A pre-tightening sealed ball valve device

Abstract

The application relates to the technical field of valves, in particular to a pre-tightening sealing ball valve device; the device comprises a shell, a control system, a valve ball, sealing rings and a valve rod, two sealing grooves are arranged in the shell, the two sealing rings are respectively fixedly installed in the sealing grooves, a sealing gasket is arranged between the sealing rings and the valve ball, an adjusting gasket is arranged between the adjusting ring and the sealing groove, an installation hole is formed in the valve ball, a guide pin is fixedly connected to the lower end of the valve rod, a gland is bolt-connected to the upper end of the shell, a through hole is formed in the center of the gland, the valve rod passes through the through hole, and a sealing packing is arranged on the valve rod; the sealing packing can improve the sealing performance of the ball valve, and prevents leakage and other conditions; the adjusting ring is arranged to avoid the tolerance caused by thermal expansion and cold shrinkage.

Description

Technical Field

[0001] This invention relates to the field of valve technology, specifically to a pre-tightening sealing ball valve device. Background Technology

[0002] Valves are widely used for fluid flow regulation and control. Among them, ball valves are widely used in industrial production, transportation, water conservancy, municipal engineering, and other fields due to their simple structure and low failure rate. However, common ball valves on the market suffer from problems such as difficult maintenance, poor corrosion resistance, and easy wear.

[0003] To address the aforementioned issues, the 725 Research Institute of China Shipbuilding Industry Corporation designed a high-temperature graphite-sealed titanium alloy ball valve, patent number CN111022695A. This invention includes a valve body, a ball, a left valve seat assembly, a right valve seat assembly, a pin, a valve stem, a blow-proof ring, a graphite gasket, a PTFE gasket, graphite packing, a packing gland, a valve body sealing gasket, a limit block, and a handle or drive device.

[0004] This invention uses a graphite valve seat sealing method that combines a floating ball and a pre-tightening valve seat structure. It not only has corrosion resistance and good sealing performance, but also has a long service life. However, the invention is prone to damage and difficult to disassemble and replace when damaged.

[0005] To address the aforementioned issues, Shanghai Aerospace Science and Technology Group Co., Ltd. has designed a ball valve with a protective device, patent number CN112747135B. This invention comprises a ball valve body, a ball core rotatably mounted within the ball valve body, a valve stem with one end fixedly connected to the ball core and the other end extending out of the ball valve body, a handwheel detachably mounted on the valve stem, a locking device installed between the handwheel and the valve stem to prevent misoperation, and a protective device for protecting the ball valve body. The protective device includes a base, a guide rod mounted on the base, a sliding seat slidably mounted on the guide rod, a mounting seat fixedly mounted on the sliding seat, and a clamping device mounted on the mounting seat that automatically clamps the ball valve body for protection after the sliding seat slides to a predetermined position.

[0006] The invention described above can avoid damage caused by misoperation and has high safety and reliability. However, it still has the following problems: it is not suitable for high-temperature environments and disassembly and maintenance are cumbersome.

[0007] To address the aforementioned issues, Kaifeng Ruike Valve Co., Ltd. has invented a cryogenic ball valve with a pre-tightened sliding valve seat structure. The valve includes a valve body, a long-necked valve cover, a sliding valve seat, a handle, a ball, and a valve stem. A floating clamping mechanism is mounted on the valve body above the sliding valve seat. This mechanism includes a horizontally placed support plate and a guide plate installed below the support plate. Both the support plate and the guide plate have through holes for the valve stem to pass through. The guide plate has a guide hole on each of its left and right sides, with two guide holes on the same side. A sleeve is slidably installed in each guide hole, and an adjusting screw is threaded into the sleeve. A compression spring is fixedly connected between the lower surface of the support plate and the upper end of the sleeve. The lower end of the adjusting screw extends out of the sleeve and connects to the top of the sliding valve seat.

[0008] Although the above invention can solve the problem of fit between workpieces caused by thermal expansion and contraction due to temperature differences, its structure is complex and disassembly, installation and maintenance are troublesome.

[0009] In view of this, in order to overcome the above-mentioned technical problems, the present invention designs a pre-tightening sealing ball valve device, which solves the above-mentioned technical problems. Summary of the Invention

[0010] The technical objective of this invention is to provide a pre-tightening sealing ball valve device that is simple in structure, easy to disassemble and install, and avoids tolerance issues caused by thermal expansion and contraction.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] The present invention provides a pre-tightening sealing ball valve device comprising a housing, a control system, a valve ball, a sealing ring, and a valve stem;

[0013] The sealing ring is circular, and a circular adjusting ring is coaxially provided at one end of the sealing ring. Two quarter-circle openings are symmetrically opened on the adjusting ring. A spring is provided at the bottom of the adjusting ring. Two sealing grooves are provided inside the housing. The sealing grooves correspond exactly to the shapes of the sealing ring and the adjusting ring.

[0014] Two sealing rings are each fixedly installed in a sealing groove. The valve ball is rotatably installed between the two sealing rings, which clamp the valve ball in the middle. The valve ball can control the flow of fluid inside the ball valve by its own rotation. The end of the adjusting ring closest to the valve ball contacts the sealing groove, and the end of the sealing ring furthest from the valve ball is fixedly connected to the sealing groove by a spring. The valve stem is connected to the valve ball and is used to control the rotation of the valve ball to control the flow of fluid inside the housing. The operator controls the flow rate of fluid inside the ball valve by operating the valve stem. The adjusting ring can adjust and balance the tolerance caused by thermal expansion and contraction, and the spring can apply a certain pressure to the seal to make it fit tightly against the valve ball.

[0015] In practice, when fluid at 250°C flows through the ball valve, the sealing rings will expand due to heat. This shortens the distance between the two sealing rings, leading to an increase in the pressure exerted on the valve ball. This can cause difficulty in rotation or damage to the valve ball during rotation. Therefore, an adjusting ring is installed to balance the pressure exerted on the valve ball by the sealing rings based on temperature. Specifically, as the temperature rises, the adjusting ring expands under pressure. Because its coefficient of linear thermal expansion is greater than that of the sealing ring, the adjusting ring expands more significantly under the same temperature difference. This allows the adjusting ring to offset the distance change caused by the thermal expansion of the sealing rings, ultimately stabilizing the pressure exerted on the valve ball by the sealing rings.

[0016] A sealing gasket is provided between the sealing ring and the valve ball. The sealing gasket is fixedly connected to the sealing ring and slidably connected to the valve ball. An adjusting gasket is provided between the adjusting ring and the sealing groove. The adjusting gasket is fixedly connected to the adjusting ring. The sealing gasket is provided to reduce the friction between the sealing ring and the valve ball and to better fit them to reduce wear. The adjusting gasket, with a thickness and contact area with the sealing ring that are equal to the sealing gasket, is provided to balance the thickness of the sealing ring due to thermal expansion.

[0017] The valve ball has an installation hole, and the lower end of the valve stem is fixedly connected to a guide pin. The lower end of the valve stem is installed in the installation hole, and the installation is completed by inserting the valve stem downward into the installation hole. Compared with the traditional threaded installation, this installation method is more convenient. The guide pin is used to transmit the torque of the valve stem to the valve ball. This design can better realize the transmission of torque and avoid the loosening of threads during rotation in traditional threaded connections.

[0018] During installation, first install the valve ball into the inner housing, then insert the guide pin into the valve stem, and finally insert the valve stem and guide pin into the valve ball along the mounting hole, thus completing the installation and connection of the valve stem and valve ball.

[0019] A pressure cap is bolted to the upper end of the housing. A through hole is opened in the center of the pressure cap, through which the valve stem passes. A sealing packing is provided on the valve stem. The sealing packing can improve the internal sealing of the ball valve and prevent leakage. The valve stem contacts the inner wall of the through hole of the pressure cap through the sealing packing. The upper end of the sealing packing contacts the pressure cap. The cover plate presses the valve stem with the sealing packing to prevent the valve stem from falling off.

[0020] During installation, first pass the valve stem through the gland, then fill with sealing packing to limit and fix the valve stem. Next, insert the guide pin into the valve stem, and then install the valve stem and valve ball. After completing the entire installation process, finally fix the gland with bolts to complete the entire installation.

[0021] The sealing ring is detachable; the opening of the sealing groove perfectly matches the shape of the sealing ring.

[0022] During installation, first insert the sealing ring directly into the sealing groove, then rotate it 90°. After installing the sealing ring, press the valve ball between the two sealing rings. The two sealing rings secure the valve ball, and the valve ball also limits the position of the sealing rings. This installation method is simple and convenient.

[0023] The valve ball and the sealing gasket are provided with a ring structure that cooperates with each other with the valve stem as the axis. The circular pattern can guide the valve ball to rotate only with the valve stem as the axis, avoiding the valve ball from rotating in the opposite direction, which would obstruct the flow of fluid in the ball valve or cause abnormal backflow, thereby avoiding damage to the ball valve. In addition, it can also prevent the sealing ring from rotating and falling off during the operation of the ball valve, thereby improving the stability of the device.

[0024] A strain sensor is installed inside the valve stem to monitor the lateral bending of the valve stem. The strain sensor is electrically connected to the control system. The strain sensor enables monitoring of the internal structure of the ball valve. When the strain sensor detects stress on the valve stem and transmits the signal to the control system, the control system analyzes the data. If the stress exceeds a threshold, the control system will issue an alarm to alert the operator. At this point, the operator is aware of internal damage to the ball valve and can proceed with disassembly and repair.

[0025] The ball valve can be monitored from the outside without disassembling it, allowing for quick and effective fault detection and timely resolution before other components suffer indirect damage. Furthermore, the ball valve is easy to disassemble and install, making maintenance convenient and reducing the cost of later maintenance and repairs.

[0026] The sealing ring is made of martensitic stainless steel, which has a low coefficient of thermal expansion, making it suitable as a material for sealing rings. The adjusting pad is made of austenitic stainless steel, which has a high coefficient of thermal expansion, making it suitable as a material for adjusting rings. The sealing pad and adjusting pad are made of graphite, which has an extremely low coefficient of thermal expansion and, compared to metal materials, has good toughness, is softer, and has a low coefficient of friction, making it the ideal choice for sealing pads and adjusting pads.

[0027] Specifically, at approximately 250°C, the linear coefficient of thermal expansion of the martensitic stainless steel used for the sealing ring is approximately 1.2 × 10⁻⁶. -5 / ℃, the linear thermal expansion coefficient of the austenitic stainless steel used in the regulating ring is approximately 1.8 × 10⁻⁶. -5 / ℃, given that the sealing ring thickness is 6mm and the adjusting ring thickness is 4mm, the following calculations are performed:

[0028] The expansion thickness of the sealing ring per unit temperature: ΔL1=α1L1=1.2×10 -5 ×6=7.2×10 -5 mm;

[0029] The expansion thickness of the regulating coil per unit temperature: ΔL2=α2L2=1.8×10 -5 ×4=7.2×10 -5 mm;

[0030] The expansion thickness ΔL1 of the sealing ring per unit temperature is equal to the expansion thickness ΔL2 of the regulating ring per unit temperature. Therefore, when the high-temperature fluid flows inside the ball valve and causes the sealing ring and regulating ring to thermally expand, their expansion thicknesses are equal. Thus, the regulating ring precisely offsets the changes caused by the expansion of the sealing ring, keeping the distance between the two sealing rings stable. This ensures that the pressure applied by the sealing ring to the valve ball is constant, preventing valve ball wear caused by pressure changes.

[0031] The general installation process is as follows: First, insert the sealing ring directly into the sealing groove, then rotate it 90°. After installing the sealing ring, press the valve ball between the two sealing rings. The two sealing rings fix the valve ball, and the valve ball also limits the position of the sealing rings. After installing the valve ball, first pass the valve stem through the gland, then fill with sealing filler to limit and fix the valve stem. Next, insert the guide pin into the valve stem, and then insert the valve stem and guide pin into the valve ball along the mounting hole, thus completing the installation and connection of the valve stem and valve ball. After completing the entire installation process, finally fix the gland with bolts, thus completing the entire installation work.

[0032] When the strain sensor monitors the stress on the valve stem and transmits the signal to the control system, the control system analyzes the data. When the stress exceeds a threshold, the control system issues an alarm to alert the operator. At this point, the operator is aware that damage has occurred inside the ball valve, and disassembly and repair can be performed. Disassembly is simply a matter of reversing the installation process, making both disassembly and installation very convenient, as is maintenance, which reduces the cost of later maintenance and repair.

[0033] When the ball valve is in operation, a high-temperature fluid of 250°C flows inside. The sealing ring and the regulating ring undergo thermal expansion. Since the regulating ring has a greater coefficient of linear thermal expansion than the sealing ring, it expands more than the sealing ring when subjected to the same temperature difference. However, since the two have different thicknesses, calculations show that their expansion thicknesses are equal. Therefore, the regulating ring precisely offsets the changes caused by the expansion of the sealing ring, keeping the distance between the two sealing rings stable. This stabilizes the pressure applied to the valve ball by the sealing ring and prevents valve ball wear caused by pressure changes.

[0034] The beneficial effects of this invention are as follows:

[0035] 1. A pre-tightening sealing ball valve device of the present invention addresses the issue that when a fluid at 250°C flows through the ball valve, the sealing rings undergo thermal expansion, causing the distance between the two sealing rings to shorten. This leads to an increase in the pressure exerted on the valve ball by the two sealing rings, resulting in difficulty in rotation or damage to the valve ball during rotation. Therefore, an adjusting ring is provided to balance the pressure exerted on the valve ball by the sealing rings based on temperature. Specifically, as the temperature rises, the adjusting ring expands under pressure. Because its coefficient of linear thermal expansion is greater than that of the sealing ring, the adjusting ring expands more significantly under the same temperature difference. This allows the adjusting ring to offset the distance change caused by the thermal expansion of the sealing rings, ultimately stabilizing the pressure exerted on the valve ball by the sealing rings.

[0036] 2. A pre-tightening sealing ball valve device of the present invention comprises: first, inserting the sealing ring directly into the sealing groove; then rotating it 90° during installation; after installing the sealing ring, pressing the valve ball between the two sealing rings, which fix the valve ball in place and simultaneously limit the sealing rings; after installing the valve ball, first passing the valve stem through the gland, then filling it with sealing filler to limit and fix the valve stem; then inserting the guide pin into the valve stem; and finally inserting the valve stem and guide pin into the valve ball along the mounting hole, thereby completing the installation and connection of the valve stem and valve ball; after completing the entire installation process, finally securing the gland with bolts, thus completing the entire installation work.

[0037] When the strain sensor monitors the stress on the valve stem and transmits the signal to the control system, the control system analyzes the data. When the stress exceeds a threshold, the control system issues an alarm to alert the operator. At this point, the operator is aware that damage has occurred inside the ball valve, and disassembly and repair can be performed. Disassembly is simply a matter of reversing the installation process, making both disassembly and installation very convenient, as is maintenance, which reduces the cost of later maintenance and repair. Attached Figure Description

[0038] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the appearance of the present invention. Figure 1 ;

[0040] Figure 2 This is a schematic diagram of the appearance of the present invention. Figure 2 ;

[0041] Figure 3This is a front sectional view of the present invention;

[0042] Figure 4 This is a partial view of the present invention. Figure 1 ;

[0043] Figure 5 This is a partial view of the present invention. Figure 2 ;

[0044] Figure 6 This is a partial view of the present invention. Figure 3 ;

[0045] Figure 7 This is a schematic diagram of the valve stem structure of the present invention;

[0046] Figure 8 This is a schematic diagram of the connection between the valve stem and the valve ball of the present invention;

[0047] Figure 9 This is a side sectional view of the present invention;

[0048] Figure 10 This is a schematic diagram of the sealing ring structure of the present invention.

[0049] In the diagram: housing 1, sealing groove 11, valve ball 2, mounting hole 21, sealing ring 3, sealing gasket 31, adjusting ring 32, adjusting gasket 33, spring 34, valve stem 4, guide pin 41, sealing packing 42, gland 5. Detailed Implementation

[0050] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0051] like Figure 1 , Figure 2 and Figure 3 As shown, a pre-tightened sealing ball valve device includes a housing 1, a control system, a valve ball 2, a sealing ring 3, and a valve stem 4;

[0052] The sealing ring 3 is annular, and an annular adjusting ring 32 is coaxially provided at one end of the sealing ring 3. Two quarter-circle openings are symmetrically opened on the adjusting ring 32. A spring 34 is provided at the bottom of the adjusting ring 32. Two sealing grooves 11 are provided inside the housing 1. The sealing grooves 11 correspond exactly to the shapes of the sealing ring 3 and the adjusting ring 32.

[0053] Two sealing rings 3 are each fixedly installed in the sealing groove 11. The valve ball 2 is rotatably installed between the two sealing rings 3, with the two sealing rings 3 clamping the valve ball 2 in the middle. The valve ball 2 can control the flow of fluid in the ball valve by its own rotation. The end of the adjusting ring 32 near the valve ball 2 contacts the sealing groove 11, and the end of the sealing ring 3 away from the valve ball 2 is fixedly connected to the sealing groove 11 by a spring 34. The valve stem 4 is connected to the valve ball 2 and is used to control the rotation of the valve ball 2 to control the flow of fluid in the housing 1. The operator controls the flow rate of fluid in the ball valve by operating the valve stem 4. The adjusting ring 32 can adjust and balance the tolerance caused by thermal expansion and contraction, and the spring 34 can apply a certain pressure to the sealing ring 3 to make it tightly adhere to the valve ball 2.

[0054] The sealing ring 3 is provided with an adjusting ring 32 and a spring 34. The end of the sealing ring 3 near the valve ball 2 is in contact with the sealing groove 11, and the end of the sealing ring 3 away from the valve ball 2 is fixedly connected to the sealing groove 11 through the spring 34. The adjusting ring 32 can adjust and balance the tolerance caused by thermal expansion and contraction, and the spring 34 can apply a certain pressure to the sealing ring 3 to make it fit tightly against the valve ball 2.

[0055] In practice, when fluid at 250°C flows through the ball valve, the sealing rings 3 will expand due to heat. At this time, the distance between the two sealing rings 3 will shorten, which will increase the pressure exerted by the two sealing rings 3 on the valve ball 2. This will cause difficulty in rotation or damage to the valve ball 2 during rotation. Therefore, an adjusting ring 32 is provided to adjust and balance the pressure exerted by the sealing rings 3 on the valve ball 2 according to the temperature. Specifically, when the temperature rises, the adjusting ring 32 expands under force. Since its coefficient of linear thermal expansion is greater than that of the sealing ring 3, when it expands under the same temperature difference, the expansion range of the adjusting ring 32 is greater than that of the sealing ring 3. Thus, the adjusting ring 32 can offset the distance change caused by the thermal expansion of the sealing rings 3, and finally achieve the purpose of stabilizing the pressure of the sealing rings 3 on the valve ball 2.

[0056] like Figure 3 , Figure 4 , Figure 6 and Figure 10 As shown, a sealing gasket 31 is provided between the sealing ring 3 and the valve ball 2. The sealing gasket 31 is fixedly connected to the sealing ring 3 and slidably connected to the valve ball 2. An adjusting gasket 33 is provided between the adjusting ring 32 and the sealing groove 11. The adjusting gasket 33 is fixedly connected to the adjusting ring 32. The sealing gasket 31 is provided to reduce the friction between the sealing ring 3 and the valve ball 2 and to better fit them to reduce wear. The adjusting gasket 33, with a thickness and contact area with the sealing ring 3 that are equal to those of the sealing gasket 31, is provided to balance the thickness of the sealing ring 3 due to thermal expansion.

[0057] like Figure 3 , Figure 7and Figure 8 As shown, the valve ball 2 has a mounting hole 21, and the lower end of the valve stem 4 is fixedly connected to a guide pin 41. The lower end of the valve stem 4 is installed in the mounting hole 21. The installation is completed by inserting the valve stem 4 downward into the mounting hole 21. Compared with the traditional threaded installation, this installation method is more convenient. The guide pin 41 is used to transmit the torque of the valve stem 4 to the valve ball 2. This design can better realize the transmission of torque and avoid the loosening of threads during rotation in traditional threaded connections.

[0058] During installation, first install the valve ball 2 into the inner housing 1, then insert the guide pin 41 into the valve stem 4, and then insert the valve stem 4 and the guide pin 41 into the valve ball 2 along the mounting hole 21, thereby completing the installation and connection of the valve stem 4 and the valve ball 2.

[0059] like Figure 3 and Figure 5 As shown, a pressure cap 5 is bolted to the upper end of the housing 1. A through hole is opened in the center of the pressure cap 5, through which the valve stem 4 passes. A sealing packing 42 is provided on the valve stem 4. The sealing packing 42 can improve the sealing performance of the ball valve and prevent leakage. The valve stem 4 contacts the inner wall of the through hole of the pressure cap 5 through the sealing packing 42. The upper end of the sealing packing 42 contacts the pressure cap 5. The cover plate presses the valve stem 4 with the sealing packing 42 to prevent the valve stem 4 from falling off.

[0060] During the installation process, first pass the valve stem 4 through the gland 5, then fill the gland 42 with sealing filler to limit and fix the valve stem 4, then insert the guide pin 41 into the valve stem 4, and then install the valve stem 4 and the valve ball 2. After completing the entire installation process, finally fix the gland 5 with bolts to complete the entire installation.

[0061] like Figure 3 and Figure 9 As shown, the sealing ring 3 is detachable; the opening of the sealing groove 11 matches the shape of the sealing ring 3.

[0062] During installation, first insert the sealing ring 3 into the sealing groove 11, then rotate it 90°. After installing the sealing ring 3, press the valve ball 2 between the two sealing rings 3. The two sealing rings 3 fix the valve ball 2 in place, and the valve ball 2 also limits the position of the sealing rings 3. This installation method is simple and convenient.

[0063] like Figure 3As shown, the valve ball 2 and the sealing gasket 31 are provided with mutually cooperating annular structures with the valve stem 4 as the axis. The circular pattern can guide the valve ball 2 to rotate only with the valve stem 4 as the axis, avoiding the valve ball 2 from rotating in the opposite direction, which would cause the fluid flow inside the ball valve to be obstructed or abnormal backflow to occur, thereby avoiding damage to the ball valve; in addition, it can also prevent the sealing ring 3 from rotating and falling off when the ball valve is operating, thereby improving the stability of the device.

[0064] like Figure 3 As shown, a strain sensor is installed inside the valve stem 4. The strain sensor is used to monitor the left and right bending of the valve stem 4 and is electrically connected to the control system. The strain sensor enables monitoring of the inside of the ball valve. When the strain sensor detects the stress on the valve stem 4 and transmits the signal to the control system, the control system analyzes the data. When the stress exceeds a threshold, the control system issues an alarm to alert the operator. At this point, the operator is aware of internal damage to the ball valve and can proceed with disassembly and repair.

[0065] The ball valve can be monitored from the outside without disassembling it, allowing for quick and effective fault detection and timely resolution before other components suffer indirect damage. Furthermore, the ball valve is easy to disassemble and install, making maintenance convenient and reducing the cost of later maintenance and repairs.

[0066] like Figure 10 As shown, the sealing ring 3 is made of martensitic stainless steel, which has a small coefficient of thermal expansion, making it suitable as the material for the sealing ring 3; the adjusting pad 33 is made of austenitic stainless steel, which has a large coefficient of thermal expansion, making it suitable as the material for the adjusting ring 32; the sealing pad 31 and the adjusting pad 33 are made of graphite, which has an extremely small coefficient of thermal expansion and, compared to metal materials, has good toughness, is softer, and has a low coefficient of friction, making it the best choice for the sealing pad 31 and the adjusting pad 33.

[0067] Specifically, at approximately 250°C, the linear thermal expansion coefficient of the martensitic stainless steel used in the sealing ring 3 is approximately 1.2 × 10⁻⁶. -5 / ℃, the linear thermal expansion coefficient of the austenitic stainless steel used in the adjusting ring 32 is approximately 1.8×10. -5 / ℃, given that the thickness of sealing ring 3 is 6mm and the thickness of adjusting ring 32 is 4mm, the following calculations are performed:

[0068] The expansion thickness of sealing ring 3 per unit temperature: ΔL1=α1L1=1.2×10 -5 ×6=7.2×10 -5 mm;

[0069] The expansion thickness of the regulating coil 32 per unit temperature: ΔL2=α2L2=1.8×10 -5 ×4=7.2×10 -5 mm;

[0070] The expansion thickness ΔL1 of the sealing ring 3 per unit temperature is equal to the expansion thickness ΔL2 of the regulating ring 32 per unit temperature. Therefore, when the high-temperature fluid flows in the ball valve and causes the sealing ring 3 and the regulating ring 32 to expand thermally, their expansion thicknesses are equal. Thus, the regulating ring 32 exactly offsets the changes caused by the expansion of the sealing ring 3, keeping the distance between the two sealing rings 3 stable. This keeps the pressure applied to the valve ball 2 by the sealing ring 3 constant, avoiding wear of the valve ball 2 due to pressure changes.

[0071] like Figure 3 As shown, the overall installation process is as follows: First, insert the sealing ring 3 into the sealing groove 11, then rotate it 90°. After installing the sealing ring 3, press the valve ball 2 between the two sealing rings 3. The two sealing rings 3 fix the valve ball 2, and the valve ball 2 also limits the sealing rings 3. After installing the valve ball 2, first pass the valve stem 4 through the gland 5, then fill the gland with sealing filler 42 to limit and fix the valve stem 4. Then, insert the guide pin 41 into the valve stem 4, and then insert the valve stem 4 and the guide pin 41 into the valve ball 2 along the mounting hole 21, thus completing the installation and connection of the valve stem 4 and the valve ball 2. After completing the entire installation process, finally fix the gland 5 with bolts, thus completing the entire installation work.

[0072] When the strain sensor monitors the stress on valve stem 4 and transmits the signal to the control system, the control system analyzes the data. When the stress exceeds a threshold, the control system issues an alarm to alert the operator. At this point, the operator is aware that damage has occurred inside the ball valve, and disassembly and repair can be performed. Disassembly is simply a matter of reversing the installation process, making both disassembly and installation very convenient, and repairs are also easy, reducing the cost of later maintenance and repairs.

[0073] like Figure 3 As shown, when the ball valve is in operation, a high-temperature fluid of 250°C flows inside the ball valve. The sealing ring 3 and the adjusting ring 32 undergo thermal expansion. Since the linear thermal expansion coefficient of the adjusting ring 32 is greater than that of the sealing ring 3, the adjusting ring 32 expands to a greater extent than the sealing ring 3 when it expands under the same temperature difference. Since the two have different thicknesses, it can be calculated that their expansion thicknesses are equal. Therefore, the adjusting ring 32 exactly offsets the changes caused by the expansion of the sealing ring 3, so that the distance between the two sealing rings 3 remains stable. This stabilizes the pressure applied to the valve ball 2 by the sealing ring 3 and avoids wear of the valve ball 2 due to pressure changes.

[0074] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pre-tightening sealing ball valve device, comprising a housing (1), a control system, a valve ball (2), a sealing ring (3), and a valve stem (4), characterized in that: The sealing ring (3) is annular. One end of the sealing ring (3) is coaxially provided with an annular adjusting ring (32). The adjusting ring (32) has two quarter-circle openings symmetrically opened. The housing (1) is provided with two sealing grooves (11). The sealing grooves (11) correspond exactly to the shapes of the sealing ring (3) and the adjusting ring (32). The two sealing rings (3) are fixedly installed in the sealing grooves (11). The valve ball (2) is rotatably installed between the two sealing rings (3). The end of the adjusting ring (32) near the valve ball (2) is in contact with the sealing groove (11). The end of the sealing ring (3) away from the valve ball (2) is fixedly connected to the sealing groove (11) through a spring (34). The valve stem (4) is connected to the valve ball (2). The valve stem (4) is used to control the rotation of the valve ball (2) to control the flow of fluid in the housing (1). The adjusting ring (32) is an integrally formed annular component. A sealing gasket (31) is provided between the sealing ring (3) and the valve ball (2), the sealing gasket (31) is fixedly connected to the sealing ring (3), and the sealing gasket (31) is slidably connected to the valve ball (2). An adjusting gasket (33) is provided between the adjusting ring (32) and the sealing groove (11), and the adjusting gasket (33) is fixedly connected to the adjusting ring (32). The sealing ring (3) is made of martensitic stainless steel. The adjusting gasket (33) is made of austenitic stainless steel. When the high-temperature fluid flowing inside the ball valve causes the sealing ring (3) and the regulating ring (32) to expand thermally, their expansion thicknesses are equal. Therefore, the regulating ring (32) just offsets the changes caused by the expansion of the sealing ring (3), so that the distance between the two sealing rings (3) remains stable. This keeps the pressure applied to the valve ball (2) by the sealing ring (3) constant, avoiding wear of the valve ball (2) due to pressure changes.

2. The pre-tightening sealing ball valve device according to claim 1, characterized in that: The valve ball (2) has a mounting hole (21), and the lower end of the valve stem (4) is fixedly connected to a guide pin (41). The lower end of the valve stem (4) is installed in the mounting hole (21), and the guide pin (41) is used to transmit the torque of the valve stem (4) to the valve ball (2).

3. The pre-tightening sealing ball valve device according to claim 1, characterized in that: The upper end of the housing (1) is bolted to a pressure cap (5). The pressure cap (5) has a through hole in the center. The valve stem (4) passes through the through hole. A sealing packing (42) is provided on the valve stem (4). The valve stem (4) contacts the inner wall of the through hole of the pressure cap (5) through the sealing packing (42). The upper end of the sealing packing (42) contacts the pressure cap (5).

4. The pre-tightening sealing ball valve device according to claim 1, characterized in that: The sealing ring (3) is detachable.

5. The pre-tightening sealing ball valve device according to claim 1, characterized in that: The valve ball (2) and the sealing gasket (31) are provided with annular structures that cooperate with each other with the valve stem as the axis.

6. A pre-tightening sealing ball valve device according to claim 2, characterized in that: A strain sensor is installed inside the valve stem (4). The strain sensor is used to monitor the left and right bending of the valve stem (4). The strain sensor is electrically connected to the control system.

7. A pre-tightening sealing ball valve device according to claim 1, characterized in that: The sealing gasket (31) and adjusting gasket (33) are made of graphite.

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