A kind of super high pressure sand control open stem flat valve driven by ball screw without tail rod

Abstract

A kind of super-high pressure sand control type open stem flat valve driven by ball screw, characterized in that: a handwheel rotating component is installed above the valve cover component and the valve stem part, a ball screw pair connected with the valve stem is installed in the handwheel rotating component, and a locking mechanism for allowing or prohibiting the rotation of the handwheel and the screw nut is added on one side of the handwheel rotating component; at the contact between the central hole of the valve cover component and the valve stem at the upper end of the valve body, a set of combined seals stacked by multiple non-rubber seals with different cross-sections is installed; in the cylindrical valve cavity of the valve body, below the valve seat, a pair of sand control plates filled with the valve cavities on both sides of the gate plate and with elastic rubber rings are symmetrically installed. The open stem flat valve without tail rod realizes new functions such as easy operation, reliable sealing, wear and corrosion resistance, sand control and blockage prevention while maintaining a small volume, switch display, low price and convenient maintenance, so that it is more suitable for use under harsh working conditions such as super-high pressure fracturing operations.

Description

Technical Field

[0001] The present invention relates to a "manual exposed stem flat valve" used in the oil machinery and other industries. Background Art

[0002] The tailless stem manual exposed stem flat valve is a large-diameter gate valve commonly used in high- and medium-pressure oil drilling and production equipment, which has the advantages of small product volume, light weight, low price, and directly showing the valve opening and closing conditions. However, with the continuous increase of the depth of oil and gas wells and the continuous improvement of the working pressure level, the existing sand-proof tailless stem manual exposed stem flat valve is difficult to meet the operation requirements of ultra-high pressure conditions. Its main problems are as follows: First, since the valve has no tail rod for pressure balance, the valve stem bears the medium pressure unidirectionally; in addition, the friction coefficient of the ball screw pair is small and there is no self-locking function; therefore, in ultra-high pressure conditions, if a trapezoidal thread pair with a self-locking function is still used to drive the valve, it is impossible for ordinary people to operate. Second, almost all the sand-proof plates installed on both sides of the gate are flat plates, with insufficient rigidity. In ultra-high pressure conditions, elastic or plastic deformation is likely to occur, so that some sand-containing media enter the valve cavity, causing sand plugging accidents; in addition, there is no active adhesion force between the sand-proof plate and the gate, and the fixed free gap formed by its precision machining increases with the increase of working time and part deformation, providing a gap for the sand-containing media to enter the valve cavity. Third, the rubber combined seal used at the valve cover and valve stem of the flat valve is difficult to meet the requirements of ultra-high pressure conditions and frequent operations; for a few valve stem combined seals using composite materials, due to fewer layers or poor matching, their sealing performance and service life are not ideal. Fourth, for the existing flat valves, when the valve is closed to the end, it is required that the operator rotate the handwheel about one circle according to the valve stem pitch and design allowance, so that the bottom surface of the gate is separated from the valve body and the lower end of the valve stem is separated from the gate, so that the gate and the valve seat are in a floating state, so that the valve seat seal ring with limited elasticity can produce the best sealing effect without external force coercion; however, due to various reasons, normal-performance flat valves often leak due to improper operation during closing. Summary of the Invention

[0003] The purpose of the present invention is to provide a tailless stem manual exposed stem flat valve driven by a ball screw pair, suitable for ultra-high pressure conditions, and having excellent sand-proof, sealing, and anti-leakage functions.

[0004] The present invention is composed of a handwheel rotating component, a valve cover component, a valve body, a valve stem, a gate plate, a valve seat, a sand prevention plate, a guide plate part, as well as supporting seals and connectors; its special features are as follows: A handwheel rotating component is installed above the valve cover component and the valve stem part. A ball screw pair connected to the valve stem is installed inside the handwheel rotating component. On one side of the handwheel rotating component, a locking mechanism is added to allow or prohibit the rotation of the handwheel and the screw nut. At the upper end of the valve body, at the contact between the central hole of the valve cover component and the valve stem, a combined seal composed of multiple non-rubber seals with different cross-sections stacked together is installed. In the cylindrical valve cavity of the valve body, symmetrically below the valve seat, a pair of sand prevention plates filled with the valve cavities on both sides of the gate plate and with elastic rubber rings are installed.

[0005] Since the present invention takes the lead in adopting a ball screw pair drive, the opening and closing resistance of the valve can be greatly reduced; the handwheel is located in the middle of the handwheel rotating component, which can reduce the height of the valve and shrink the product volume; above the handwheel, a transparent protective cover is used to cooperate with the screw in the ball screw pair, which can visually display the opening and closing conditions of the valve; on one side of the handwheel rotating component, a locking mechanism is added to allow or prohibit the rotation of the handwheel and the screw nut, which can not only avoid the abnormal situation that when the valve is closed, the gate plate and the valve stem push the ball screw pair without self-locking ability to rotate under the pressure in the valve cavity and then automatically open the valve, but also leave a floating gap for the gate plate after the valve is closed to improve the sealing effect of the valve. At the upper end of the valve body, at the contact between the central hole of the valve cover component and the valve stem, a combined seal composed of multiple non-rubber seals with different cross-sections stacked together is installed, which organically combines the sealing functions of multiple composite material seals to achieve multiple seals and super compressive resistance, wear resistance and corrosion resistance effects. In the valve cavity, symmetrically below the valve seat, a pair of sand prevention plates filled with the valve cavities on both sides of the gate plate and with elastic rubber rings are installed, which can not only improve the strength of the sand prevention plate and eliminate the space for its deformation, but also utilize the elasticity generated by the rectangular seal in the sand prevention plate component to always actively fit tightly with the gate plate, without leaving any gap for the sand-containing medium to enter the valve cavity. Brief Description of the Drawings

[0006] Figure 1 It is a full-sectional view schematic diagram of the fully open state of the valve of the overall structure of the present invention;

[0007] Figure 2 It is Figure 1 In it, it is an enlarged schematic diagram of the A-A cross-section at the joint of the valve body, the gate plate and the sand prevention plate;

[0008] Figure 3 It is a partial enlarged schematic diagram of the combined seal at the contact between the valve cover and the valve stem in the present invention;

[0009] Figure 4 It is a three-dimensional enlarged schematic diagram of the sand prevention plate part in the present invention;

[0010] Figure 5 In the present invention, it is a schematic enlarged view of the cross-section of the elastic rubber ring that is matched with the sand control plate;

[0011] Figure 6 In the handwheel rotating component of the present invention, it is a schematic enlarged view when the small component of the locking mechanism is locked.

[0012] The names of the components indicated by the reference numerals in the figure are as follows:

[0013] 1. Valve body, 2. Sealing gasket ring, 3. Valve cover, 4. Stud nut, 5. Bearing housing, 6. Locking mechanism, 601. Elastic bolt, 602. Fixed sleeve, 603. Compression spring, 604. Slotted nut, 605. Pull ring, 606. Set screw, 7. Rotating shaft sleeve, 8. Handwheel, 9. Transparent protective cover, 10. Oil cup, 11. Ball screw pair, 12. Hexagon socket head screw, 13. Screw washer, 14. O-ring, 15. Thrust bearing, 16. Cylindrical pin, 17. Combined seal, 18. Set screw, 19. Valve stem, 20. Grease injection valve, 21. Gate plate, 22. Valve seat, 23. Inner seal ring, 24. Outer seal ring, 25. Sand control plate, 26. Elastic rubber ring, 27. Guide plate. Detailed implementation manners

[0014] The following further describes the detailed implementation manners of the present invention with reference to the accompanying drawings:

[0015] Figure 1 、 Figure 2 In [description of the figure], the present invention takes the valve body 1 as a carrier, and from top to bottom, it is composed of a handwheel rotating component, a valve cover component, and parts such as the valve stem 19, the gate plate 21, the valve seat 22, the sand control plate 25, and the guide plate 27, as well as the matching seals and connectors, forming a functional body for controlling the opening and closing of the pipeline channel.

[0016] In the middle of the valve body 1 is a columnar body with a cylindrical valve cavity blind hole processed. The left and right ends are protruding necked flanges, and the center of the flange is the left and right channel holes that vertically intersect with the valve cavity hole; at the intersection of the left and right channel holes and the cylindrical valve cavity hole, an installation hole for the valve seat 22 is enlarged; on the end faces of the left and right necked flanges, trapezoidal gasket grooves and evenly distributed stud holes are processed for external connection; on the upper surface of the columnar body of the valve body 1, trapezoidal gasket grooves and evenly distributed threaded blind holes are processed to connect the valve cover component with the sealing gasket ring 2 and the evenly distributed stud nuts 4.

[0017] The valve cover component of the present invention is composed of a valve cover 3, a combined seal 17, and a grease injection valve 20. The valve cover 3 is a component with a large end and a small end; the small end is a hollow stud body with a smaller diameter and a tool withdrawal groove, the large end is a hollow cylinder with a larger diameter, and a trapezoidal gasket groove and evenly distributed stud holes are machined under the large end; the center of the valve cover 3 has threaded holes and cylindrical holes with different diameters. The downward-facing small end has a threaded hole with a smaller diameter and a cylindrical stepped hole for installing the combined seal 17; the upward-facing large end has a large cylindrical hole with the same diameter as the valve cavity and a certain depth, which is used as an extension of the valve cavity; on the side wall of the large end of the valve cover 3, a stepped hole with tapered threads at the inlet is drilled, and a grease injection valve 20 is installed in the hole for injecting sealing grease into the valve to improve the sealing performance of the valve.

[0018] Figure 3 In this invention, the combined seal 17 is composed of a packing gland, a layer of metal gasket, four sealing rings with different cross-sections, and a layer of ⊥-shaped retaining ring stacked and combined; for the four sealing rings with different cross-sections, the top layer is a sealing ring with a square V-groove cross-section, the second layer is a sealing ring with a symmetric wing-shaped cross-section, the third layer is a composite sealing ring with a short-stem bell-shaped cross-section; the fourth layer is a composite sealing ring with a long-stem bell-shaped cross-section. When stacking: the V-groove under the top-layer sealing ring fits with the tip above the second-layer sealing ring, the V-groove and square groove under the second-layer sealing ring fit with the tip and short stem above the third-layer composite sealing ring, and the long stems above the fourth-layer composite sealing ring and the ⊥-shaped retaining ring are respectively inserted into the inner cavities below the bell-shaped cross-sections of the third-layer composite sealing ring and the fourth-layer composite sealing ring to seal the valve stem 19. In addition, to cope with ultra-high pressure working conditions, the entire body of the square V-groove cross-section sealing ring, the symmetric wing-shaped cross-section sealing ring, and the ⊥-shaped retaining ring in the combined seal 17, as well as the shells of the short-stem bell-shaped cross-section composite sealing ring and the long-stem bell-shaped cross-section composite sealing ring, are all molded from the special engineering plastic "polyether ether ketone, code: PEEK"; in the bell-shaped cross-section inner cavities of the short-stem bell-shaped cross-section composite sealing ring and the long-stem bell-shaped cross-section composite sealing ring, annular springs with a V-shaped cross-section whose tops are bent into arcs are installed; the annular springs are all stamped and welded from the non-magnetic alloy thin steel plate "Elgiloy".

[0019] In the valve cavity formed in the central holes of the valve body 1 and the valve cover assembly, a valve stem 19, a gate plate 21, and guide plates 27 located in front of and behind the gate plate 21 are installed from top to bottom; at the upper end of the gate plate 21, it is connected to the "T" - shaped joint at the lower end of the valve stem 19 by a "T" - shaped groove; on the flat surfaces on both the front and rear sides of the gate plate 21, long grooves that penetrate up and down are opened, and in the grooves, guide plates 27 formed by stamping thin steel plates are installed to prevent the gate plate 21 from shifting forward and backward. On both sides of the gate plate 21 in the valve cavity, valve seats 22 and their matching inner sealing rings 23 and outer sealing rings 24 are symmetrically installed; the cylindrical channel holes below the gate plate 21 and the channel holes on both sides of the valve seats 22 and the valve body 1 determine the opening or closing of the valve through the change of their relative positions. On both sides of the gate plate 21 and below the valve seats 22, a pair of anti - sand plates 25 with elastic rubber rings 26 are also symmetrically installed to prevent sand - containing media from entering the valve cavity.

[0020] Figure 4 and Figure 5 In and Figure 5 , the anti - sand plate 25 is a thick square steel plate with a flat surface on one side and an arc surface on the other side. Its flat surface is in contact with the gate plate 21, and its arc surface is in contact with the valve cavity hole in the valve body 1; there is an arc - shaped notch on the upper surface of the steel plate, which is used to connect with the valve seat 22; at the junction of the lower surface of the steel plate and the arc surface, there is a large chamfer for installation in the valve cavity; on the vertical bisectors of the flat surfaces and the arc surfaces on both sides of the anti - sand plate 25, near the arc - shaped notch, a small - diameter through - hole is drilled to balance the pressure inside and outside; on the arc surface of the anti - sand plate 25, below the arc - shaped notch, a square groove with four arc corners is symmetrically machined, and an elastic rubber ring 26 is installed in the square groove. After contacting the valve cavity hole wall, it will generate an elastic force to push the anti - sand plate 25 to closely fit with the gate plate 21. The elastic rubber ring 26 has a convex arc - shaped edge on the outer side of its cross - section, a semi - circular groove on the inner side, and the other two sides are parallel straight edges; the elastic rubber ring 26 is made of "FKM fluororubber" or "HNBR highly saturated hydrogenated nitrile rubber" material as a whole to cope with harsh working conditions.

[0021] In addition, to cope with ultra - high - pressure working conditions, the inner sealing ring 23 and the outer sealing ring 24 that are matched with the valve seat 22 of the present invention are both a composite elastic sealing ring: the radial cross - section of its outer main ring is in a U - shape, and it is molded by a special engineering plastic "polyether ether ketone, code: PEEK"; inside the U - shaped opening of the main ring, a metal spring ring with a radial cross - section in a V - shape is contained; inside the V - shaped metal spring ring, a polymer material ring with a radial cross - section in a rectangle and chamfered on four sides is contained. The differences between the inner sealing ring 23 and the outer sealing ring 24 are: one is the different diameters; the other is that the U - shaped main ring opening of the inner sealing ring 23 faces inward, and the U - shaped main ring opening of the outer sealing ring 24 faces outward.

[0022] Above the upper end of the valve body 1 and above the valve cover assembly, there is a handwheel rotating component. The handwheel rotating component consists of a bearing housing 5, a locking mechanism 6, a rotating shaft sleeve 7, a handwheel 8, a transparent shield 9, an oil cup 10, a ball screw pair 11, socket head cap screws 12, screw washers 13, O-ring seals 14, thrust bearings 15, and set screws 18. On the upper and lower surfaces of the raised shoulder of the lower part of the rotating shaft sleeve 7, one thrust bearing 15 is installed on each side. After being wrapped by the bearing housing 5 and the O-ring seal 14, the threaded hole on the bottom surface of the bearing housing 5 is connected to the stud body at the upper end of the valve cover 3, and then fixed with the set screw 18. The handwheel 8 is installed at the hexagonal prism at the upper part of the rotating shaft sleeve 7 with the hexagonal hole in the hub center. The nut of the ball screw pair 11 is installed in the central hole at the upper end of the rotating shaft sleeve 7 and then fixed together with evenly distributed socket head cap screws 12. The transparent shield 9 is sleeved on the upper end of the ball screw pair 11 and fixed on the hub of the handwheel 8 with evenly distributed screw washers 13. The transparent shield 9 is made of engineering plastics, and on the surface of its cylinder, there are engraved words "Open, Close" and percentage graduation lines, which cooperate with the shaft end retaining ring at the upper end of the ball screw pair 11 to display the opening and closing conditions of the valve. The ball screw pair 11 adopts the structure of an internal circulation series and a necked flange type nut: in the central hole of its nut, there are circulating rolling steel balls and a screw shaft. At the upper end of the screw shaft, there is a shaft end retaining ring fixed with a screw washer to prevent the nut and the internal steel balls from slipping off; at the lower end of the screw shaft, there is a cylinder with a radial pin hole and a screw head. After being connected to the upper end of the valve stem 19 with threads and a cylindrical pin 16, the rotational torque on the handwheel 8 can be converted into the driving force for the up and down movement of the gate plate 21 through the ball screw pair 11 and the valve stem 19.

[0023] Figure 6 In order to prevent the ball screw pair 11 without self-locking ability from automatically rotating to open the valve, and at the same time prevent the deviation of the gate plate 21 from affecting the sealing performance of the inner sealing rings 23 and outer sealing rings 24 on both sides of the valve seat 22; in the present invention, a blind hole is drilled on the circumferential edge of the raised shoulder at the lower part of the rotating shaft sleeve 7. In the threaded hole on one side of the bearing housing 5 corresponding to the blind hole, a manually controllable locking mechanism 6 is installed and welded firmly. When the plug in the locking mechanism 6 is docked and locked with the blind hole on the shoulder of the rotating shaft sleeve 7, it can not only prevent the handwheel 8 and the ball screw pair 11 from rotating self, but also leave a floating gap for the gate plate 21 after closing the valve.

[0024] The locking mechanism 6 of the present invention is composed of an elastic bolt 601, a fixed sleeve 602, a compression spring 603, a slotted nut 604, a pull ring 605 and a set screw 606. The fixed sleeve 602 is a relatively thin steel pipe, and the two ends of the steel pipe are processed with external threads. One end is connected to the threaded hole on one side of the bearing housing 5 and fixed by welding, and the other end is connected to the slotted nut 604 and fixed by the set screw 606; inside the central hole of the fixed sleeve 602, an elastic bolt 601 and a compression spring 603 are installed; the thick end of the elastic bolt 601 faces inward, and the thin end passes through the central holes of the compression spring 603 and the slotted nut 604, and then the pull ring 605 is used to buckle the radial small hole at the thin end to form an integral small component. The periphery of the slotted nut 604 can be processed into a hexagonal prism or a knurled cylinder for easy assembly; the inner end of it is processed with a threaded hole with a relief groove and is connected to the fixed sleeve 602; a radial small threaded hole is drilled on the circumferential wall of the threaded hole for installing the set screw 606; the outer end of it is processed with a small through hole to allow the thin end of the elastic bolt 601 to pass through and block the compression spring 603; on the center line of the outer end face of the small through hole, a deep and a shallow cross groove are processed for cooperating with the pull ring 605. When the elastic bolt 601 and the pull ring 605 are rotated 90 degrees and placed in the deep groove, they will automatically find the blind hole to lock; when the elastic bolt 601 and the pull ring 605 are pulled out and rotated 90 degrees and placed in the shallow groove for positioning, the handwheel 8 and the ball screw pair 11 will be allowed to operate normally.

[0025] The above shows and describes the basic principles, main features and main advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above-described embodiments, especially the individual components or the combined seals 17 and the elastic rubber rings 26. Without departing from the spirit and scope of the present invention, any changes and improvements in shape or material are within the scope of the protection requirements of the present invention.

Claims

1. A super high pressure sand control type open stem flat valve driven by a ball screw, which is composed of a handwheel rotating component, a valve cover component, a valve body, a valve stem, a gate plate, a valve seat, a sand control plate, a guide plate part, as well as supporting seals and connectors; characterized in that: Above the valve cover component and the valve stem part, there is a handwheel rotating component. Inside the handwheel rotating component, there is a ball screw pair connected to the valve stem. On one side of the handwheel rotating component, a locking mechanism that allows or prohibits the rotation of the handwheel and the screw nut is added; at the upper end of the valve body, at the contact between the central hole of the valve cover component and the valve stem, there is a set of combined seals composed of multiple layers of non-rubber seals with different cross-sections stacked; in the cylindrical valve cavity of the valve body, below the valve seat, a pair of anti-sand plates filled with the valve cavities on both sides of the gate plate and with elastic rubber rings are symmetrically installed; the locking mechanism is composed of an elastic bolt, a fixed sleeve, a compression spring, a slotted nut, a pull ring and a set screw; the fixed sleeve is a thinner steel pipe, and external threads are processed at both ends of the steel pipe; inside the central hole of the fixed sleeve, an elastic bolt and a compression spring are installed; the thick end of the elastic bolt faces inward, and the thin end passes through the central holes of the compression spring and the slotted nut, and then the thin end radial small hole is buckled by the pull ring to form an integral small component; the periphery of the slotted nut can be processed into a hexagonal prism or a knurled cylinder, the inward end is processed with a threaded hole with a relief groove, a radial small threaded hole is drilled on the circumferential wall of the threaded hole, the outward end is processed with a small through hole, and a deep and a shallow cross groove are processed on the center line of the outer end face of the small through hole.

2. The ball screw driven ultra-high pressure sand control type open stem flat valve without tail rod according to claim 1, characterized in that: The combined seal is composed of a packing gland, a layer of metal washer, four seals with different cross-sections and a layer of ⊥-shaped retaining ring stacked and combined; among the four seals with different cross-sections, the top layer is a seal with a square V-groove cross-section, the second layer is a seal with a symmetric wing-shaped cross-section, and the third layer is a composite seal with a short-stem bell-shaped cross-section; the fourth layer is a composite seal with a long-stem bell-shaped cross-section.

3. The ball screw driven ultra-high pressure sand control type open stem flat valve without tail rod according to claim 2, characterized in that: The whole body of the square V-groove cross-section seal, the symmetric wing-shaped cross-section seal and the ⊥-shaped retaining ring in the combined seal, and the shells of the short-stem bell-shaped cross-section composite seal and the long-stem bell-shaped cross-section composite seal are all molded from "polyether ether ketone" special engineering plastics; inside the bell-shaped cross-section inner cavities of the short-stem bell-shaped cross-section composite seal and the long-stem bell-shaped cross-section composite seal, annular springs with the top bent into an arc and a V-shaped cross-section are installed; the annular springs are all stamped and welded from "Elgiloy" non-magnetic alloy thin steel plates.

4. The ball screw driven ultra-high pressure sand control type open stem flat valve without tail rod according to claim 1, characterized in that: The anti-sand plate is a square thick steel plate with a flat side and an arc side on one side. There is an arc-shaped notch on the upper surface of the steel plate, and a large chamfer is at the intersection of the lower surface of the steel plate and the arc side; on the perpendicular bisectors of the flat side and the arc side of both sides of the anti-sand plate, near the arc-shaped notch, a small-diameter through hole is drilled; on the arc surface of the anti-sand plate, below the arc-shaped notch, a square groove with four arc corners is symmetrically processed.

5. The ball screw-driven ultra-high pressure sand control type open stem flat valve without tail rod according to claim 1, characterized in that: The elastic rubber ring has a convex arc edge on the outer side of its cross-section, a semi-circular groove on the inner side, and the other two sides are parallel straight edges; the elastic rubber ring is made of "FKM fluororubber" or "HNBR high-saturation hydrogenated nitrile rubber" material as a whole.

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