Ultrahigh pressure control valve with high adjustable ratio

Abstract

The invention relates to the technical field of control valves, in particular to a high-adjustable-ratio ultrahigh pressure control valve. The valve comprises a valve body and a valve cover, the valve body is provided with a valve outlet, the valve cover is provided with a valve inlet, and an integral valve rod core, a valve seat and a valve cage which are coaxially arranged are arranged in an inner cavity defined by the valve body and the valve cover; the valve seat tightly abuts against the valve body and the valve deck through a fastener and is sealed, and the valve cage is fixed in the valve body. The lower portion of the integral valve rod core is located in the valve cage, the integral valve rod core and the valve cage can axially slide relatively, and the upper end of the integral valve rod core penetrates through an inner cavity of the valve body and is sealed through an ultrahigh-pressure packing assembly. The integral valve rod core is provided with a throttling guide column, a throttling groove, a throttling conical surface and a conical sealing surface; the valve seat is provided with a throttling guide hole, a throttling conical surface and a conical sealing surface; the integral valve rod core and the valve seat move relatively in the axial direction to achieve flow or pressure adjustment. When the opening degree is small, first-stage throttling is achieved between the throttling groove in the integral valve rod core and the throttling guide hole in the valve seat, and second-stage throttling is formed between the throttling conical surface on the integral valve rod core and the throttling conical surface on the valve seat. And when the opening degree is large, throttling is realized between the throttling guide column on the integral valve rod core and the throttling conical surface on the valve seat. When the opening degree is small, two-stage pressure reduction is connected in series and suitable for high-pressure-drop and small-flow working conditions; and single-stage pressure reduction is achieved during large opening, and the device is suitable for low-pressure-drop and large-flow working conditions. The valve is adjusted smoothly, the adjusting range is wide, and the adjustable ratio is high.

Description

Technical Field

[0001] The present invention relates to the technical field of control valves, and particularly to a high adjustable ratio ultra-high pressure control valve. Background Art

[0002] Control valves with an operating pressure not lower than 100 MPa are usually called ultra-high pressure control valves. In recent years, with the development of ultra-high pressure technology, ultra-high pressure control valves have been gradually widely used in fields such as isostatic pressing in polyethylene production, artificial crystal, powder metallurgy, food pressure processing, water jet cutting, and test devices. When an ultra-high pressure control valve operates, the ultra-high pressure medium inside stores huge energy. Once an accident occurs, it will be catastrophic. Control accuracy, sealing performance, structural reliability, etc. all determine the safety and quality of ultra-high pressure operation. In the process devices in the above ultra-high pressure application fields, there are often working conditions on the same pipeline that require the realization of conveying control from a small flow rate and high pressure drop to a large flow rate and low pressure drop. The requirements for the selection of ultra-high pressure control valves are to not only meet the stable control of the flow rate or pressure under the conditions of small flow rate and high pressure drop, but also be suitable for the smooth adjustment of the flow rate or pressure under the conditions of large flow rate and low pressure drop. Existing ultra-high pressure control valves usually adopt a needle-type valve core structure to adjust the flow rate or pressure of ultra-high pressure media, and the inherent adjustable ratio is generally 30 - 50, with a small flow rate or pressure adjustment range, making it difficult to meet the above special working conditions. Using the method of parallel connection of one large and one small ultra-high pressure control valves for split range control can meet the requirements of the above special working conditions, but inevitably, it is also necessary to transform the ultra-high pressure pipeline to add a circuit and add control points on the DCS, with high costs and large investments, so it needs to be solved urgently. 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 a reasonable structure and practicality, which can adapt to the conveying control working conditions from a small flow rate and high pressure drop to a large flow rate and low pressure drop.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A high adjustable ratio ultra-high pressure control valve, in the inner cavity surrounded by the valve body and the valve cover, there are arranged a whole valve stem core, a valve seat and a valve cage that are coaxial with each other; the valve seat is tightly abutted against the valve body and the valve cover through fasteners and sealed; the valve cage is installed in the valve body, and there is no relative movement between the two; the valve core side of the whole valve stem core is installed in the valve cage, and the two can axially slide relative to each other; the valve stem side of the whole valve stem core passes through the inner cavity of the valve body and is sealed through an ultra-high pressure packing assembly; the actuator provides driving force to realize the axial relative movement between the whole valve stem core and the valve seat.

[0006] Preferably, a guiding cylinder is provided at the lower part of the integral valve stem core. A plurality of throttling grooves are evenly arranged along the circumferential direction of the guiding cylinder. The cross-section of the throttling groove can be set as V-shaped, U-shaped, semi-circular or other special-shaped according to the process flow characteristics requirements, and the cross-sectional area gradually decreases along the axial direction; a throttling conical surface is provided at the upper part of the guiding cylinder, a conical sealing surface is provided at the upper part of the throttling conical surface, a heavy-duty guiding cylinder is provided at the upper part of the conical sealing surface, and the sealing surface and the heavy-duty guiding cylinder are in transition through a conical surface. The cone half-angles of the throttling conical surface, the sealing surface and the transition conical surface increase in sequence; a plurality of diversion and pressure equalizing grooves are evenly arranged along the circumferential direction of the heavy-duty guiding cylinder. The cross-section of the diversion and pressure equalizing groove can be set as semi-circular, V-shaped, U-shaped or other special-shaped, and the cross-sectional area remains unchanged along the axial direction.

[0007] Preferably, the valve seat adopts a conical gasket, a lens gasket or other structural forms, and a through hole is axially arranged. The through hole is sequentially provided with a cylindrical throttling guiding hole, a truncated conical throttling conical surface and a truncated conical sealing surface from bottom to top. The cone half-angle of the throttling conical surface is smaller than the cone half-angle of the sealing surface.

[0008] Preferably, at a small opening degree, the cylindrical throttling guiding hole on the valve seat is in precise fit with the guiding cylinder on the integral valve stem valve core and axially relatively slides for guiding; at any opening degree, the heavy-duty guiding cylinder on the integral valve stem core is in precise fit with the inner cylindrical surface of the valve cage and axially relatively slides for guiding.

[0009] Preferably, at a small opening degree, the throttling grooves at the lower part of the integral valve stem core and the throttling guiding holes at the lower part of the valve seat move axially relative to each other to precisely control the change of the primary throttling area; at the same time, the throttling conical surfaces in the middle of the integral valve stem core and the throttling conical surfaces in the middle of the valve seat move axially relative to each other to precisely control the change of the secondary throttling area; the two-stage throttling units are connected in series. At a large opening degree, the throttling guiding column at the lower part of the integral valve stem core and the throttling conical surface in the middle of the valve seat move axially relative to each other to precisely control the change of the throttling area; when adjusting the transition between a small opening degree and a large opening degree, the throttling area does not generate a sudden change.

[0010] Preferably, the valve body has a square shape and is made of a high-strength steel integral forging. The valve body is provided with a transverse hole for forming a fluid outlet. A tapping bolt hole is provided on the outlet end face of the valve body, and it is connected to the ultra-high pressure pipeline through a threaded flange and 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 a high-strength steel integral forging. The inlet of the valve cover 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 made of an integral forging of die steel that takes into account both strength and toughness, and the surface can be subjected to surface hardening treatments such as WC infiltration, nitriding, surfacing of STL hard alloy, surfacing of WC, chromium plating, QPQ, etc.

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

[0014] 1. In the case of a small opening degree, on the one hand, through the relative axial movement between the lower throttle groove of the integral valve stem core and the lower throttle guiding hole of the valve seat, the change of the primary throttle area is precisely controlled. On the other hand, through the relative axial movement between the middle throttle cone surface of the integral valve stem core and the middle throttle cone surface of the valve seat, the change of the secondary throttle area is precisely controlled, forming a series of two-stage pressure reduction, which is suitable for working conditions with high pressure drop and small flow rate. When the opening degree is large, through the relative axial movement between the lower throttle guiding column of the integral valve stem core and the middle throttle cone surface of the valve seat, the change of the throttle area is precisely controlled, forming a single-stage pressure reduction, which is suitable for working conditions with low pressure drop and large flow rate. When adjusting the transition between small and large opening degrees, the throttle area does not produce sudden changes, the adjustment is smooth, the valve has a wide adjustment range, and the adjustable ratio reaches 250 - 300.

[0015] 2. The present invention can effectively suppress vibration and noise by setting a heavy-duty guiding structure. When the opening degree is small, on the one hand, through the precise fit and axial relative sliding guiding between the lower throttle guiding column provided at the lower part of the integral valve stem core and the lower throttle guiding hole provided at the lower part of the valve seat, and on the other hand, through the precise fit and axial relative sliding guiding between the heavy-duty guiding column provided in the middle of the integral valve stem core and the inner surface of the valve cage, it adapts to the working conditions of high pressure drop and small flow rate. When the opening degree is large, through the axial sliding guiding between the heavy-duty guiding column provided in the middle of the integral valve stem core and the inner surface of the valve cage, it adapts to the working conditions of low pressure drop and large flow rate.

[0016] 3. When the opening degree is small, the present invention mainly throttles through the lower throttle groove of the integral valve stem core and the lower throttle guiding hole of the valve seat. The throttle surface is far from the sealing surfaces of the integral valve stem core and the valve seat, realizing the separation design of the sealing surface and the throttle surface, effectively protecting the sealing surface from being scoured and damaged by the high-speed medium flow at small opening degrees, and improving the sealing life.

[0017] 4. The structure of the present invention is simple, has good reliability and high cost performance. The lens gasket or conical gasket metal hard seal form is adopted between the valve seat and the valve body and the valve cover, and the sealing reliability is good; the integral valve stem core is integrally designed, and the strength and stiffness are good; the medium flow direction from the bottom to the side makes the valve stem only under compressive stress, preventing the fatigue fracture failure of the valve stem caused by the alternating action of tensile stress and compressive stress; the adjustable ratio with high adjustment characteristics can replace two ultra-high pressure control valves of different sizes used for split range adjustment, effectively reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0019] Figure 2 This is a partial schematic view of the overall valve stem core in the fully closed state in the structure of Embodiment 1 of the present invention.

[0020] Figure 3 This is a partial schematic view of the overall valve stem core in the partially opened state in the structure of Embodiment 1 of the present invention.

[0021] Figure 4 This is a partial schematic view of the overall valve stem core in the fully opened state in the structure of Embodiment 1 of the present invention.

[0022] Figure 5 This is a partial axonometric view of the overall valve stem core in the structure of Embodiment 1 of the present invention.

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

[0024] In the figure: 10, threaded flange; 20, valve cover; 20a, valve inlet; 30, valve seat; 30a, throttling guide hole; 30b, throttling conical surface; 30c, sealing surface; 40, overall valve stem core; 40a, throttling guide post; 40b, throttling groove; 40c, throttling conical surface; 40d, sealing surface; 40e, flow guiding and pressure equalizing groove; 40f, heavy-duty guide post; 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 gland; 90, packing compression nut; 100, bracket; 110, actuator. Detailed implementation manners

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] Embodiment 1:

[0027] As Figures 1 to 5As shown in the figure, a high adjustable ratio ultra-high pressure control valve mainly includes an actuator 110, a bracket 100, a packing compression nut 90, a packing gland 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, a threaded flange 10, etc., which are arranged in sequence from top to bottom. The valve cage 40 is in interference fit with the inner cavity of the valve body 50 coaxially. The upper end face of the valve cage 60 abuts against the inner cavity end face of the valve body 50. A lens gasket sealing structure is adopted between the valve seat 30, the valve body 50 and the valve cover 20, and sufficient pre-tightening force is provided through bolt connection. The upper and lower spherical sealing surfaces of the valve seat 30 closely abut against the conical sealing surfaces of the valve body 50 and the valve cover 20 respectively to achieve reliable ultra-high pressure static seal and prevent ultra-high pressure medium from leaking out. The outer shape of the valve body is approximately a hexahedron. The valve body and the valve cover are made of integral forgings of Cr-Ni-Mo-V high-strength low-alloy steel, and are connected to the ultra-high pressure pipeline through the threaded flange 10 and sealed through a lens gasket.

[0028] The valve seat 30, the integral valve stem core 40, the valve cage 60, and the ultra-high pressure packing assembly 70 are coaxial with each other. The stuffing box of the valve stem 40g and the valve body 50 realizes ultra-high pressure dynamic and static seals through the ultra-high pressure packing assembly 70 to prevent ultra-high pressure medium from leaking out. The packing compression nut 90 is connected to the valve body 50 through threads, and the axial force is transmitted through the packing gland 80 to provide the initial pre-tightening force required for the seal of the ultra-high pressure packing assembly 70. The ultra-high pressure packing assembly 70 adopts a method of alternately arranging polymer V-shaped packings and copper alloy spacer rings, and realizes self-tightening seal 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 adjustment of flow or pressure; when the sealing surface 40d of the integral valve stem core is in full contact with the sealing surface 30c of the valve seat, sufficient driving force is provided through the actuator 110 to overcome the medium unbalance force and packing friction force to achieve a tight shut-off function and prevent ultra-high pressure medium from leaking in.

[0030] Heavy guide columns 40f are arranged on the integral valve stem core 40, which are in precise fit with the inner cylindrical surface of the valve cage 60 and slide axially relative to each other for guiding; Throttle guide columns 40a are arranged on the integral valve stem core 40, which are in precise fit with the throttle guide holes 30a arranged on the valve seat 30 and slide axially relative to each other for guiding at small openings. Through the semi-circular diversion and pressure equalizing grooves 40e arranged on the integral valve stem core 40, pressure equalization is achieved between the upper cavity 60a of the valve cage and the inner cavity of the valve body 50 to prevent the formation of local dead cavities. The integral valve stem core 40 is made of integral forgings of hot work die steel. The surface of the valve stem 40g is chrome-plated, and the rest of the surface is plasma surfacing welded with STL1 hard alloy by PTA to ensure long-term reliable use.

[0031] At small openings, through the relative axial movement between the V-shaped throttling groove 40b provided at the lower part of the integral valve stem core 40 and the throttling guide hole 30a provided at the lower part of the valve seat 30, the change of the primary throttling area is precisely controlled; through the relative axial movement between the throttling conical surface 40c provided in the middle of the integral valve stem core 40 and the throttling conical surface 30b provided in the middle of the valve seat, the change of the secondary throttling area is precisely controlled. At large openings, through the relative axial movement between the throttling guide post 40a provided at the lower part of the integral valve stem core 40 and the throttling conical surface 30b provided in the middle of the valve seat 30, the change of the throttling area is precisely controlled. During the transition between small and large opening adjustments, the throttling area does not undergo sudden changes, and the adjustment is smooth. A series of two-stage pressure reduction is formed at small openings, which is suitable for high pressure drop and small flow conditions; single-stage pressure reduction is achieved at large openings, which is suitable for low pressure drop and large flow conditions.

[0032] Embodiment 2:

[0033] As Figure 6 shown, the difference between this embodiment and Embodiment 1 is that a tapered gasket sealing structure is adopted between the valve seat 30, the valve body 50 and the valve cover 20. Sufficient pre-tightening force is provided through bolt connection. The upper and lower tapered sealing surfaces of the valve seat 30 are respectively tightly abutted against the sealing edges of the valve body 50 and the valve cover 20 to achieve reliable ultra-high pressure static sealing and prevent ultra-high pressure medium from leaking out.

[0034] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent replacements or changes should be covered within the protection scope 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: An integral valve stem core (40), a valve seat (30) and a valve cage (60) which are coaxially arranged with each other are provided in the inner cavity surrounded by the valve body (50) and the valve cover (20); the valve seat (30) is tightly pressed against the valve body (50) and the valve cover (20) by fasteners and sealed; the valve cage (60) is installed in the valve body (50), and the two do not move relative to each other; 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 upper part of the integral valve stem core (40) passes through the inner cavity of the valve body (50) and is sealed by the ultra-high pressure packing assembly (70); a throttling guide column (40a), a throttling groove (40b), a throttling cone surface (40c) and a throttling groove (40d) are provided on the integral valve stem core (40). 0c) and a conical sealing surface (40d), the valve seat (30) axially penetrates and coaxially arranges a throttling guide hole (30a), a throttling cone surface (30b) and a conical sealing surface (30c) in sequence; the integral valve stem core (40) and the valve seat (30) axially move relative to each other to achieve flow or pressure regulation; when fully closed, the conical sealing surface (40d) and the conical sealing surface (30c) are tightly fitted and sealed; when the opening is small, a first-level throttling is formed between the throttling groove (40b) and the throttling guide hole (30a), and a second-level throttling is formed between the throttling cone surface (40c) and the throttling cone surface (30b); when the opening is large, throttling is formed between the throttling guide column (40a) and the throttling cone surface (30b).

2. The high adjustable ratio ultra-high pressure control valve according to claim 1, characterized in that: The throttling guide column (40a) is arranged at the lower part of the integral valve stem core (40), and the throttling groove (40b) is evenly arranged on the throttling guide column (40a) in the circumferential direction; the throttling cone surface (40c), the conical sealing surface (40d) and the heavy-duty guide column (40f) are coaxially arranged in sequence on the upper part of the throttling guide column (40a), and the conical sealing surface (40d) and the heavy-duty guide column (40f) are transitioned through a truncated cone surface; the cone half angles of the throttling cone surface (40c), the conical sealing surface (40d) and the transition cone surface increase in sequence.

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

4. A high adjustable ratio ultra-high pressure control valve according to claim 1 or 2, characterized in that: The cross section of the throttling groove (40b) can be set to be V-shaped, U-shaped or semicircular according to the process flow characteristic requirements, and the cross-sectional area gradually decreases along the axial direction.

5. A high adjustable ratio ultra-high pressure control valve according to claim 1 or 2, characterized in that: A plurality of flow-guiding and pressure-equalizing grooves (40e) are evenly arranged along the circumferential direction on the cylindrical surface of the heavy-duty guide column (40f).

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

7. The high adjustable ratio ultra-high pressure control valve according to claim 1, characterized in that: The valve body (50) is in the shape of a square and is made of a high-strength steel integral forging. A valve outlet (50a) is arranged on one side of the transverse hole, and a threaded bolt hole is arranged 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.

8. The high adjustable ratio ultra-high pressure control valve according to claim 1, characterized in that: The valve cover (20) is made of a high-strength steel integral forging, is axially penetrated, and is provided 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.

9. A high adjustable ratio ultra-high pressure control valve according to claim 1 or 2, characterized in that: The integral valve stem core (40) is manufactured from an integral die steel forging, and the surface thereof may be hardened.

10. The high adjustable ratio ultra-high pressure control valve according to claim 9, characterized in that: Hardening treatments include WC, nitriding, STL carbide cladding, WC cladding, chrome plating or QPQ.

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