A forced sealing ball valve with reliable operation

Abstract

A reliable forced sealing ball valve comprises a valve body, a valve cover, a valve stem and a ball. The ball is arranged in a flow channel of the valve body, a valve seat is arranged between the ball and the valve body, the top of the valve body is sealed by the valve cover, the valve stem passes through the valve cover and is connected with the top of the ball, and a bracket is also arranged at the top of the valve cover, characterized in that: a ball pin is arranged at the connection between the valve stem and the ball; two guide grooves are symmetrically arranged on the side wall of the lower half of the valve stem, and the guide grooves are arranged in a spiral shape along the side wall of the valve stem; a limit pin is arranged on the valve cover corresponding to the guide groove, the inner end of the limit pin passes through the side wall of the valve cover and is embedded in the guide groove and can slide along the guide groove, and a grease injection channel is arranged from the outer end to the inner end of the limit pin; an upper bearing is arranged between the valve stem and the bracket, a packing is arranged between the valve stem and the top of the valve cover, the packing is sealed by a packing gland, and a middle bearing is arranged below the packing; a lower bearing is arranged between the valve stem and the valve cover below the limit pin; a downstream flow channel hole is arranged at the lower part of the outlet end of the flow channel of the valve body, and a valve cavity flow channel hole is arranged in the valve body below the ball.

Description

Technical Field

[0001] The invention relates to the field of valves, and in particular to a forced sealing ball valve with reliable operation. Background Art

[0002] With the rapid development of domestic oil and gas pipeline construction, the demand for key equipment of oil and gas pipelines has also increased dramatically. As one of the key equipment of oil and gas pipelines, forced sealing ball valves are widely used in harsh working conditions with large operating pressure difference, frequent switching, pressure and temperature difference requiring valves to maintain good sealing for a long time, and frequent shutdown for maintenance and replacement of valves are not allowed. Forced sealing ball valves belong to multi-mechanism transmission control valve opening and closing, and each transmission part will be affected by factors such as the force of the actuator and the force of the pipeline medium. The reliability of the action of each transmission part is crucial to the safe operation of the entire valve, especially for key stress-bearing parts. At present, conventional forced sealing ball valves at home and abroad have the following disadvantages:

[0003] 1. The overall height is relatively high. The length of the valve stem of large valves reaches more than 2 meters. The concentricity of the valve body, valve cover and bracket cannot be effectively controlled. The valve stem often has eccentric movement at the top during opening and closing. This phenomenon may cause increased wear and torque of the valve stem at the least, or serious obstruction of the valve stem and inability to move the valve at the worst.

[0004] 2. There is a linear contact between the ball pin and the valve stem. The ball pin itself is not hard enough. Long-term switching of the valve can easily cause the ball pin to deform, causing the valve stem to be eccentric, affecting the sealing performance and even causing valve leakage.

[0005] 3. There is no cleaning and discharge function for water or impurities accumulated in the valve body. If the valve is in a closed state for a long time, the accumulated water will freeze or impurities will accumulate at low temperatures, which will affect the movement of the ball. In severe cases, the ball will be seriously blocked and the valve will not be able to move. Summary of the invention

[0006] To solve the above problems, the present invention provides the following solutions:

[0007] A reliable forced sealing ball valve comprises a valve body, a valve cover, a valve stem and a ball. The ball is arranged in the flow channel of the valve body, a valve seat is arranged between the ball and the valve body, the top of the valve body is sealed by the valve cover, the valve stem passes through the valve cover and is connected to the top of the ball, a bracket is also arranged at the top of the valve cover, and a ball pin is arranged at the connection between the valve stem and the ball; two guide grooves are symmetrically arranged on the side wall of the lower half of the valve stem, and the guide grooves are arranged in a spiral shape along the side wall of the valve stem, and the valve cover is provided with a limit pin corresponding to the guide groove, the inner end of the limit pin passes through the side wall of the valve cover and is embedded in the guide groove, and can slide along the guide groove, and a grease injection channel is arranged from the outer end to the inner end of the limit pin; an upper bearing is arranged between the valve stem and the bracket, a packing is arranged between the valve stem and the top of the valve cover, the packing is sealed by a packing gland, and a middle bearing is arranged below the packing; the upper, middle and lower bearings form a three-point positioning valve stem structure. A lower bearing is arranged between the valve stem and the valve cover below the limit pin; a downstream flow channel hole is arranged at the lower part of the outlet end of the flow channel of the valve body, and a valve cavity flow channel hole is arranged in the valve body below the ball.

[0008] Furthermore, a grease injection valve is provided at the outer end of the grease injection channel.

[0009] Furthermore, the downstream flow channel hole is connected to a downstream flow channel pipe, the valve cavity flow channel hole is connected to a valve cavity flow channel pipe, the valve cavity flow channel pipe and the downstream flow channel pipe are connected in parallel and then connected to a main pipe, and valves are arranged on the main pipe, the valve cavity flow channel pipe and the downstream flow channel pipe.

[0010] Furthermore, the valve is a ball valve.

[0011] Furthermore, the upper bearing, the middle bearing and the lower bearing are all copper sleeve bearings.

[0012] Furthermore, a first inclined surface is opened inside one side of the lower end of the valve stem, a vertical plane is formed from the first inclined surface to the bottom end of the valve stem, a groove is opened inwardly on the side of the lower end of the valve stem opposite to the first inclined surface, a second inclined surface is formed from the groove to the side wall of the valve stem, and a ball pin plane is arranged on the side wall of the ball pin corresponding to the first inclined surface and the second inclined surface, and the ball pin plane is in contact with the first inclined surface and the second inclined surface plane.

[0013] Furthermore, sealing rings are provided between the middle bearing and the valve stem, and between the middle bearing and the valve cover.

[0014] Furthermore, the sealing ring is an O-ring.

[0015] The beneficial effects of the present invention are:

[0016] 1. The support of each point of the valve stem ensures the reliability of the valve stem operation, especially for frequent switching conditions. The valve stem always switches repeatedly within a fixed range of motion, which reduces the wear of the valve stem, limit pin, ball pin and other contact parts and controls the uniformity of friction, which plays a key role in improving the reliability of valve sealing and the life of valve operation. Therefore, the multi-point positioning structure is advanced both at home and abroad.

[0017] 2. By setting up a pipeline for cleaning and discharging water or impurities in the valve cavity, the influence of water freezing or impurity accumulation on the movement of the ball is avoided, and the reliability of valve operation is improved.

[0018] 3. By increasing the pressure area of ​​the ball pin, the pressure resistance of the ball pin is greatly improved, avoiding the eccentricity or jamming of the valve stem caused by the deformation of the ball pin under the pressure of the valve stem. The hardening treatment of the key components, the ball pin and the limit pin, greatly improves the mechanical properties of the material such as strength, toughness, fatigue strength, etc., which plays a key role in improving the reliability of the valve switch action and the reliability of the seal.

[0019] 4. The grease injection valve on the limit pin can be used to regularly inject lubricating oil into the valve stem to reduce the movement friction between the valve stem and the limit pin, effectively ensuring the reliability of the valve action. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the present invention;

[0021] Figure 2 for Figure 1 Schematic diagram of the structure of part A;

[0022] Figure 3 for Figure 1 Schematic diagram of the structure of part B.

[0023] 1. Valve body; 2. Valve cover; 3. Bracket; 4. Ball; 5. Valve seat; 6. Valve stem; 7. Ball pin; 8. Limit pin; 9. Packing gland; 10. Packing; 11. Upper bearing; 12. Middle bearing; 13. Lower bearing; 14. Grease injection valve; 15. Valve cavity flow channel hole; 16. Downstream flow channel hole; 17. Ball valve; 18. Grease injection channel; 19. Guide groove; 20. Groove; 21. First inclined surface; 22. Second inclined surface. DETAILED DESCRIPTION

[0024] The present invention is now described in detail with reference to the accompanying drawings:

[0025] Example 1: Figure 1 , Figure 2 and Figure 3A forced sealing ball valve with reliable operation comprises a valve body 1, a valve cover 2, a valve stem 6 and a ball 4. The ball 4 is arranged in the flow channel of the valve body 1, a valve seat 5 is arranged between the ball 4 and the valve body 1, the top of the valve body 1 is sealed by the valve cover 2, the valve stem 6 passes through the valve cover 2 and is connected with the top of the ball 4, a bracket 3 is also arranged at the top of the valve cover 2, and a ball pin 7 is arranged at the connection between the valve stem 6 and the ball 4; two guide grooves 19 are symmetrically provided on the side wall of the lower half of the valve stem 6, and the guide grooves 19 are arranged in a spiral shape along the side wall of the valve stem 6, and the valve cover 2 is provided with a limit pin 8 corresponding to the guide groove 19, and the limit pin 8 is provided. The inner end of the pin 8 passes through the side wall of the valve cover 2 and is embedded in the guide groove 19, and can slide along the guide groove 19. A grease injection channel 18 is opened from the outer end to the inner end of the limit pin 8; an upper bearing 11 is arranged between the valve stem 6 and the bracket 3, a packing 10 is arranged between the valve stem 6 and the top of the valve cover 2, the packing 10 is covered by a packing gland 9, and a middle bearing 12 is arranged below the packing 10; a lower bearing 13 is arranged between the valve stem 6 and the valve cover 2 below the limit pin 8; a downstream flow channel hole 16 is opened at the lower part of the downstream end of the flow channel of the valve body 1, and a valve cavity flow channel hole 15 is opened in the valve body 1 below the ball 4.

[0026] The outer end of the grease injection channel 18 is provided with a grease injection valve 14. The downstream flow channel hole 16 is connected to the downstream flow channel pipe, and the valve cavity flow channel hole 15 is connected to the valve cavity flow channel pipe. The valve cavity flow channel pipe and the downstream flow channel pipe are connected in parallel and connected to the main pipe. The main pipe, the valve cavity flow channel pipe and the downstream flow channel pipe are all provided with valves. The valve is a ball valve 17. The upper bearing 11, the middle bearing 12 and the lower bearing 13 are all copper sleeve bearings.

[0027] A first inclined surface 21 is formed inwardly on one side of the lower end of the valve stem 6, and a vertical plane is formed from the first inclined surface 21 to the bottom end of the valve stem 6. A groove 20 is formed inwardly on one side of the lower end of the valve stem 6 opposite to the first inclined surface 21, and a second inclined surface 22 is formed from the groove 20 to the side wall of the valve stem 6. A ball pin plane is provided on the side wall of the ball pin 7 corresponding to the first inclined surface 21 and the second inclined surface 22, and the ball pin plane is in contact with the first inclined surface 21 and the second inclined surface 22.

[0028] An upper bearing 11 is arranged between the valve stem 6 and the bracket 3; a middle bearing 12 is arranged between the valve stem 6 and the valve cover 2, and an O-ring is arranged between the middle bearing 12, the valve cover 2 and the valve stem 6 to prevent leakage of the medium; a lower bearing 13 is arranged between the lower part of the valve stem 6 and the valve cover 2, and the upper bearing 11, the middle bearing 12 and the lower bearing 13 form a three-point positioning valve stem structure. The valve stem 6 is subjected to overall aging treatment, and the overall wear resistance of the valve stem 6 is improved. The upper bearing 11, the middle bearing 12 and the lower bearing 13 are copper sleeve bearings, which have good lubricity and are easy to deform, and make up for the gap caused by the concentricity deviation of each assembly, ensuring that the valve stem 6 will not be blocked during the switching process, and ensuring the reliability of the valve operation.

[0029] The inner end of the limit pin 8 is placed in the guide groove 19 of the valve stem 6, leaving a certain gap with the bottom of the guide groove 19. When the valve is switched, the limit pin 8 and the guide groove 19 generate motion friction. The limit pin 8 undergoes multiple hardening processes during the production process. At the same time, a grease injection valve 14 is provided on the limit pin 8, and a grease injection channel 18 is provided in the center of the limit pin 8, which can regularly inject lubricating oil into the guide groove 19, thereby reducing the motion friction between the limit pin 8 and the valve stem 6. The hardening treatment of the limit pin 8 from the inside to the outside greatly improves its friction resistance and fatigue resistance, and ensures the reliability of the valve operation.

[0030] The ball pin 7 is arranged on the ball body 4, and the lower end of the valve stem 6 is between the two ball pins 7. The side wall of the lower end of the valve stem has a groove 20, and the bottom surface of the groove 20 is a plane. The side wall of the ball pin 7 is divided into a plane corresponding to the bottom surface of the groove 20. The plane of the ball pin 7 contacts the bottom surface of the groove 20, and the contact is a plane contact. During the operation of the valve, the ball pin 7 is subjected to the force of the valve stem 6, so that the ball body 4 moves to open and close the valve. As a key component, the ball pin 7 undergoes multiple hardening processes during the production and processing. At the same time, the ball pin 7 and the valve stem 6 are arranged in plane contact, which increases the force area of ​​the ball pin 7, improves the comprehensive performance of the ball pin 7 in terms of pressure resistance, fatigue resistance, and wear resistance, and ensures the reliability of the valve operation.

[0031] A valve cavity flow channel 15 hole is arranged at the lowest position of the valve body 1 cavity to communicate with the upstream medium, and a downstream flow channel hole 16 is arranged on the bottom surface of the valve body 1 at the downstream end of the flow channel to communicate with the downstream medium. The valve cavity flow channel hole 15 and the downstream flow channel hole 16 are connected by a pipeline and a ball valve 17 is arranged in the middle. When the valve is in a closed state, the accumulated water or impurities generated upstream enter the valve body 1 cavity. Since the valve is in a closed state, if the ball valve 17 on the valve cavity flow channel pipe and the ball valve 17 on the downstream flow channel pipe are opened at this time, and the ball valve 17 of the main pipe is closed, the upstream pressurized medium will push the accumulated water or impurities into the valve cavity flow channel pipe through the valve cavity flow channel hole, and flow out from the downstream flow channel hole 16 and into the downstream flow channel pipe; if the ball valve 17 on the valve cavity flow channel pipe and the ball valve 17 of the main pipe are opened at this time, and the ball valve 17 of the downstream flow channel pipe is closed, the upstream pressurized medium will push the accumulated water or impurities into the valve cavity flow channel pipe through the valve cavity flow channel hole 15 and flow out from the main pipe. When there is also some water or impurities in the downstream, in order to prevent the water or impurities from entering the cavity of the valve body 1 when the valve is opened, the ball valve 17 of the downstream flow channel pipe and the ball valve 17 of the main pipe can be opened, and the ball valve 17 of the valve cavity flow channel pipe can be closed. The pressurized medium in the downstream will push the water or impurities into the downstream flow channel pipe from the downstream flow channel hole 16 and flow out from the ball valve 17 of the main pipe. Regularly cleaning and discharging the water or impurities in the valve cavity prevents the accumulation of impurities or the freezing of water at low temperatures from affecting the movement of the ball, ensuring the reliability of the valve movement.

[0032] Many variations and improvements can be made according to the inventive spirit and principles of the present invention. Therefore, the above example is only one of the explanations of the inventive ideas, principles and implementation methods of the device of the present invention. The content of this specification should not be a limitation of the invention. For those skilled in the art, various variations and improvements made without changing the basic working principles and the concept of the present invention should be regarded as within the scope of protection of the invention.

Claims

1. A reliable forced sealing ball valve, comprising a valve body, a valve cover, a valve stem, and a ball. The ball is arranged in the flow channel of the valve body, a valve seat is arranged between the ball and the valve body, the top of the valve body is sealed by the valve cover, the valve stem passes through the valve cover and is connected to the top of the ball, and a bracket is also arranged on the top of the valve cover, characterized in that: A ball pin is provided at the connection between the valve stem and the ball; a first inclined surface is provided inwardly on one side of the lower end of the valve stem, and a vertical plane is formed from the first inclined surface to the bottom end of the valve stem; a groove is provided inwardly on one side of the lower end of the valve stem opposite to the first inclined surface, and a second inclined surface is formed from the groove to the side wall of the valve stem; a ball pin plane is provided on the side wall of the ball pin corresponding to the first inclined surface and the second inclined surface, and the ball pin plane contacts the first inclined surface and the second inclined surface plane; The side wall of the lower half of the valve stem is symmetrically provided with two guide grooves, which are arranged in a spiral shape along the side wall of the valve stem. The valve cover is provided with a limit pin corresponding to the guide groove. The inner end of the limit pin passes through the side wall of the valve cover and is embedded in the guide groove and can slide along the guide groove. A grease injection channel is provided from the outer end to the inner end of the limit pin. An upper bearing is arranged between the valve stem and the bracket, a packing is arranged between the valve stem and the top end of the valve cover, the packing is sealed by a packing gland, and a middle bearing is arranged below the packing; A lower bearing is arranged between the valve stem and the valve cover below the limit pin; a downstream flow channel hole is arranged at the lower part of the outlet end of the valve body flow channel, and a valve cavity flow channel hole is arranged at the valve body below the ball; The downstream flow channel hole is connected to a downstream flow channel pipe, the valve cavity flow channel hole is connected to a valve cavity flow channel pipe, the valve cavity flow channel pipe and the downstream flow channel pipe are connected in parallel and then connected to the main pipe, and valves are arranged on the main pipe, the valve cavity flow channel pipe and the downstream flow channel pipe.

2. A reliable forced sealing ball valve as claimed in claim 1, characterized in that: A grease injection valve is arranged at the outer end of the grease injection channel.

3. A reliable forced sealing ball valve as claimed in claim 1, characterized in that: The valve is a ball valve.

4. A reliable forced sealing ball valve as claimed in claim 1, characterized in that: The upper bearing, the middle bearing and the lower bearing are all copper sleeve bearings.

5. A reliable forced sealing ball valve as claimed in claim 1, characterized in that: Sealing rings are arranged between the middle bearing and the valve stem, and between the middle bearing and the valve cover.

6. A reliable forced sealing ball valve as claimed in claim 5, characterized in that: The sealing ring is an O-ring.

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