Easy to open and close, high reliability, balanced, controllable, high pressure stop check valve

Abstract

The present invention relates to a high-reliability balanced controllable high-pressure stop check valve that is easy to open and close. The valve sleeve is installed in the inner cavity of the valve body, the valve stem is connected to the valve sleeve in a sliding fit, the lower end of the valve stem is connected to a valve core, and the lower end of the valve stem can move up and down in the inner cavity of the valve core to form a valve core valve stem assembly structure; a spring seat and a spring are installed in the hole at the lower end of the valve stem, and the end of the spring seat is always in contact with the valve core under the action of the spring; the circular edge line at the lower end of the valve core and the inclined surface below the inner cavity of the valve sleeve together form a sealing pair; the valve cover is fixedly connected to the upper end of the valve body through a thread, and the valve sleeve is axially positioned and fixed by a positioning sleeve; an indicator is installed on the top of the valve cover, a transmission rod is threadedly connected to the valve cover, the upper end of the transmission rod is fixedly connected to a hand wheel, and the lower end is connected to the upper end boss of the valve stem through a radial groove on the transmission rod. The present invention adopts a fully balanced structure, which reduces the manual opening and closing operating torque of the stop check valve; and adopts a valve sleeve structure to improve the maintainability of the stop check valve.

Description

Technical Field

[0001] The present invention relates to a stop check valve suitable for use in a ship's compressed air system to isolate seawater from air, and in particular to a balanced stop check valve that is manually controllable in opening and closing and suitable for high-pressure applications. Background Art

[0002] The stop-check valve in a ship's compressed air system isolates the system piping from the overboard seawater. When the system is performing an exhaust task, compressed air pushes the stop-check valve spool, allowing the system to exhaust air overboard. Once the task is complete, the stop-check valve must ensure a reliable non-return seal to prevent overboard seawater from backflowing into the system, accelerating corrosion of piping and equipment, and posing a significant safety hazard. This ensures vessel safety to a certain extent. In an emergency, the user should be able to forcefully open or close the stop-check valve with a relatively easy-to-operate torque.

[0003] The stop check valves currently used in ship compressed air systems have disadvantages such as large manual opening torque, unreliable check, difficulty in processing and maintenance, and no position holding function or forced opening function. In addition, the installation location has poor accessibility, which brings great inconvenience to the use of the valve.

[0004] The working pressure of the compressed air system can be as high as several hundred kilograms. There are two types of valve core structures of traditional check valves: one is a positive-acting structure. To ensure effective sealing, the direction of the force exerted by the working medium on the valve core is consistent with the direction of valve closing. This type of structure has a large manual opening torque or may even be impossible to open manually; the other is a reaction-acting structure. The medium force on the valve core is consistent with the direction of valve opening. Manual opening is more convenient, but the force required for forced closing must overcome the medium force and meet the sealing pressure ratio requirements. This greatly increases the difficulty of closing and has low reliability.

[0005] When the stop check valve in a ship's compressed air system functions as a check valve, one end of the valve core is acted upon by the seawater pressure outside the ship, while the other end is acted upon by the compressed air remaining in the air line. The two forces act in opposite directions and cancel each other out, reducing the check sealing force. This is especially true under low-pressure check conditions, where reliable check is not possible due to the relatively small check force of the medium. Some check valves take into account the influence of the valve core's gravity and the requirements for installation direction, which are not conducive to actual installation and layout.

[0006] Existing stop check valves fail to simultaneously achieve the advantages of controllable opening and closing, low operating torque, reliable non-return function, and easy processing and maintenance. For example, the stop check valve disclosed in Chinese Patent CN206918339U has a valve disc with a curved end surface that forms a seal with the boss surface on the valve body. The medium's active area on the disc is not completely equal to that of the bushing, resulting in incomplete medium force balance. Consequently, the operating torque remains very high when used in high-pressure applications. The valve disc utilizes a hard seal structure, using the boss surface of the valve body as the sealing surface. Damage to the sealing surface requires complete disassembly of the valve body and disc for repair, significantly increasing the difficulty of processing and maintenance. There is no point of engagement between the upper end of the disc and the valve stem, making forced opening impossible. Chinese Patent CN106051171A discloses a pressure-self-balancing stop check valve that structurally balances the inlet medium force, but lacks a spring check mechanism. Consequently, non-return performance cannot be guaranteed under low-pressure conditions, installation orientation affects non-return performance, and the valve does not have a forced opening and closing function. Therefore, the existing stop check valve cannot meet the use requirements of ship compressed air systems, especially high-pressure air systems. Summary of the Invention

[0007] In response to the technical defects of the stop check valves currently used in ship compressed air systems, the present invention aims to provide a high-reliability, balanced, controllable high-pressure stop check valve that is easy to open and close, has controllable opening and closing, reliable performance, and is suitable for high-pressure occasions.

[0008] To achieve the above-mentioned purpose, the technical solution of the present invention is: an easy-to-open and close, highly reliable, balanced, controllable, high-pressure stop-check valve, comprising a valve body, a valve sleeve, a valve core, a valve stem, a valve cover, a transmission rod, an indicator, and a handwheel. The valve sleeve is installed in the inner cavity of the valve body, the valve sleeve is slidably connected to the valve stem, the lower end of the valve stem is connected to the valve core, and the lower end of the valve stem can move up and down in the inner cavity of the valve core to form a valve core-valve stem assembly structure; a spring seat and a spring are installed in the hole at the lower end of the valve stem, and the end of the spring seat is always in contact with the valve core under the action of the spring; the circular edge line of the lower end of the valve core and the inclined surface below the inner cavity of the valve sleeve together form a sealing pair; the valve cover is fixedly connected to the upper end of the valve body by a thread, and the valve sleeve is axially positioned and fixed by a positioning sleeve; an indicator is installed on the top of the valve cover, the transmission rod is threadedly connected to the valve cover, the upper end of the transmission rod is fixedly connected to the handwheel, and the lower end is connected to the boss at the upper end of the valve stem through a radial groove on the transmission rod.

[0009] Furthermore, the bosses at the ends of the valve stem and the spring seat are installed into the valve core groove from the side through the radial groove on the valve core.

[0010] Furthermore, the valve sleeve and the valve body are sealed by a sealing ring.

[0011] Furthermore, when the valve stem moves upward until the shaft shoulder at its lower end hits the top wall of the inner cavity of the valve core, the valve stem drives the valve core to move upward together.

[0012] Furthermore, when the hand wheel at the top of the stop check valve is rotated to open or close the valve, the transmission rod drives the valve stem to move up and down, and the valve position is indicated by the indicator at the same time.

[0013] Furthermore, the lower cavity of the control cavity formed by the valve stem and the valve sleeve is provided with a breathable structure so that no medium force acts on the annular surface between the maximum outer diameter D3 of the valve stem and the maximum outer diameter D2 of the valve core.

[0014] Furthermore, in the valve core and valve stem assembly structure, the outer diameter D1 of the valve core bottom is equal to the maximum outer diameter D2 of the valve core, so that the force of the outlet medium acting on the valve core and the valve stem is completely offset.

[0015] Furthermore, the dimensions of the valve core and valve stem satisfy πD1 2 / 4=π(D3 2 -D4 2 ) / 4, D4 is the upper shaft diameter of the valve stem, which completely offsets the force of the inlet medium on the valve core.

[0016] Furthermore, the sealing seat is installed from the top of the valve body in the form of a valve sleeve. During maintenance, the valve stem, valve core, and internal parts of the valve sleeve can all be removed from the top without disassembling the pipeline.

[0017] Furthermore, a spring is provided between the valve stem and the valve core, and the spring force presses the valve core toward the valve seat, providing a portion of the non-return sealing force.

[0018] The beneficial effects of the present invention are:

[0019] Rotate the handwheel 11 at the top of the stop check valve clockwise, and the transmission rod 9 drives the valve stem 5 and the valve core 3 to move downward, and the stop check valve is manually closed; rotate the handwheel 11 at the top of the stop check valve counterclockwise, and the transmission rod 9 moves upward. When the lower end shoulder of the transmission rod 9 hits the inner cavity top wall of the valve core 3, it drives the valve core 3 to move upward, and the stop check valve is manually opened; rotate the handwheel 11 at the top of the stop check valve to make the indicator 10 in the "check" position, and the valve core 3 is pressed against the valve sleeve 2 under the action of the spring 6 to form a reliable contact. At this time, the inlet medium acts on the valve The forces at the upper and lower ends of the rod are completely balanced, and the resultant force acting on the valve core is the sum of the spring force of the spring 6 and the force of the outlet medium, and the direction thereof is consistent with the closing direction of the stop check valve, thereby achieving reliable check; when the inlet gas pressure increases, the force acting on the lower end of the valve core 3 is greater than the resultant force of the outlet medium force and the spring force, the valve core 3 and the spring seat 4 move upward until the spring seat 4 hits the lower end face of the valve stem 5, and the valve opens for discharge. When the inlet pressure drops, the valve core 3 resumes contact with the valve sleeve 2 under the action of the spring 6, and reaches the check state again.

[0020] Therefore, the present invention utilizes a fully balanced structure, reducing the manual opening and closing torque of the stop check valve. The valve sleeve structure allows for repair or replacement of the sealing pair and all valve components without disassembling the piping, improving maintainability. A spring is installed between the valve stem and valve core, pressing the valve core against the valve sleeve, enhancing check reliability. This valve offers controllable opening and closing, reliable performance, and suitability for high-pressure applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural diagram of the high-pressure stop check valve of the present invention in the forced closing position;

[0022] Figure 2 This is a diagram of the valve core and stem assembly;

[0023] Figure 3 This is a structural diagram of the high-pressure stop check valve of the present invention;

[0024] Figure 4 It is a structural diagram of the forced opening position of the high-pressure stop check valve of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] like Figures 1 to 4 As shown, a high-reliability balanced controllable high-pressure stop check valve that is easy to open and close includes a valve body 1, a valve sleeve 2, a valve core 3, a spring seat 4, a valve stem 5, a spring 6, a positioning sleeve 7, a valve cover 8, a transmission rod 9, an indicator 10, a hand wheel 11, etc.

[0027] The valve sleeve 2, valve core 3, spring seat 4, valve stem 5 and spring 6 form a valve opening and closing fully balanced structure. The valve sleeve 2, valve core 3, spring seat 4 and spring 6 form a valve check seal structure.

[0028] The valve sleeve 2 is installed in the inner cavity of the valve body 1 and is sealed with the valve body 1 by a sealing ring. The valve core 3 and the valve stem 5 are installed in the valve sleeve 2. The circular edge line of the end of the valve core 3 and the inclined surface below the inner cavity of the valve sleeve 2 together form a sealing pair; the spring 6 and the spring seat 4 are installed in the hole at the end of the valve stem 5; the bosses at the ends of the valve stem 5 and the spring seat 4 are installed in the valve core groove from the side through the radial groove on the valve core 3; the valve stem 5 can move up and down in the inner cavity of the valve core 3. When the valve stem 5 moves upward until the shaft shoulder at its end touches the inner cavity top wall of the valve core 3, it can drive the valve core 3 to move upward together; the spring seat 4 is always under the action of the spring 6 Contact with the valve core 3; positioning sleeve 7 is installed above the valve sleeve 2 to position the valve sleeve; the lower chamber of the control chamber formed by the valve stem 5 and the valve sleeve 2 is equipped with an air vent to prevent the formation of an air spring in this chamber when the valve stem moves, which would affect the normal operation of the stop check valve. At the same time, it also ensures the reliable realization of the fully balanced function during the opening and closing process; the valve cover 8 is connected to the valve body 1 via threads, and the positioning sleeve 7 and valve sleeve 2 are fixed by plane constraints; the indicator 10 is installed on the top of the valve cover 8, and the transmission rod 9 is threadedly connected to the valve cover 8. The upper end of the transmission rod 9 is fixedly connected to the handwheel 11, and the lower end is connected to the boss at the upper end of the valve stem 5 through the radial groove on the transmission rod 9. When the handwheel 11 at the top of the stop check valve is rotated to open and close the valve, the transmission rod 9 drives the valve stem 5 to move up and down, and the valve position is indicated by the indicator 10.

[0029] In this stop check valve, the lower chamber of the control chamber formed by the valve stem 5 and the valve sleeve 2 is provided with a breathable structure, so that there is no medium force acting on the annular surface between the maximum outer diameter D3 of the valve stem 5 and the maximum outer diameter D2 of the valve core 3. In the valve core and valve stem assembly structure, D1 = D2, where D1 is the outer diameter of the bottom of the valve core 3. The force of the outlet medium acting on the valve core 3 and valve stem 5 assembly is completely offset; the dimensions of the valve core 3 and valve stem 5 meet πD1 2 / 4=π(D3 2 -D4 2 ) / 4, D4 is the upper shaft diameter of the valve stem 5, so that the force of the inlet medium acting on the valve core is completely offset, thus achieving a completely balanced design.

[0030] The valve sleeve structure is adopted for easy maintenance. The main seal seat is designed in the valve sleeve of this invention. The valve sleeve, valve core and valve stem components are all installed from the top of the valve body as a whole. When the main seal pair needs to be repaired or the seal needs to be replaced, all the parts inside the valve can be removed from the top of the stop check valve for maintenance without removing the entire stop check valve from the pipeline, which greatly improves the convenience of maintenance.

[0031] A spring is installed between the valve stem and valve core, enhancing the reliability of the check valve. The spring's force is internal to the valve core and stem assembly and therefore has no effect on the opening and closing torque of the stop check valve. When the stop check valve is in the check position, the spring force is transmitted to the valve core via the spring seat, pressing the valve core against the sealing seat and providing a portion of the check valve's sealing force. When the forces of the seawater at the outlet and the compressed air at the inlet are similar, the additional sealing force provided by the spring effectively helps the valve core and sleeve form a seal, enhancing the reliability of the check valve.

Claims

1. A highly reliable balanced controllable high-pressure stop check valve that is easy to open and close, comprising a valve body, a valve sleeve, a valve core, a valve stem, a valve cover, a transmission rod, an indicator, and a hand wheel. The valve sleeve is installed in the inner cavity of the valve body, and the valve sleeve and the valve body are sealed by a sealing ring; the valve stem is connected to the valve sleeve in a sliding fit, and the lower end of the valve stem is connected to the valve core, and the lower end of the valve stem can move up and down in the inner cavity of the valve core to form a valve core and valve stem assembly structure; a spring seat and a spring are installed in the hole at the lower end of the valve stem, and the end of the spring seat is always in contact with the valve core under the action of the spring. ; The circular edge line at the lower end of the valve core and the inclined surface below the inner cavity of the valve sleeve together form a sealing pair; the valve cover is fixedly connected to the upper end of the valve body through a thread, and the valve sleeve is axially positioned and fixed by a positioning sleeve; an indicator is installed on the top of the valve cover, the transmission rod is threadedly connected to the valve cover, the upper end of the transmission rod is fixedly connected to the handwheel, and the lower end is connected to the boss at the upper end of the valve stem through the radial groove on the transmission rod; the lower cavity of the control cavity formed by the valve stem and the valve sleeve is provided with a breathable structure, so that there is no medium force on the annular surface between the maximum outer diameter D3 of the valve stem and the maximum outer diameter D2 of the valve core.

2. The easy-to-open and close, high-reliability, balanced, controllable, high-pressure stop check valve according to claim 1, characterized in that: The bosses at the ends of the valve stem and the spring seat are installed into the valve core groove from the side through the radial groove on the valve core.

3. The easy-to-open and close, high-reliability, balanced, controllable, high-pressure stop check valve according to claim 1, characterized in that: When the valve stem moves upward until the shaft shoulder at its lower end hits the top wall surface of the inner cavity of the valve core, the valve stem drives the valve core to move upward together.

4. The easy-to-open and close, high-reliability, balanced, controllable, high-pressure stop check valve according to claim 1, characterized in that: When the hand wheel is rotated to switch the valve, the transmission rod drives the valve stem to move up and down, and the valve position is indicated by the indicator.

5. The easy-to-open and close, high-reliability, balanced, controllable, high-pressure stop check valve according to claim 1, characterized in that: The outer diameter D1 of the bottom of the valve core is equal to the maximum outer diameter D2 of the valve core, so that the force of the outlet medium acting on the valve core and the valve stem is completely offset.

6. The easy-to-open and close, high-reliability, balanced, controllable, high-pressure stop check valve according to claim 5, characterized in that: The dimensions of the valve core and valve stem meet πD1 2 / 4=π(D3 2 -D4 2 ) / 4, D1 is the outer diameter of the valve core bottom, D3 is the maximum outer diameter of the valve stem, and D4 is the shaft diameter of the upper part of the valve stem, so that the force of the inlet medium acting on the valve core is completely offset.

7. The easy-to-open and close, high-reliability, balanced, controllable, high-pressure stop check valve according to claim 1, characterized in that: The sealing seat in the valve sleeve is installed in the form of a valve sleeve from the top of the valve body. During maintenance, the valve stem, valve core, and internal parts of the valve sleeve can all be removed from the top without disassembling the pipeline.

8. The easy-to-open and close, high-reliability, balanced, controllable, high-pressure stop check valve according to claim 1, characterized in that: A spring is arranged between the valve stem and the valve core, and the spring force presses the valve core toward the valve seat to provide a part of the non-return sealing force.

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