A straight-through lift check valve

Abstract

A straight-through lift check valve utilizes the forged body and bonnet blanks of existing high-pressure or ultra-high-pressure lift check valves, along with matching seals and connectors. The valve cavity within the valve body is a square, rounded-corner blind hole cavity, with the inlet and outlet openings of the valve body extending perpendicularly through the blind hole cavity. An integrated valve seat is welded to the inner end of the valve body's inlet passage. An inclined hole is drilled between the valve cavity and the outlet opening. Within the valve body, bonnet, and the valve cavity, which is sealed with a sealing gasket and stud nut, is a valve core assembly with a guide rod and compression spring in an elliptical recess above, an inclined surface below, a flat surface with four telescopic pins on the left, and a sealing plug on the right. Furthermore, the integrated valve seat and the sealing plug on the right side of the valve core are welded with high-nickel-chromium-molybdenum alloy ER625. Compared to commonly used high-pressure or ultra-high-pressure lift check valves, this valve core assembly offers unobstructed flow, reduced energy consumption, and is economical and durable.

Description

Technical Field

[0001] The invention relates to a one-flow valve in industrial machinery, fluid equipment or pipelines. Background Art

[0002] At present, various check valves are used in fluid equipment or pipelines, and high-pressure or ultra-high-pressure lift check valves are often used in oil and gas drilling equipment and well-killing manifolds. Their flow paths are tortuous and changeable, and there are right-angle turns, so the flow resistance is large and the energy consumption is high. In addition, under the erosion of ultra-high-pressure sand-containing media, the parts wear quickly and the service life is short, which is not conducive to reducing the cost of oil and gas extraction. Summary of the Invention

[0003] The present invention redesigns the existing lift check valve based on the principles of fluid mechanics, and provides a lift check valve with a full-diameter, straight-through channel suitable for high-pressure or ultra-high-pressure working conditions.

[0004] The present invention adopts the forged blanks of the valve body and valve cover of the existing high-pressure or ultra-high-pressure lift-type check valve, as well as matching seals and connectors; the differences are as follows: the valve cavity in the valve body is a blind hole valve cavity with a square rounded cross-section, and the inlet and outlet channel holes of the valve body are vertically connected to the blind hole valve cavity; an integrated valve seat is welded on the inner end of the valve body inlet channel; an inclined hole is drilled between the valve cavity and the outlet channel hole; and a valve core assembly is installed in the valve body, valve cover and the valve cavity sealed by a sealing gasket and stud nut. The assembly has an elliptical pit on the upper side with a guide rod and a compression spring, an inclined surface on the lower side, a flat surface with four telescopic pins on the left side, and a sealing plug on the right side.

[0005] The material of the surfacing integrated valve seat is high nickel chromium molybdenum alloy ER625. High nickel chromium molybdenum alloy ER625 is also surfacing welded on the annular inclined surface or arc surface of the sealing plug on the right side of the valve core.

[0006] Because the present invention incorporates a uniquely structured valve core assembly within a closed valve chamber, during operation, the inclined surface below the valve core, with its larger surface area than the flat surface above, generates an upward force. Furthermore, the inclined hole between the valve chamber and the outlet passageway directs flow, causing the fluid velocity above the valve core to be greater than that below, resulting in a pressure differential and upward lift. Under the combined action of these factors, the valve core first moves leftward, clearing the integrated valve seat. Then, overcoming the thrust of the compression spring and the frictional resistance of the telescopic pins, it moves upward until it completely clears the inlet and outlet passageways, ensuring unobstructed flow. When pressure in the inlet passageway disappears, the valve core rapidly moves downward under the thrust of the compression spring and, driven by the four telescopic pins and the pressure of the return fluid, seals against the integrated valve seat. This results in a large flow area, low flow resistance, minimal valve core wear, and a long service life. Furthermore, the integrated valve seat and the sealing plug on the right side of the valve core are welded with high-nickel-chromium-molybdenum alloy ER625, which offers superior wear and erosion resistance. This extends the product's service life and improves user efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a full cross-sectional diagram of the overall structure of a commonly used lift check valve;

[0008] Figure 2 This is a schematic cross-sectional view of the overall structure of the valve of the present invention when it is closed;

[0009] Figure 3 yes Figure 2 After the valve cover is removed, the A direction has an enlarged schematic diagram of the partial cross-section structure;

[0010] Figure 4 yes Figure 2 Center B direction, enlarged schematic diagram of the left side structure of the valve core parts.

[0011] The names of the parts indicated by the numbers in the accompanying drawings are as follows:

[0012] 1. Valve body, 2. Integrated valve seat, 3. Valve core, 4. Guide rod, 5. Compression spring, 6. Valve cover, 7. Sealing ring, 8. Stud nut, 9. Oblique hole, 10. Small spring, 11. Telescopic pin. DETAILED DESCRIPTION

[0013] The present invention will be further described below in conjunction with the accompanying drawings:

[0014] The present invention adopts the forging blanks of the valve body and valve cover of the existing high-pressure or ultra-high-pressure lift-type check valve, as well as the matching seals and connecting parts; and redesigns and processes part of the structure and internal parts of the valve body and valve cover forgings, which can reduce production costs and improve production efficiency.

[0015] The valve body 1 of the present invention is a three-way component, with a cylinder in the middle and neck flanges extending from the left and right ends for external connection. Inside the middle cylinder, a blind hole valve cavity of the same size and square rounded corner cross-section is machined from top to bottom. The upper end face of the middle cylinder is machined with a trapezoidal gasket groove and evenly distributed threaded blind holes for connecting to the valve cover 6. The centers of the left and right neck flanges are respectively machined into inlet and outlet channel holes of the same diameter and axis, which are vertically connected to their blind hole valve cavities. Both end faces of the neck flanges are machined with a trapezoidal gasket groove and evenly distributed stud holes for external connection. An inclined hole 9 is drilled between the blind hole valve cavity and the outlet channel hole of the valve body 1 for diversion and pressure relief. The fluid medium of the present invention enters from the inlet channel hole in the center of the neck flange on the right side of the valve body 1, passes through the integrated valve seat 2, pushes the valve core 3 upward, and is discharged from the outlet channel hole in the center of the neck flange on the left side.

[0016] The integrated valve seat 2 of this invention is made of corrosion-resistant and wear-resistant hard alloy and is directly overlay-welded to the inner port of the valve body 1's inlet passage. Compared to traditional, standalone, inlaid valve seats, it offers the advantages of lower cost and improved sealing. The overlay-welded integrated valve seat 2 is made of ER625, a high-nickel-chromium-molybdenum alloy. After machining, the integrated valve seat 2 has a wall thickness of greater than or equal to 3 mm to ensure its service life.

[0017] The valve core 3 of the present invention is an irregular square part, and its four sides are slidably matched with the blind hole valve cavity of the square rounded cross-section of the valve body 1 to prevent it from deviating from the integrated valve seat 2 when it moves downward; an elliptical pit for installing the guide rod 4 and the compression spring 5 is processed on the valve core 3, and there is an inclined surface below, a plane with four telescopic pins 11 on the left, and a sealing plug on the right; on the top and bottom of the valve core 3, except for the sealing plug on the right, the corners can be appropriately chamfered or processed into rounded corners; on the plane on the left side of the valve core 3, at the exit relative to the valve body 1, Four symmetrical small blind holes of the same depth are drilled on both sides of the orifice hole. Four small springs 10 and telescopic pins 11 of the same size are installed in the small blind holes to push the valve core 3 to match the integrated valve seat 2; on the vertical bisector of the left plane, a drain hole is also drilled that communicates with the bottom of the elliptical pit on the valve core to prevent sand and dust from clogging; on the annular inclined surface or arc surface of the sealing plug on the right side of the valve core 3, high nickel-chromium-molybdenum alloy ER625 material is welded. The thickness of the weld layer after cutting should be greater than or equal to 2.5 mm to make it durable.

[0018] The guide rod 4 of the present invention has a cone at the upper end, a shoulder at the lower end, and a cylinder in the middle. It is inserted into the lower end of the compression spring 5 and installed together in the elliptical pit above the valve core 3. When the valve core 3 moves up and down, the guide rod 4 slides a small amount left and right in the elliptical pit to prevent the compression spring 5 from becoming unstable under the action of radial force.

[0019] The compression spring 5 of the present invention is a conventional spring component, and its steel wire is relatively thin. Its elastic force is sufficient to push the valve core 3 to overcome the friction resistance of the telescopic pin 11 and quickly return to its original position.

[0020] The valve cover 6 of the present invention is provided with a flow direction mark of the check valve on its upper surface, and is processed with a trapezoidal gasket ring groove, a boss and a central blind hole on its lower surface. The periphery thereof is processed with evenly distributed stud holes so that it can be connected and fixed to the upper surface of the valve body 1 by using a sealing gasket 7 and a stud nut 8; the central blind hole under the valve cover 6 is sleeved on the upper end of the compression spring 5 to prevent its displacement.

Claims

1. A straight-through lift check valve, using the forged blanks of the valve body and valve cover of an existing high-pressure or ultra-high-pressure lift check valve, as well as matching seals and connectors; characterized by: The valve cavity within the valve body is a blind hole cavity with a square, rounded cross-section. The inlet and outlet passages of the valve body extend perpendicularly through the blind hole cavity. An integrated valve seat is welded to the inner end of the inlet passage of the valve body. An inclined hole is drilled between the valve cavity and the outlet passage. A valve core assembly, containing a guide rod and compression spring in an elliptical pit on the upper side, an inclined surface on the lower side, a flat surface with four telescopic pins on the left side, and a sealing plug on the right side, is installed within the valve body, bonnet, and the valve cavity, which is sealed with a sealing gasket and stud nut. The valve core is an irregular square component, with its four sides slidingly engaged with the blind hole cavity of the square, rounded cross-section of the valve body. Four symmetrical small blind holes of the same depth are drilled on the left side of the flat surface of the valve core, on either side of the outlet passage of the valve body. Four small springs of the same size and telescopic pins are installed in these small blind holes. A drain hole is also drilled on the perpendicular bisector of the left flat surface, communicating with the bottom of the elliptical pit on the upper side of the valve core.

2. The straight-through lift check valve according to claim 1, characterized in that: The material of the surfacing integrated valve seat is: high nickel chromium molybdenum alloy ER625, and the wall thickness of the integrated valve seat after cutting is greater than or equal to 3 mm.

3. The straight-through lift check valve according to claim 1 is characterized in that: The annular inclined surface or arc surface of the sealing plug on the right side of the valve core is welded with high nickel-chromium-molybdenum alloy ER625 material, and the thickness of the weld layer after cutting should be greater than or equal to 2.5 mm.

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