of the conical sealing surface is provided with a heavy-duty guide cylinder. The sealing surface and the heavy-duty guide cylinder are transitioned through the cone surface. The cone half angle of the throttling cone surface, the sealing surface and the transition cone surface increases sequentially. The heavy-duty guide cylinder is uniformly provided with a plurality of flow guiding and pressure equalizing grooves along the circumference. The cross-section of the flow guiding and pressure equalizing grooves can be set to semi-circle, V-shape, U-shape or other irregular shape, and the cross-sectional area remains unchanged along the axial direction.

[0007] Preferably, the valve seat adopts a conical pad, lens pad or other structural form, and is provided with a through hole in the axial direction. The through hole is provided with a cylindrical throttling guide hole, a truncated conical throttling cone surface and a truncated conical sealing surface in sequence from bottom to top. The cone half angle of the throttling cone surface is smaller than the cone half angle of the sealing surface.

[0008] Preferably, at a small opening, the cylindrical throttling guide hole on the valve seat is precisely fitted with the guide cylinder on the integral valve stem and valve core, and the two are axially slidably guided; at any opening, the heavy-duty guide cylinder on the integral valve stem and valve core is precisely fitted with the cylindrical surface of the inner cavity of the valve cage, and the two are axially slidably guided.

[0009] Preferably, at a small opening, the lower throttling groove of the integral valve stem core moves axially relative to the lower throttling guide hole of the valve seat, precisely controlling the change in the first-stage throttling area; simultaneously, the middle throttling cone surface of the integral valve stem core moves axially relative to the middle throttling cone surface of the valve seat, precisely controlling the change in the second-stage throttling area; the two throttling units are connected in series. At a large opening, the lower throttling guide column of the integral valve stem core moves axially relative to the middle throttling cone surface of the valve seat, precisely controlling the change in the throttling area; during the transition between small and large openings, the throttling area does not change abruptly.

[0010] Preferably, the valve body has a square shape and is made of high-strength steel integral forging. The valve body is provided with a transverse hole for forming a fluid outlet. The outlet end face of the valve body is provided with a threaded bolt hole and is connected to the ultra-high pressure pipeline through a threaded flange. It can be sealed with a lens gasket or a conical gasket.

[0011] Preferably, the valve cover is provided with an axial through hole for forming a fluid inlet, the valve cover is made of high-strength steel integral forging, the valve cover inlet is connected to the ultra-high pressure pipeline through a threaded flange, and can be sealed with a lens gasket or a conical gasket.

[0012] Preferably, the integral valve stem core is manufactured from an integral forging of mold steel that balances strength and toughness, and its surface can be subjected to surface hardening treatments such as WC diffusion, nitriding, STL hard alloy overlay, WC overlay, chrome plating, and QPQ.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. This invention, at a small valve opening, precisely controls the change in the first-stage throttling area through the relative axial movement between the throttling groove at the lower part of the integral valve stem core and the throttling guide hole at the lower part of the valve seat. Simultaneously, it precisely controls the change in the second-stage throttling area through the relative axial movement between the throttling cone surface at the middle of the integral valve stem core and the throttling cone surface at the middle of the valve seat, forming a two-stage pressure reduction system suitable for high pressure drop and low flow conditions. At a large valve opening, the throttling area is precisely controlled through the relative axial movement between the throttling guide column at the lower part of the integral valve stem core and the throttling cone surface at the middle of the valve seat, forming a single-stage pressure reduction system suitable for low pressure drop and high flow conditions. During the transition between small and large openings, the throttling area does not change abruptly, resulting in smooth adjustment and a wide valve adjustment range, with an adjustable ratio of 250~300.

[0015] 2. This invention effectively suppresses vibration and noise by setting a heavy-duty guide structure. At a small opening, on one hand, the throttling guide post at the lower part of the integral valve stem core precisely matches and slides axially relative to the throttling guide hole at the lower part of the valve seat; on the other hand, the heavy-duty guide post in the middle of the integral valve stem core precisely matches and slides axially relative to the inner surface of the valve cage, adapting to high pressure drop and low flow conditions. At a large opening, the heavy-duty guide post in the middle of the integral valve stem core slides axially with the inner surface of the valve cage, adapting to low pressure drop and high flow conditions.

[0016] 3. When the valve is open at a small degree, the present invention mainly throttles the flow through the throttling groove at the bottom of the integral valve stem core and the throttling guide hole at the bottom of the valve seat. The throttling surface is far away from the sealing surface of the integral valve stem core and the sealing surface of the valve seat, realizing the separation design of the sealing surface and the throttling surface. This effectively protects the sealing surface from being eroded and damaged by the high-speed medium flow when the valve is open at a small degree, thereby improving the sealing life.

[0017] 4. This invention features a simple structure, high reliability, and high cost-effectiveness. The valve seat, valve body, and valve cover employ a lens gasket or conical gasket metal hard seal, ensuring high sealing reliability. The integrated design of the valve stem core provides excellent strength and rigidity. The bottom-in, side-out medium flow direction ensures the valve stem is only subjected to compressive stress, preventing fatigue fracture caused by alternating tensile and compressive stresses. Its high adjustability allows it to replace two separate ultra-high pressure control valves (one large and one small) used for segmented control, effectively reducing costs. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the overall structure of Embodiment 1 of the present invention.

[0019] Figure 2 is a partial schematic diagram of the integral valve stem core when it is fully closed in the structure of Embodiment 1 of the present invention.

[0020] Figure 3 is a partial schematic diagram of the integral valve stem core portion when it is open in the structure of Embodiment 1 of the present invention.

[0021] Figure 4 is a partial schematic diagram of the overall valve stem core when it is fully open in the structure of Embodiment 1 of the present invention.

[0022] Figure 5 is a partial isometric view of the integral valve stem core in Embodiment 1 of the present invention.

[0023] Figure 6 is a schematic diagram of the overall structure of Embodiment 2 of the present invention.

[0024] In the diagram: 10, threaded flange; 20, valve cover; 20a, valve inlet; 30, valve seat; 30a, throttling guide hole; 30b, first throttling cone surface; 30c, first conical sealing surface; 40, integral valve stem core; 40a, throttling guide column; 40b, throttling groove; 40c, second throttling cone surface; 40d, second conical sealing surface; 40e, flow guiding and pressure equalizing groove; 40f, heavy-duty guide column; 40g, valve stem; 50, valve body; 50a, valve outlet; 60, valve cage; 60a, upper cavity of valve cage; 70, ultra-high pressure packing assembly; 80, packing pressure ring; 90, packing clamping nut; 100, bracket; 110, actuator. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1:

[0027] As shown in Figures 1-5, a high-adjustability ultra-high pressure control valve mainly includes, from top to bottom, an actuator 110, a bracket 100, a packing clamping nut 90, a packing ring 80, an ultra-high pressure packing assembly 70, a valve cage 60, a valve body 50, an integral valve stem core 40, a valve seat 30, a valve cover 20, and a threaded flange 10. The valve cage 40 is coaxially interference-fitted with the inner cavity of the valve body 50. The upper end face of the valve cage 60 abuts against the end face of the inner cavity of the valve body 50. The valve seat 30 adopts a lens gasket sealing structure with the valve body 50 and the valve cover 20. Sufficient preload is provided by bolt connection. The upper and lower spherical sealing surfaces of the valve seat 30 abut tightly against the conical sealing surfaces of the valve body 50 and the valve cover 20, respectively, to achieve reliable ultra-high pressure static sealing and prevent leakage of ultra-high pressure medium. The valve body is approximately hexahedral in shape. The valve body and valve cover are made of Cr-Ni-Mo-V high-strength low-alloy steel integral forgings. It is connected to the ultra-high pressure pipeline through threaded flange 10 and sealed by lens gasket.

[0028] The valve seat 30, integral valve stem core 40, valve cage 60, and ultra-high pressure packing assembly 70 are coaxial with each other. The valve stem 40g and the packing gland of the valve body 50 achieve ultra-high pressure dynamic and static sealing through the ultra-high pressure packing assembly 70 to prevent leakage of ultra-high pressure medium. The packing compression nut 90 is threaded to the valve body 50 and transmits axial force through the packing pressure ring 80 to provide the initial preload required for sealing of the ultra-high pressure packing assembly 70. The ultra-high pressure packing assembly 70 adopts an alternating arrangement of polymer V-shaped packing and copper alloy spacer rings to achieve self-tightening sealing through ultra-high pressure medium.

[0029] The actuator 110 drives the integral valve stem core 40 to move axially relative to the valve seat 30, precisely controlling the continuous change of the throttling area to achieve precise regulation of flow or pressure. When the second conical sealing surface 40d is in complete contact with the first conical sealing surface 30c, the actuator 110 provides sufficient driving force to overcome the unbalanced force of the medium and the friction of the packing, achieving a tight shut-off function and preventing internal leakage of ultra-high pressure medium.

[0030] The integral valve stem core 40 is equipped with a heavy-duty guide post 40f, which precisely fits with the cylindrical surface of the inner cavity of the valve cage 60 and provides axial relative sliding guidance. The integral valve stem core 40 is also equipped with a throttling guide post 40a, which precisely fits with the throttling guide hole 30a on the valve seat 30 and provides axial relative sliding guidance at small openings. A semi-circular pressure equalization groove 40e on the integral valve stem core 40 ensures pressure equalization between the upper cavity 60a of the valve cage and the inner cavity of the valve body 50, preventing the formation of local dead spaces. The integral valve stem core 40 is manufactured as a single forging from hot-work die steel. The valve stem 40g surface is chrome-plated, and the remaining surfaces are PTA plasma-welded with STL1 hard alloy to ensure long-term reliable use.

[0031] At a small opening, the change in the first-stage throttling area is precisely controlled by the relative axial movement between the V-shaped throttling groove 40b at the lower part of the integral valve stem core 40 and the throttling guide hole 30a at the lower part of the valve seat 30. Similarly, the change in the second-stage throttling area is precisely controlled by the relative axial movement between the second throttling cone surface 40c at the middle of the integral valve stem core 40 and the first throttling cone surface 30b at the middle of the valve seat. At a large opening, the change in the throttling area is precisely controlled by the relative axial movement between the throttling guide column 40a at the lower part of the integral valve stem core 40 and the first throttling cone surface 30b at the middle of the valve seat 30. During the transition between small and large openings, the throttling area does not change abruptly, resulting in smooth adjustment. At a small opening, a two-stage pressure reduction is formed in series, suitable for high pressure drop and low flow conditions; at a large opening, a single-stage pressure reduction is achieved, suitable for low pressure drop and high flow conditions.

[0032] Example 2:

[0033] As shown in Figure 6, the difference between this embodiment and embodiment 1 is that the valve seat 30 adopts a conical gasket sealing structure with the valve body 50 and valve cover 20. Sufficient preload is provided by bolt connection. The upper and lower conical sealing surfaces of the valve seat 30 are tightly abutted against the sealing edges of the valve body 50 and valve cover 20, respectively, to achieve reliable ultra-high pressure static sealing and prevent leakage of ultra-high pressure medium.

[0034] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-adjustable-ratio ultra-high pressure control valve, comprising a valve body (50) and a valve cover (20), wherein the valve body (50) is provided with a valve outlet (50a) and the valve cover (20) is provided with a valve inlet (20a), characterized in that: The inner cavity formed by the valve body (50) and the valve cover (20) is provided with an integral valve stem core (40), a valve seat (30), and a valve cage (60) arranged coaxially with each other; the valve seat (30) is tightly abutted against the valve body (50) and the valve cover (20) by fasteners and is sealed; the valve cage (60) is installed in the valve body (50) and there is no relative movement between the two; the lower part of the integral valve stem core (40) is located in the valve cage (60) and the two can slide axially relative to each other; the upper end of the integral valve stem core (40) passes through The valve body (50) is sealed through the inner cavity and the ultra-high pressure packing assembly (70); the integral valve stem core (40) is provided with a throttling guide post (40a), a throttling groove (40b), a second throttling cone surface (40c), and a second conical sealing surface (40d); the valve seat (30) is axially penetrated and is provided with a throttling guide hole (30a), a first throttling cone surface (30b), and a first conical sealing surface (30c) in sequence and coaxially; the integral valve stem core (40) and the valve seat (30) move axially relative to each other to achieve flow or pressure. Adjustment; when fully closed, the second conical sealing surface (40d) and the first conical sealing surface (30c) are tightly fitted and sealed; when the opening is small, a first-stage throttling is formed between the throttling groove (40b) and the throttling guide hole (30a), and a second-stage throttling is formed between the second throttling conical surface (40c) and the first throttling conical surface (30b); when the opening is large, throttling is formed between the throttling guide post (40a) and the first throttling conical surface (30b); the throttling guide post (40a) is disposed in the integral valve At the lower part of the rod core (40), the throttling groove (40b) is uniformly arranged circumferentially on the throttling guide post (40a); at the upper part of the throttling guide post (40a), the second throttling cone surface (40c), the second cone sealing surface (40d) and the heavy-duty guide post (40f) are arranged coaxially in sequence, and the second cone sealing surface (40d) and the heavy-duty guide post (40f) are transitioned by a truncated cone surface; the cone half angle of the second throttling cone surface (40c), the second cone sealing surface (40d) and the truncated cone surface increases sequentially.

2. The high-adjustable ratio ultra-high pressure control valve according to claim 1, characterized in that: The valve seat (30) is made of a conical pad or a lens pad; the throttling guide hole (30a) is located at the lower part of the through hole of the valve seat (30), and the cone half angle of the first throttling cone surface (30b) is smaller than the cone half angle of the first conical sealing surface (30c).

3. The high-adjustable ratio ultra-high pressure control valve according to claim 1, characterized in that: The cross-section of the throttling groove (40b) can be set to V-shape, U-shape or semi-circle according to the process flow characteristics requirements, and the cross-sectional area gradually decreases along the axial direction.

4. The high-adjustable ratio ultra-high pressure control valve according to claim 1, characterized in that: The heavy-duty guide column (40f) has several flow-guiding and pressure-equalizing grooves (40e) evenly arranged circumferentially on its cylindrical surface.

5. The high-adjustable-ratio ultra-high pressure control valve according to claim 4, characterized in that: The cross-section of the flow guiding and equalizing groove (40e) can be set to V-shape, U-shape or semi-circle, and the cross-sectional area remains unchanged along the axial direction.

6. The high-adjustable-ratio ultra-high pressure control valve according to claim 1, characterized in that: The valve body (50) is a square shape and is made of high-strength steel integral forging; a valve outlet (50a) is provided on one side of the transverse hole, and a wire bolt hole is provided on the same side, which is bolted to the ultra-high pressure pipeline threaded flange (10) and sealed with a lens gasket or a conical gasket.

7. The high-adjustable ratio ultra-high pressure control valve according to claim 1, characterized in that: The valve cover (20) is made of high-strength steel integral forging, axially penetrating, with a valve inlet (20a) at one end, which is bolted to the ultra-high pressure pipeline threaded flange (10) and sealed with a lens gasket or a conical gasket.

8. The high-adjustable ratio ultra-high pressure control valve according to claim 1, characterized in that: The integral valve stem core (40) is made of mold steel integral forging and the surface can be hardened.

9. A high-adjustable ratio ultra-high pressure control valve according to claim 8, characterized in that: Hardening treatments include WC diffusion, nitriding, STL hard alloy overlay, WC overlay, chrome plating, or QPQ plating.

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