Stop valve for ship

Abstract

The invention relates to the field of stop valves, in particular to a marine stop valve which comprises a valve body, the valve body is provided with an inlet and an outlet which are used for conveying working media and connected with an external pipeline through metric threads, a sealing gasket is arranged between the valve body and a valve cover, and the upper end of the valve body is connected with the lower end of the valve cover through threads. The valve body and the valve cover are in sealing fit through the sealing gasket, and the gland is pressed and fixed through a threaded connection structure of the valve body and the valve cover. The first semi-ring and the second semi-ring are arranged in the opening sliding groove, connected with the valve disc, of the ejector rod, the sealing faces of the first semi-ring and the second semi-ring are precisely attached, the problems that a traditional stop valve is poor in lower sealing centering performance and low in sealing face attaching degree are solved from the structural level, the lower sealing performance is greatly improved, and medium leakage is effectively avoided; and the safety of ship pipeline medium transmission is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of gate valves, and more specifically to a marine gate valve. Background Technology

[0002] Marine gate valves are key valves used to control the flow of media in marine piping systems. They are typically made of corrosion-resistant and high-pressure-resistant materials such as bronze, cast steel, or cast iron, and feature internal thread or flange connections. They are suitable for various media, including seawater, fresh water, oil, and steam, and operate stably within a temperature range of -196℃ to 650℃. They possess excellent sealing performance and shock resistance, and are widely used in marine power, fuel oil, lubricating oil, and fire protection systems. Manufactured according to different standards such as CB / T 309-2008 and GB / T584, they come in various structural types, including straight-through and right-angle types. As an important component ensuring the safe operation of ships, they are widely used in various fluid transmission pipelines on ships and are an indispensable key component of marine equipment.

[0003] Currently, existing marine gate valves still suffer from numerous technical defects in practical applications due to limitations in structural design and material selection, making them difficult to adapt to the special operating conditions required for ship navigation. For example, the lower sealing structure lacks a centering adjustment design, the relative position of the valve stem and valve seat is fixed, and the sealing surfaces of the valve disc and valve seat cannot achieve precise contact, resulting in poor sealing performance and easy media leakage, which seriously affects the safety of pipeline operation. Furthermore, the upper seal often adopts a traditional packing seal structure, and the tightness of the packing is difficult to control precisely. Loose packing can easily cause media leakage, while tight packing can cause valve stem jamming, making valve opening and closing difficult. Moreover, the packing is susceptible to media corrosion and mechanical wear, resulting in rapid deterioration of sealing performance and requiring frequent maintenance and replacement. Summary of the Invention

[0004] This invention addresses the technical problems existing in the prior art by providing a marine shut-off valve.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A marine gate valve includes a valve body, the valve body is provided with an inlet and an outlet for the transmission of working medium, and the valve body is connected to an external pipeline through a metric thread. A sealing gasket is provided between the valve body and the valve cover. The upper end of the valve body is connected to the lower end of the valve cover through a thread. The valve body and the valve cover achieve a sealing fit through the sealing gasket. The threaded connection structure of the valve body and the valve cover completes the pressing and fixing of the gland. A valve stem is provided through the valve cover and the pressure cap. The upper end of the valve stem extends to the outer side of the upper end of the valve cover, and the lower end of the valve stem extends to the internal cavity of the valve body. The valve stem is threaded to the upper end of the valve cover. An open slide groove is provided at the lower end of the valve stem, and the valve stem is connected to the top rod through the open slide groove. A stroke indicator is installed at the upper end of the valve stem to indicate the opening and closing position of the valve. A handwheel is also installed at the upper end of the valve stem, and the handwheel is fixedly connected to the valve stem by a nut. The valve body and valve cover are connected by a threaded connection. The sealing gasket between them is compressed by the preload of the threaded connection. Utilizing the compression sealing principle of solid contact, the sealing gasket fills the microscopic gap between the valve body and valve cover mating surfaces, achieving a static seal. The compression force of this threaded connection is simultaneously transmitted to the gland, and the gland is fixed through mechanical force transmission, making the fit between the gland and valve body more stable and forming an integrated upper sealing structure. The valve stem runs through the valve cover and gland, following the principle of linear force transmission. Its upper end is threaded to the valve cover, providing the transmission basis for the rotation and lifting of the valve stem. The lower end's open slide groove and connection with the top rod realize the smooth transmission of rotational motion to linear lifting motion. The stroke indicator and handwheel are assembled at the upper end of the valve stem. The handwheel is fixed by a nut to ensure the effective transmission of operating torque. The linkage between the stroke indicator and the valve stem relies on the synchronicity of mechanical movement, converting the displacement of the valve stem into a direct indication of the valve's open / closed position, realizing the coordination of operation and status feedback, allowing the operator to accurately judge the valve's operating condition.

[0006] In a preferred embodiment, a push rod is fitted into the open groove at the lower end of the valve stem. The lower end of the push rod extends to the valve seat inside the valve body. The lower end of the push rod has an open groove, and the push rod is connected to the valve disc through the open groove. A first half-ring and a second half-ring are fitted into the open groove connecting the push rod and the valve disc. Through the cooperation of the first half-ring and the second half-ring, the alignment between the valve disc and the valve seat can be adjusted when the valve stem moves the valve disc up and down.

[0007] In a preferred embodiment, a valve seat is fixedly installed inside the lower part of the valve body, and the valve seat is threadedly connected to the lower part of the valve body. An anti-loosening cover is installed on the upper outer side of the valve cover, and a locking ring is provided between the anti-loosening cover and the valve cover. The anti-loosening cover is connected and fixed to the valve cover through the locking ring.

[0008] In a preferred embodiment, two annular grooves are provided on the outer circumference of the top rod, and a second O-ring is installed in each of the two annular grooves. The two second O-rings form a double sealing structure to achieve the upper sealing of the marine shut-off valve.

[0009] In a preferred embodiment, an annular groove is formed on the outer circumference of the valve seat, and a second O-ring is installed in the annular groove. The second O-ring is used to seal the threaded connection mating surface between the valve body and the valve seat to ensure the sealing performance of the threaded connection.

[0010] In a preferred embodiment, the push rod, pressure cap, first half-ring, valve body, valve stem, valve cover, anti-loosening cap, stroke indicator, and second half-ring are all made of bronze. The valve disc and valve seat are both made of titanium alloy, which improves the corrosion resistance of the gate valve and extends its service life.

[0011] In a preferred embodiment, the sealing gasket is made of polytetrafluoroethylene.

[0012] In a preferred embodiment, both the first O-ring and the second O-ring are made of nitrile rubber.

[0013] The beneficial effects of this invention are as follows: by setting the first half-ring and the second half-ring in the open sliding groove connecting the top rod and the valve disc, the centering of the valve disc and the valve seat is autonomously adjusted. When the valve rod drives the valve disc to move up and down, the valve disc can adjust its posture according to the position of the valve seat sealing surface in the radial movement space, so that the sealing surfaces of the two are precisely fitted. This solves the problems of poor centering of the bottom seal and low sealing surface fit of traditional gate valves from a structural perspective, greatly improves the bottom sealing performance, effectively avoids media leakage, and ensures the safety of media transmission in ship pipelines. The valve adopts a double sealing structure with double O-rings on the outside of the top rod to replace the traditional packing seal. The elastic seal relies on its own deformation to achieve sealing, without the need to apply additional clamping force. Furthermore, the valve seat and valve body are designed as a threaded, detachable structure, and the valve disc is also an independently assembled component. When the sealing surface is damaged, the valve seat or valve disc can be disassembled and replaced separately without replacing the entire valve body, valve stem, and other core components. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the present invention.

[0015] In the diagram: 1. Handwheel; 2. Locking ring; 3. Push rod; 4. Pressure cap; 5. Sealing gasket; 6. First half ring; 7. Valve body; 8. Valve disc; 9. Valve stem; 10. Valve cover; 11. Anti-loosening cover; 12. Stroke indicator; 13. Second half ring; 14. First O-ring; 15. Valve seat; 16. Second O-ring. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] As attached Figure 1 As shown, this embodiment provides: a marine gate valve, including a valve body 7, an inlet and an outlet for transmitting working medium, and the valve body 7 is connected to an external pipeline through a metric thread. A sealing gasket 5 is provided between the valve body 7 and the valve cover 10. The upper end of the valve body 7 is connected to the lower end of the valve cover 10 through a thread. The valve body 7 and the valve cover 10 achieve a sealing fit through the sealing gasket 5. The threaded connection structure of the valve body 7 and the valve cover 10 completes the pressing and fixing of the pressure cover 4. A valve stem 9 is provided through the valve cover 10 and the pressure cap 4. The upper end of the valve stem 9 extends to the outer side of the upper end of the valve cover 10, and the lower end of the valve stem 9 extends to the internal cavity of the valve body 7. The upper end of the valve stem 9 is threadedly connected to the upper end of the valve cover 10. An open slide groove is provided at the lower end of the valve stem 9. The valve stem 9 is connected to the top rod 3 through the open slide groove. A stroke indicator 12 is installed at the upper end of the valve stem 9. The stroke indicator 12 is used to indicate the opening and closing position of the valve. A handwheel 1 is also installed at the upper end of the valve stem 9. The handwheel 1 is fixedly connected to the valve stem 9 by a nut.

[0018] Specifically, this application uses the valve body 7 as the core load-bearing component. The inlet and outlet are connected to the external pipeline through metric threads. Relying on the standardized pitch and meshing characteristics of the metric threads, it achieves precise adaptation with the general marine pipeline. At the same time, the threaded connection provides a basic seal for media transmission and makes the installation and disassembly of the valve more in line with the construction specifications of marine pipelines.

[0019] Furthermore, the valve body 7 and the valve cover 10 are connected by a threaded connection. The sealing gasket 5 between them is pressed by the pre-tightening force of the threaded connection. Utilizing the solid contact compression sealing principle, the sealing gasket 5 fills the microscopic gap between the mating surfaces of the valve body 7 and the valve cover 10 to achieve static sealing. At the same time, the compression force of the threaded connection is transmitted to the gland 4, and the gland 4 is fixed through the transmission of mechanical force, making the fit between the gland 4 and the valve body 7 more stable and forming an integrated upper sealing structure.

[0020] The valve stem 9 runs through the valve cover 10 and the gland 4, following the principle of linear force transmission. Its upper end is threaded to the valve cover 10, providing a transmission basis for the rotation and lifting of the valve stem 9. The lower end open slide groove connects to the push rod 3, realizing the smooth transmission of rotational motion to linear lifting motion. The stroke indicator 12 and the handwheel 1 are assembled on the upper end of the valve stem 9. The handwheel 1 is fixed by a nut to ensure the effective transmission of operating torque. The linkage between the stroke indicator 12 and the valve stem 9 relies on the synchronicity of mechanical motion to convert the displacement of the valve stem 9 into a direct indication of the valve opening and closing position, realizing the coordination of operation action and status feedback, allowing the operator to accurately judge the valve condition.

[0021] A push rod 3 is installed in the open slide groove at the lower end of the valve stem 9. The lower end of the push rod 3 extends to the valve seat 15 inside the valve body 7. The lower end of the push rod 3 has an open slide groove. The push rod 3 is connected to the valve disc 8 through the open slide groove. A first half ring 6 and a second half ring 13 are installed in the open slide groove connecting the push rod 3 and the valve disc 8. Through the cooperation of the first half ring 6 and the second half ring 13, the alignment of the valve disc 8 and the valve seat 15 can be adjusted when the valve stem 9 drives the valve disc 8 to move up and down.

[0022] Specifically, the push rod 3, serving as an intermediate component for power transmission between the valve stem 9 and the valve disc 8, is assembled within the open groove at the lower end of the valve stem 9. Utilizing the adaptability of the groove's structure to the push rod 3, seamless power transmission is achieved. The push rod 3 extends above the valve seat 15 inside the valve body 7, following the spatial design principle of media flow control. This allows the push rod 3 to precisely act on the sealing surface of the valve seat 15 as it drives the valve disc 8's lifting and lowering motion, directly controlling the flow of the media. The open groove at the lower end of the push rod 3 connects to the valve disc 8. The first half-ring 6 and the second half-ring 13 assembled within the groove are separate structures. Their engagement principle relies on the splicing characteristics of the annular separate structure, both limiting the valve disc 8 in the axial direction to prevent it from detaching from the groove during lifting and lowering, and reserving a clearance in the radial direction to avoid rigidly constraining the radial fine-tuning of the valve disc 8, thus ensuring the flexibility of the valve disc 8's movement. The cooperation between the first half-ring 6 and the second half-ring 13 provides the core structural support for the centering adjustment of the valve disc 8 and the valve seat 15. When the valve stem 9 drives the valve disc 8 to move up and down, the valve disc 8 can autonomously adjust its radial posture according to the actual position of the sealing surface of the valve seat 15 within the radial movement space formed by the slide groove, the first half-ring 6, and the second half-ring 13. Relying on the self-adaptive principle of the mechanical structure, the sealing surface of the valve disc 8 and the sealing surface of the valve seat 15 can achieve precise fit. This solves the problem of poor centering caused by the fixed relative position of the valve stem and the valve seat in traditional gate valves from a structural perspective, and improves the fit of the lower seal.

[0023] A valve seat 15 is fixedly installed inside the lower part of the valve body 7. The valve seat 15 is threadedly connected to the lower part of the valve body 7. A groove is opened on the outer circumferential surface of the valve seat 15. An anti-loosening cover 11 is installed on the upper outer side of the valve cover 10. A locking ring 2 is provided between the anti-loosening cover 11 and the valve cover 10. The anti-loosening cover 11 is connected and fixed to the valve cover 10 through the locking ring 2.

[0024] Specifically, the valve seat 15 and the lower part of the valve body 7 are connected by threads. Utilizing the engagement and positioning characteristics of the threads, the valve seat 15 is precisely fixed inside the valve body 7. Simultaneously, the detachable nature of the threaded connection allows the valve seat 15 to be disassembled and replaced individually, adhering to the design principle of independent assembly of vulnerable parts. This avoids the problem of needing to replace the entire valve body when the traditional sealing surface is damaged. A single groove on the outer circumferential surface of the valve seat 15 provides precise installation limits for the first O-ring 14. The depth and width of the groove are matched to the size of the first O-ring 14, preventing displacement of the first O-ring 14 during valve operation. After the first O-ring 14 is installed in the groove, it fills the gap between the threaded connection surfaces of the valve body 7 and the valve seat 15 using the deformation principle of an elastic body, eliminating sealing dead angles in the threaded fit, achieving static sealing compensation at the threaded connection, and preventing media leakage from the thread gaps. The anti-loosening cover 11 is assembled on the upper outer side of the valve cover 10. The locking ring 2 between it and the valve cover 10 relies on the mechanical principle of clamping and fixing. The radial clamping force of the locking ring 2 tightly connects the anti-loosening cover 11 and the valve cover 10. This structure fully considers the vibration conditions during the ship's navigation process. It uses the anti-loosening characteristics of the locking ring 2 to counteract the mechanical loosening force caused by vibration, and prevents the anti-loosening cover 11 and the upper parts from being displaced due to vibration. At the same time, the anti-loosening cover 11 protects the valve stem 9, stroke indicator 12 and other parts on the upper part of the valve cover 10, reduces the corrosion of internal parts by external salt spray and water vapor, and improves the stability of the overall structure.

[0025] Two annular grooves are provided on the outer circumference of the top rod 3. A second O-ring 16 is installed in each of the two annular grooves, and a double sealing structure is formed by the two second O-rings 16 to achieve the upper sealing of the marine gate valve.

[0026] Specifically, the two annular grooves on the outer circumference of the push rod 3 follow the design principle of multi-point sealing. The two grooves are equidistant along the axial direction of the push rod 3, forming two independent sealing points. The annular structure of the grooves fits the cylindrical surface of the push rod 3, providing full circumferential installation limit for the second O-ring 16, ensuring the fit between the second O-ring 16 and the push rod 3, and preventing uneven wear or displacement of the seal during the lifting and lowering of the push rod 3. The two second O-rings 16 are assembled in the grooves to form a double sealing structure. Relying on the superposition principle of elastic sealing, the nitrile rubber second O-ring 16 undergoes elastic deformation under the compression of the push rod 3 and the valve body 7, and fits tightly against the metal surface. The first second O-ring 16 can achieve the main barrier against the medium, while the second second O-ring 16 forms a secondary sealing barrier. Even if the first seal leaks a little, the second seal can effectively block it, greatly improving the reliability of the upper seal. This double O-ring sealing structure replaces the traditional packing seal. Following the adaptation principle of dynamic sealing, the elastic seal achieves sealing by its own deformation without the need for additional clamping force. This fundamentally solves the technical defects of traditional packing seals, such as "leakage when compressed and jamming when compressed". At the same time, the flexible fit between the second O-ring 16 and the push rod 3 will not affect the lifting and lowering movement of the push rod 3, making the valve opening and closing operation smoother and adapting to the dynamic working condition of continuous lifting and lowering of the valve stem 9.

[0027] An annular groove is provided on the outer circumference of the valve seat 15, and a second O-ring 16 is installed in the annular groove. The second O-ring 16 is used to seal the threaded connection mating surface between the valve body 7 and the valve seat 15 to ensure the sealing performance of the threaded connection.

[0028] Specifically, a single annular groove is formed on the outer circumference of the valve seat 15. Its position precisely matches the threaded connection mating surface of the valve body 7 and the valve seat 15, following the design principle of overlapping the sealing surface and the mating surface. The depth and width of the groove are designed according to the elastic deformation requirements of the second O-ring 16, ensuring that the second O-ring 16 can be effectively limited while allowing it to deform sufficiently under compression to achieve a tight fit with the threaded connection surface. The second O-ring 16, assembled within the groove, utilizes the gap-filling principle of the elastomer. Under the pre-tightening force of the threaded engagement between the valve body 7 and the valve seat 15, the nitrile rubber second O-ring 16 undergoes elastic deformation, filling the microscopic gaps in the threaded connection mating surface. Since the threaded connection mating surface has natural thread clearances, the deformation of the second O-ring 16 eliminates these sealing dead angles, forming a continuous sealing surface and achieving effective sealing of the threaded connection surface. This sealing structure is designed for high-pressure operation of marine gate valves. Following the pressure adaptation principle of static sealing, the working pressure of 10MPa will generate a medium thrust on the threaded connection surface, and the elastic fit of the second O-ring 16 will become tighter as the pressure increases, forming a pressure self-sealing effect. This effectively prevents high-pressure medium from leaking from the threaded connection surface between the valve body 7 and the valve seat 15, and is suitable for the sealing requirements of various working media such as seawater and fuel oil.

[0029] The top rod 3, pressure cap 4, first half ring 6, valve body 7, valve stem 9, valve cover 10, anti-loosening cover 11, stroke indicator 12, and second half ring 13 are all made of bronze. Both the valve disc 8 and the valve seat 15 are made of titanium alloy. This material enhances the corrosion resistance of the gate valve and extends its service life.

[0030] Specifically, the top rod 3, gland 4, first half-ring 6, valve body 7, valve stem 9, valve cover 10, anti-loosening cover 11, stroke indicator 12, and second half-ring 13 are made of bronze. Following the principle of matching material characteristics with the usage environment, bronze has excellent corrosion resistance in marine environments. Its copper alloy composition can form a dense oxide film in the humid and salt spray marine environment, resisting electrochemical corrosion and media erosion. At the same time, bronze has excellent casting and machining performance, which can meet the forming requirements of the complex structure of the valve body and ensure the processing accuracy and connection fit of the components. The valve disc 8 and valve seat 15, as key sealing components, are made of titanium alloy. Relying on the material properties of titanium alloy, it not only has better corrosion resistance than bronze, but also has high strength, high hardness and lightweight characteristics. The sealing surfaces of the valve disc 8 and valve seat 15 will generate friction and erosion during the valve opening and closing process. The high strength of titanium alloy can improve the wear resistance and erosion resistance of the sealing surface and extend the service life of the sealing surface. The lightweight characteristics can reduce the lifting inertia of the valve disc 8, making the valve opening and closing operation easier.

[0031] The sealing gasket 5 is made of polytetrafluoroethylene.

[0032] Both the first O-ring 14 and the second O-ring 16 are made of nitrile rubber.

Claims

1. A marine gate valve, characterized in that, Includes a valve body (7), which is provided with an inlet and an outlet for the transmission of working medium. The valve body (7) is connected to an external pipeline through a metric thread. A sealing gasket (5) is provided between the valve body (7) and the valve cover (10). The upper end of the valve body (7) is connected to the lower end of the valve cover (10) through a thread. The valve body (7) and the valve cover (10) achieve a sealing fit through the sealing gasket (5). The threaded connection structure of the valve body (7) and the valve cover (10) completes the pressing and fixing of the pressure cover (4). A valve stem (9) is provided through the valve cover (10) and the pressure cap (4). The upper end of the valve stem (9) extends to the outer side of the upper end of the valve cover (10), and the lower end of the valve stem (9) extends to the internal cavity of the valve body (7). The upper end of the valve stem (9) is threaded to the upper end of the valve cover (10). An open slide groove is provided at the lower end of the valve stem (9). The valve stem (9) is connected to the top rod (3) through the open slide groove. A stroke indicator (12) is installed at the upper end of the valve stem (9). The stroke indicator (12) is used to indicate the opening and closing position of the valve. A handwheel (1) is also installed at the upper end of the valve stem (9). The handwheel (1) is fixedly connected to the valve stem (9) by a nut.

2. A marine shut-off valve according to claim 1, characterized in that, A push rod (3) is installed in the open groove at the lower end of the valve stem (9). The lower end of the push rod (3) extends to the valve seat (15) inside the valve body (7). The lower end of the push rod (3) has an open groove. The push rod (3) is connected to the valve disc (8) through the open groove. A first half ring (6) and a second half ring (13) are installed in the open groove connecting the push rod (3) and the valve disc (8). Through the cooperation of the first half ring (6) and the second half ring (13), the alignment between the valve disc (8) and the valve seat (15) can be adjusted when the valve stem (9) drives the valve disc (8) to move up and down.

3. A marine shut-off valve according to claim 2, characterized in that, A valve seat (15) is fixedly installed inside the lower part of the valve body (7). The valve seat (15) is threadedly connected to the lower part of the valve body (7). An anti-loosening cover (11) is installed on the upper outer side of the valve cover (10). A locking ring (2) is provided between the anti-loosening cover (11) and the valve cover (10). The anti-loosening cover (11) is connected and fixed to the valve cover (10) through the locking ring (2).

4. A marine shut-off valve according to claim 2, characterized in that, Two annular grooves are provided on the outer circumference of the top rod (3), and a first O-ring (14) is installed in each of the two annular grooves. The two first O-rings (14) form a double sealing structure to achieve the upper sealing of the marine stop valve.

5. A marine shut-off valve according to claim 3, characterized in that, An annular groove is provided on the outer circumference of the valve seat (15), and a second O-ring (16) is installed in the annular groove. The second O-ring (16) is used to seal the threaded connection mating surface between the valve body (7) and the valve seat (15).

6. A marine shut-off valve according to claim 2, characterized in that, The top rod (3), pressure cap (4), first half ring (6), valve body (7), valve stem (9), valve cover (10), anti-loosening cover (11), stroke indicator (12), and second half ring (13) are all made of bronze. The valve disc (8) and valve seat (15) are both made of titanium alloy.

7. A marine gate valve according to claim 1, characterized in that, The sealing gasket (5) is made of polytetrafluoroethylene.

8. A marine shut-off valve according to claim 4, characterized in that, Both the first O-ring (14) and the second O-ring (16) are made of nitrile rubber.

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