Large-diameter top-mounted ball valve and assembly method, maintenance method and repair method thereof

Abstract

The invention discloses a large-diameter top-mounted ball valve and an assembling method, a maintaining method and a repairing method thereof.According to the large-diameter top-mounted ball valve, the structure of a valve seat assembly in the large-diameter top-mounted ball valve is improved, and a valve seat, a valve seat supporting ring and a spring seat are matched with a valve body to form three independent pressure cavities; high-pressure media can be selectively input into the different pressure cavities through communication of the injection holes and an external pressure source so as to increase the pressure in the corresponding pressure cavities, and driving of different components in the valve seat assembly is achieved so that the components can axially translate. When the large-diameter top-mounted ball valve is assembled, maintained and repaired, different pressure cavities can be pressurized according to requirements so that different parts in the valve seat assembly can move in different modes, corresponding treatment modes are selected according to requirements, and the assembling, maintaining and repairing difficulty of the large-diameter top-mounted ball valve can be effectively reduced; and meanwhile, on-line maintenance and repair of the valve are achieved, and meanwhile the sealing performance of the valve cannot be affected.

Description

Technical Field

[0001] The present invention relates to the technical field of valve equipment, in particular to a large-diameter top-mounted ball valve, an assembly method for a large-diameter top-mounted ball valve, a maintenance method for a large-diameter top-mounted ball valve and a repair method for a large-diameter top-mounted ball valve. Background Art

[0002] With the increasing demand for oil and natural gas in industrial production and residents' lives, the sizes of pipelines used in various oil and gas engineering pipelines, long-distance pipelines, and urban gas pipelines have also increased accordingly. At the same time, the equipment used to control the fluid in large-diameter pipelines has also been continuously developing towards large-scale development, and large-diameter valves have also come into being. Due to the large-scale development of valve equipment, the cost and production difficulty of this type of valve have also increased accordingly, which has put forward higher requirements for the sealing, reliability and maintainability of large-diameter valve equipment.

[0003] Large-diameter top-mounted ball valves are generally used to control fluids in large-flow, high-pressure fluid pipeline systems. Their diameters are generally above DN200. After large-diameter top-mounted ball valves are installed on site pipelines, they will basically not be disassembled in the later stage, and if the end of the valve is BW welded, they cannot be disassembled on site. When a large-diameter top-mounted ball valve leaks unexpectedly during pipeline operation, whether it is external leakage of the valve, internal leakage of the valve, or leakage of the valve stem, it cannot be disassembled and repaired on site, which will cause continuous leakage of the medium, not only causing economic losses, but also may cause safety accidents in serious cases. The time cost, labor cost and economic losses caused by replacing the entire valve are very large. In addition, as the nominal size of large-diameter top-mounted ball valves continues to increase, the size and weight of the internal parts of the valve also increase accordingly, and conventional assembly methods can hardly meet its assembly requirements; and because the initial sealing force of its valve seat is entirely provided by the spring, if the spring is accidentally stuck and cannot provide the initial sealing force, it will directly lead to the failure of the valve seal, and it is difficult to replace and repair.

[0004] The Chinese utility model patent document with announcement number CN205877255U discloses a top-mounted ball valve that can be quickly disassembled for online maintenance. The valve body is provided with valve seat hole I, valve seat hole II and valve seat hole III. Valve seat, thrust seat and fixed seat are respectively placed in valve seat hole I, valve seat hole II and valve seat hole III. The thrust seat is fixedly connected to the valve seat. The thrust seat is provided with a spring hole and a cylindrical elastic member is installed in the spring hole. The fixed seat, valve seat, thrust seat, valve seat hole I and valve seat hole II form a closed cavity, namely a pressure cavity. A through hole is provided on the upper valve body of the pressure cavity to communicate with an interface, and a quick-release connector is installed at the interface. The technical solution of this utility model improves the problem of inconvenience in online disassembly and use of existing top-mounted ball valves, and is suitable for online repair or maintenance of top-mounted ball valves of different calibers.

[0005] A Chinese invention patent application with publication number CN102777624A discloses a top-mounted online maintenance ball valve, comprising a valve body, a valve seat and an actuator, wherein the valve body comprises a hollow valve cavity; the valve seat is disposed in the valve cavity, and a convex ring is formed on its outer circumferential surface, and the outer circumferential surface of the convex ring forms a movable sealing fit with the inner circumferential surface of the valve body; the actuator is a pressure ring, which is sleeved on the outer circumferential surface of the valve seat and is relatively fixedly connected to the valve body, the pressure ring forms a sliding sealing fit with the valve seat, and the outer circumferential surface of the pressure ring forms a sliding sealing fit with the inner circumferential surface of the valve cavity; a closed pressure cavity is formed between the pressure ring, the valve body and the valve seat, and pressure channels are formed in the pressure ring, which are respectively connected to the pressure cavity and a pressure source; when a pressure medium is input into the pressure channel, the axial thrust of the pressure medium acting on the convex ring pushes the valve seat to move toward a middle part away from the valve cavity.

[0006] Although the technical solution disclosed in the above patent can realize online repair or maintenance of top-mounted ball valves, the solution of setting a single or two pressure chambers to promote the movement of the valve seat can only achieve a relatively single control method. The control of the movement of the valve seat is not sufficient to meet the maintenance needs of different fault types, and it cannot provide effective assistance for the assembly of large-diameter top-mounted ball valves, and cannot reduce the difficulty of assembling large-diameter top-mounted ball valves. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a large-diameter top-mounted ball valve which is convenient for assembly, maintenance and repair.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a large-caliber top-mounted ball valve, including a valve body, a ball, a valve cover, a valve stem and two sets of valve seat assemblies. The valve body is provided with a cavity and an upstream flow channel and a downstream flow channel connected to the cavity. The valve cover is detachably connected to the top of the valve body, the ball is rotatably arranged in the cavity of the valve body, the valve stem is fixedly connected to the top of the ball and extends upward through the valve cover, and the two sets of valve seat assemblies are respectively arranged between the upstream flow channel and the cavity and between the downstream flow channel and the cavity. The valve seat assembly can be translated along the axial direction of the flow channel in the valve body to move away from or approach the ball. The valve seat assembly includes a valve seat, a valve seat support ring and a spring seat; the valve seat support ring and the spring seat are annular structures arranged coaxially with the valve seat, the valve seat is sleeved on the valve seat support ring and fixedly connected to the valve seat support ring, the spring seat is axially movably sleeved on the valve seat, and a plurality of springs are fixed on the spring seat to form an axial limit fit with the valve seat, and the expansion and contraction direction of the spring is parallel to the expansion and contraction direction of the spring. The axial direction of the spring seat; a first pressure chamber, a second pressure chamber and a third pressure chamber which are axially arranged in sequence are formed by setting a plurality of steps on the matching surfaces of the valve body, the spring seat and the valve seat, and the valve body, the spring seat and the valve seat form an axial limit fit through the plurality of steps; the valve body is provided with a first injection hole connected to the first pressure chamber, a second injection hole connected to the second pressure chamber and a third injection hole connected to the third pressure chamber; the first injection hole, the second injection hole and the third injection hole are all openable and closable through-hole structures which can be docked with an external pressure source; injecting pressure medium into the first pressure chamber through the first injection hole can push the spring seat to axially translate in the direction of the sphere, injecting pressure medium into the second pressure chamber through the second injection hole can push the spring seat to axially translate in the direction away from the sphere and push the valve seat to axially translate in the direction of the sphere at the same time, and injecting pressure medium into the third pressure chamber through the third injection hole can push the valve seat to axially translate in the direction away from the sphere.

[0009] As an improvement of the above scheme: it also includes a chain ring that can be movably mounted on the spring seat, and a radially outward-expanding limit rib is provided at one end of the spring seat close to the sphere, and the chain ring is pressed in an annular gap formed by the limit rib and the valve body; the chain ring is an annular chain structure composed of multiple arc-shaped parts hinged in sequence.

[0010] As an improvement of the above solution: a medium control assembly consisting of a needle valve and an injection joint is provided at the openings of the first injection hole, the second injection hole and the third injection hole; the medium control assembly forms a sealing fit with the corresponding injection hole through a sealing thread.

[0011] As an improvement of the above scheme: the circumferential surface of the valve stem forms a sealing fit with the valve cover, a valve stem sealing ring is sleeved on the circumferential surface of the valve stem, and anti-blowout rings are sleeved on the upper and lower parts of the valve stem sealing ring. The anti-blowout ring forms an interlocking fit with the valve stem sealing ring and the valve cover at the same time.

[0012] As an improvement to the above solution: a graphite filler is provided between the matching surfaces of the valve stem sealing ring and the valve stem, and a sealing portion of the valve cover is filled with a graphite gasket.

[0013] As an improvement of the above scheme: it also includes a stem grease injection hole, a joint grease injection hole and a ball grease injection hole arranged on the valve cover; the stem grease injection hole penetrates the valve cover and extends to be connected with two stem oil storage grooves arranged on the inner and outer side surfaces of the valve stem sealing ring, and the two stem oil storage grooves are connected through a channel penetrating the valve stem sealing ring; the joint grease injection hole penetrates the valve cover and extends to be connected with the joint oil storage groove arranged between the valve cover and the valve body; the ball grease injection hole penetrates the valve cover and extends to be connected with the ball oil storage groove arranged between the valve seat and the valve seat support ring, and the ball oil storage groove extends to the end surface of the valve seat support ring close to the ball; the orifices of the stem grease injection hole, the joint grease injection hole and the ball grease injection hole are all provided with grease injection valves, and the insides of the stem grease injection hole, the joint grease injection hole and the ball grease injection hole are all provided with grease injection check valves, and the grease injection check valve has a direction away from the grease injection valve as the opening direction.

[0014] As an improvement to the above solution: the end surface of the valve seat close to the sphere is coated with an alloy coating.

[0015] The present invention also discloses an assembly method of a large-diameter top-mounted ball valve, which is performed by using the large-diameter top-mounted ball valve as described above and following the steps:

[0016] S11, installing two sets of valve seat assemblies between the upstream flow channel and the cavity and between the downstream flow channel and the cavity of the valve body respectively;

[0017] S12. Assemble the ball into the cavity of the valve body so that the minimum distance between the ball and the end face of the valve seat is maintained at 10 to 30 mm;

[0018] S13, connect the first injection hole to the external pressure source, start the external pressure source to continuously pressurize so that the first pressure chamber is filled with pressure medium; according to the formula V1 = L1 × π × (R1 2 -R2 2 ), Calculate the required medium pressure P1, where R1 is the outer ring radius of the first pressure chamber, R2 is the inner ring radius of the first pressure chamber, L1 is the stroke of the first pressure chamber, V1 is the volume of the first pressure chamber, f1 is the friction force of the entire valve seat assembly, N is the number of springs assembled on the spring seat, and K is the elastic force provided by a single spring; pressurize until the pressure in the first pressure chamber rises to ≥ P1, push the valve seat assembly to translate toward the ball as a whole, continue to pressurize and keep the pressure not lower than P1, so that the valve seat is close to the ball to form a sealing fit;

[0019] S14, assemble the chain ring between the valve body and the spring seat, then close the first injection hole, and complete the assembly of the valve cover and the valve stem in sequence.

[0020] The present invention also discloses a maintenance method for a large-diameter top-mounted ball valve, using the large-diameter top-mounted ball valve as described above, and adopting different maintenance plans according to the fault type;

[0021] When the fault is that the valve leaks out, grease is injected into the grease injection hole of the joint through the grease injection valve, so that the oil storage tank of the joint is filled with sealing grease;

[0022] When the fault is caused by damage to the valve stem sealing ring, remove the blowout prevention ring and the valve stem sealing ring on the upper part of the valve stem sealing ring, use the blowout prevention ring on the lower part of the valve stem sealing ring to prevent the valve stem from spraying, and replace the graphite packing and graphite gasket;

[0023] When the fault is internal leakage of the valve, grease is injected into the grease injection hole of the ball through the grease injection valve to fill the ball oil storage tank with sealing grease;

[0024] When the fault is that the spring on the spring seat is stuck and fails, the first injection hole is connected to the external pressure source, and the external pressure source is started to pressurize the first pressure chamber so that the valve seat is close to the ball.

[0025] The present invention also discloses a maintenance method for a large-diameter top-mounted ball valve, which is performed by using the large-diameter top-mounted ball valve as described above and following the steps below:

[0026] S21, remove the valve cover and hoist it out;

[0027] S22, connect the first injection hole to the external pressure source, start the external pressure source to continuously pressurize so that the first pressure chamber is filled with pressure medium; according to the formula V1 = L1 × π × (R1 2 -R2 2 ), Calculate the required medium pressure P1, where R1 is the outer ring radius of the first pressure chamber, R2 is the inner ring radius of the first pressure chamber, L1 is the stroke of the first pressure chamber, V1 is the volume of the first pressure chamber, f1 is the friction force of the entire valve seat assembly, N is the number of springs assembled on the spring seat, and K is the elastic force provided by a single spring; pressurize until the pressure in the first pressure chamber rises to ≥ P1, push the valve seat assembly to translate toward the ball as a whole, and remove the chain link from the valve body after the chain link is loosened;

[0028] S23, disconnecting the first injection hole from the external pressure source, and opening the first injection hole to release the pressure in the first pressure chamber;

[0029] S24, connect the second injection hole to the external pressure source, start the external pressure source to continuously pressurize so that the second pressure chamber is filled with pressure medium; according to the formula V2 = L2 × π × (R3 2 -R4 2 ), Calculate the required medium pressure P2, where R3 is the outer ring radius of the second pressure chamber, R4 is the inner ring radius of the second pressure chamber, L2 is the stroke of the second pressure chamber, V2 is the volume of the second pressure chamber, and f2 is the friction force of the entire valve seat assembly; pressurize until the pressure in the second pressure chamber rises to ≥ P2, pushing the spring seat to translate away from the ball, and continue to pressurize until the spring seat retreats to abut against the valve body in the axial direction;

[0030] S25, closing the first injection hole to form a closed inner cavity of the first pressure chamber, then disconnecting the second injection hole from the external pressure source and opening the second injection hole to release the pressure of the second pressure chamber;

[0031] S26, connect the third injection hole to the external pressure source, start the external pressure source to continuously pressurize so that the third pressure chamber is filled with pressure medium; according to the formula V3 = L3 × π × (R5 2 -R6 2 ), Calculate the required medium pressure P3, where R5 is the outer ring radius of the third pressure chamber, R6 is the inner ring radius of the third pressure chamber, L3 is the stroke of the third pressure chamber, V3 is the volume of the third pressure chamber, and f3 is the friction force of the entire valve seat assembly; pressurize until the pressure in the third pressure chamber rises to ≥ P3, pushing the valve seat to move in a direction away from the ball, and continue to pressurize until the valve seat retreats to abut against the valve body in the axial direction, and the valve seat assembly is completely separated from the ball with a gap of 10 to 30 mm;

[0032] S27. Remove the ball and hoist it out of the cavity of the valve body;

[0033] S28. Connect the first injection hole to the external pressure source, start the external pressure source to continuously increase the pressure so that the pressure in the first pressure chamber rises to ≥ P1, push the valve seat assembly to move horizontally toward the sphere as a whole, and finally disassemble and hoist other parts that need to be repaired.

[0034] The beneficial effects of the present invention are as follows: the present invention improves the structure of the valve seat assembly in the large-diameter top-mounted ball valve, and forms three independent pressure chambers through the cooperation of the valve seat, the valve seat support ring and the spring seat with the valve body, and three injection holes are arranged on the valve body to be connected with the three pressure chambers respectively, and the high-pressure medium can be selectively input into different pressure chambers through the injection holes to be connected with the external pressure source to increase the pressure in the corresponding pressure chamber, thereby realizing the driving of different components in the valve seat assembly to make them perform axial translation with selectable direction, and when the large-diameter top-mounted ball valve is assembled, maintained and repaired, different pressure chambers can be pressurized according to needs to make different components in the valve seat assembly realize different movement modes, thereby selecting the corresponding processing method according to needs, which can effectively reduce the difficulty of assembly, maintenance and repair of the large-diameter top-mounted ball valve, make different processing work more convenient, and at the same time realize online maintenance and repair of the valve without affecting the sealing performance of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a front cross-sectional view of a large-diameter top-mounted ball valve in the present invention;

[0036] Figure 2 It is a top cross-sectional view of a large-diameter top-mounted ball valve in the present invention;

[0037] Figure 3 It is a side cross-sectional view of a large-diameter top-mounted ball valve in the present invention;

[0038] Figure 4 for Figure 1 A local enlarged schematic diagram of the middle A;

[0039] Figure 5 for Figure 1 A partial enlarged schematic diagram of point B in the middle;

[0040] Figure 6 for Figure 2 A partial enlarged schematic diagram of the center C, with the first pressure chamber in a pressurized state;

[0041] Figure 7 for Figure 2 A partial enlarged schematic diagram of the middle C, with the second pressure chamber in a pressurized state;

[0042] Figure 8 for Figure 2 A partial enlarged schematic diagram of point C in the middle, with the third pressure chamber in a pressurized state.

[0043] The markings in the figure are: 100-valve body, 111-first injection hole, 112-second injection hole, 113-third injection hole, 120-medium control component, 130-joint oil storage tank, 200-ball, 300-valve cover, 310-graphite gasket, 320-valve stem grease injection hole, 330-joint grease injection hole, 340-ball grease injection hole, 400-valve stem, 410-valve stem sealing ring, 411 - Valve stem oil storage tank, 420- anti-blowout ring, 430- graphite packing, 500- valve seat assembly, 510- valve seat, 511- alloy coating, 520- valve seat support ring, 530- spring seat, 531- spring, 541- first pressure chamber, 542- second pressure chamber, 543- third pressure chamber, 550- chain link, 560- ball oil storage tank, 610- grease injection valve, 620- grease injection check valve. DETAILED DESCRIPTION

[0044] In order to facilitate the understanding of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0045] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “front”, “rear”, “left”, “right”, “up”, “down” and “inside” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of description. They do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0046] like Figures 1 to 3As shown, the large-caliber top-mounted ball valve disclosed in the present invention includes a valve body 100, a ball 200, a valve cover 300, a valve stem 400 and a valve seat assembly 500. The valve body 100 is an integrated integral valve body, and a cavity for accommodating the ball 200 is provided inside the valve body 100. The ball 200 is rotatably arranged in the cavity of the valve body 100. The two ends of the valve body 100 are respectively provided with an upstream flow channel and a downstream flow channel connected to the cavity, and the ball 200 is provided with a medium channel that can be connected with the upstream flow channel and the downstream flow channel; when the ball 200 is rotated until the medium channel is fully connected with the upstream flow channel and the downstream flow channel, the valve is in a fully open state, and the medium flows; when the ball 200 is rotated until the medium channel is completely misaligned with the upstream flow channel and the downstream flow channel, the valve is in a fully closed state, and the medium is cut off. The valve cover 300 is a circular valve cover that can rotate along the vertical center axis of the valve body 100. Both the valve body 100 and the valve cover 300 adopt a casting structure to save the overall production cost of the valve, and can facilitate the overall molding of the valve and reduce the subsequent mechanical processing work. The valve stem 400 is vertically arranged along the vertical center axis of the valve body 100. The lower end of the valve stem 400 is fixedly connected to the top of the ball 200. The upper end of the valve stem 400 extends upward through the valve cover 300. The upper end of the valve stem 400 is connected to the actuator to drive the valve stem 400 to rotate through the actuator to drive the ball 200 to rotate. Two groups of valve seat assemblies 500 are used in the present invention, and the two groups of valve seat assemblies 500 are respectively arranged between the upstream flow channel and the cavity and between the downstream flow channel and the cavity. The valve seat assembly 500 can translate along the axial direction of the flow channel in the valve body 100 to move away from or approach the ball 200. When the valve seat assembly 500 is pressed against the ball 200, a sealing fit is achieved. When the valve seat assembly 500 is separated from the ball 200, the ball 200 can be rotated.

[0047] Specifically, Figures 6 to 8As shown, the valve seat assembly 500 used in the present invention includes a valve seat 510, a valve seat support ring 520 and a spring seat 530. The valve seat support ring 520 and the spring seat 530 are both annular structures coaxially arranged with the valve seat 510, the valve seat 510 is sleeved on the valve seat support ring 520 and fixedly connected with the valve seat support ring 520 to form an integral structure, and the spring seat 530 is sleeved on the valve seat 510, and the spring seat 530 is a movable structure, and the spring seat 530 can axially translate along the outer peripheral surface of the valve seat 510. A plurality of springs 531 are installed on the spring seat 530. The plurality of springs 531 are evenly distributed in a ring shape on the spring seat 530 with the axis of the spring seat 530 as the center line. Spring holes corresponding to the springs 531 are provided on the spring seat 530. One end of the spring 531 is fixedly connected in the corresponding spring hole. The other end of the spring 531 is a movable end extending out of the spring hole. The movable end of the spring 531 forms an axial limit fit with the valve seat 510. The expansion and contraction direction of the spring 531 is parallel to the axial direction of the spring seat 530. The movable end of the spring 531 can be pressed against the valve seat 510 to provide a pre-tightening force to improve the sealing fit effect between the valve seat 510 and the ball 200. Since the valve seat 510 is a component that directly contacts the sphere 200, the end surface of the valve seat 510 that contacts the sphere 200 is prone to wear. Therefore, in the present invention, this end surface of the valve seat 510 is reinforced, and an alloy coating 511 is coated on the end surface of the valve seat 510 close to the sphere 200. The alloy coating 511 can be made of TCC material or STL material with good wear resistance and sealing performance.

[0048] In order to reduce the difficulty of assembling, maintaining and repairing the valve, the present invention improves the structure of the valve and sets the valve seat assembly 500 as a piston-type valve seat assembly in which multiple pressure chambers cooperate with each other to realize that different components in the piston assembly 500 can move independently. Figure 2 , Figures 6 to 8As shown, three through holes penetrating the valve body 100 to the cavity are provided on the valve body 100 to form injection holes. The outer opening of the injection hole is connected to a medium control assembly 120 through an NPT sealing thread. The medium control assembly 120 consists of a needle valve and an injection joint. The injection hole can be connected to an external pressure source through the injection joint. The external pressure source can be a hydraulic pressure source or a pneumatic pressure source. The opening and closing of the injection hole and the flow rate of the injected medium can be controlled by the needle valve. The three injection holes are the first injection hole 111, the second injection hole 112 and the third injection hole 113. At the same time, a plurality of steps are provided on the inner side surface of the valve body 100 and the matching surface of the spring 530 and the valve seat 510, so that the first pressure chamber 541, the second pressure chamber 542 and the third pressure chamber 543 arranged axially in sequence are formed in the valve seat assembly 500, and the valve body 100, the spring seat 530 and the valve seat 510 form a mutual axial limit fit through these steps. The first pressure chamber 541, the second pressure chamber 542 and the third pressure chamber 543 are all independent chambers. The first pressure chamber 541 is connected to the first injection hole 111, the second pressure chamber 542 is connected to the second injection hole 112, and the third pressure chamber 543 is connected to the third injection hole 113. The pressure medium can be injected into the corresponding pressure chamber through the injection hole to increase the pressure in the pressure chamber, and the corresponding pressure chamber can also be depressurized through the injection hole, so as to realize the piston function to push the corresponding component to move; for example, injecting the pressure medium into the first pressure chamber 541 through the first injection hole 111 can push the spring seat 530 to axially translate in the direction of the ball 200, injecting the pressure medium into the second pressure chamber 542 through the second injection hole 112 can push the spring seat 530 to axially translate in the direction away from the ball 200 and push the valve seat 510 to axially translate in the direction of the ball 200, and injecting the pressure medium into the third pressure chamber 543 through the third injection hole 113 can push the valve seat 510 to axially translate in the direction away from the ball 200. By controlling the pressure in different pressure chambers, corresponding pressurization or pressure relief operations can be selected according to the assembly, maintenance or repair requirements of the valve, thereby reducing the difficulty of assembly, maintenance or repair of the valve and making it more targeted. During maintenance, more appropriate operations can be performed by controlling the pressure of different pressure chambers according to different damage types.

[0049] Further, such as Figure 6As shown, the present invention also sets a chain ring 550 on the spring seat 530. The chain ring 550 is an annular chain structure composed of multiple arc-shaped parts hinged in sequence, so that the chain ring 550 becomes a deformable hard and flexible structure, which is convenient for assembling the chain ring 550 on the spring seat 530. The assembly of the chain ring 550 on the spring seat 530 is realized by a chimeric method. The end of the spring seat 530 close to the ball 200 is provided with a radially outward-expanding limit rib. The limit rib cooperates with the inner side of the valve body 100 to form an annular installation groove that can accommodate the chain ring 550. The chain ring 550 is installed in the annular installation groove and is pressed into the annular installation groove by the upper limit rib of the spring seat 530. The width of the annular mounting groove can be changed by axial translation of the spring seat 530. When the valve is repaired or maintained, the chain ring 550 can be removed from the annular mounting groove, and then the spring seat 530 can be moved to abut against the valve body 100. At this time, the annular mounting groove is in a non-existent state. After the chain ring 550 is assembled, the movement of the spring seat 530 can be limited by the chain ring 550 to prevent the spring seat 530 from retreating, thereby preventing the sealing from failing due to the retreat of the spring seat 530 after the pressure chamber is depressurized.

[0050] In order to improve the sealing effect of the matching point between the valve stem 400 and the valve cover 300, the present invention sets a multiple sealing structure between the valve stem 400 and the valve cover 300. Specifically, Figure 1 and Figure 4 As shown, a stem sealing ring 410 is sleeved on the circumference of the valve stem 400, and anti-blowout rings 420 are arranged on the upper and lower parts of the stem sealing ring 410. The matching surfaces of the stem sealing ring 410 and the valve cover 300 are provided with annular grooves adapted to the anti-blowout ring 420, so that the anti-blowout ring 420 can simultaneously form a chimeric fit with the stem sealing ring 410 and the valve cover 300; the two anti-blowout rings 420 arranged on the upper and lower parts of the stem sealing ring 410 form a double-layer spray-release measure, which can effectively ensure that the valve stem 400 will not be sprayed out by the internal pressure of the valve body 100, making the valve safer and more secure; the anti-blowout ring 420 can adopt a four-open ring to improve its assembly convenience. In addition, a graphite filler 430 is provided between the matching surfaces of the stem sealing ring 410 and the valve stem 400, and a graphite gasket 310 is filled in the sealing part of the valve cover 300.

[0051] Further, such as Figures 4 to 8As shown, the present invention also provides a plurality of grease injection holes to inject grease into various matching parts of the valve. When a leakage failure occurs in the valve, emergency grease injection can be performed on different parts through the grease injection holes to achieve an emergency sealing effect. The grease injection holes include a stem grease injection hole 320, a joint grease injection hole 330 and a ball grease injection hole 340 arranged on the valve cover 300; the stem grease injection hole 320 penetrates the valve cover and extends to communicate with two stem oil storage grooves 411 arranged on the inner and outer side surfaces of the stem sealing ring 410, and the two stem oil storage grooves 411 are connected through a channel penetrating the stem sealing ring 410; the joint grease injection hole 330 penetrates the valve cover 300 and extends to communicate with the joint oil storage groove 130 arranged between the valve cover 300 and the valve body 100; the ball grease injection hole 340 penetrates the valve cover 300 and extends to communicate with the ball oil storage groove 560 arranged between the valve seat 510 and the valve seat support ring 520, and the ball oil storage groove 560 extends to the end surface of the valve seat support ring 520 close to the ball 200. In order to control the grease injection work of the grease injection holes, the present invention is provided with grease injection valves 610 at the openings of the valve stem grease injection hole 320, the joint grease injection hole 330 and the ball grease injection hole 340, and the grease injection valves 610 can be used to control the opening and closing of the corresponding grease injection holes and the grease injection flow rate; and grease injection check valves 620 are provided inside the valve stem grease injection hole 320, the joint grease injection hole 330 and the ball grease injection hole 340, and the grease injection check valves 620 take the direction away from the grease injection valve 610 as the opening direction, and the grease injection check valves 620 can be provided to prevent the sealing grease in the corresponding grease injection holes from flowing back.

[0052] The present invention also discloses an assembly method corresponding to the above-mentioned large-diameter top-mounted ball valve, and the assembly method is implemented in accordance with the following steps in sequence:

[0053] S11, installing two sets of valve seat assemblies 500 between the upstream flow channel and the cavity and between the downstream flow channel and the cavity of the valve body 100 respectively. In this step, firstly install the spring 531 in the spring seat 530, and set the number of the springs 531 used to be N. Then, hoist and assemble the spring seat 530 into the cavity of the valve body 100, and then hoist and assemble the whole structure consisting of the valve seat 510 and the valve seat support ring 520 into the valve seat hole in the valve body 100, so that the spring seat 530 is sleeved on the valve seat 510;

[0054] S12, assemble the ball 200 into the cavity of the valve body 100, so that the minimum distance between the ball 200 and the end surface of the valve seat 510 is maintained at 10-30 mm, so as to ensure that the ball 200 can be smoothly assembled into the cavity of the valve body 100. At this time, the state of the valve seat assembly 500 is as follows: Figure 8 As shown;

[0055] S13, connect the first injection hole 111 to the external pressure source, start the external pressure source to continuously pressurize so that the first pressure chamber 541 is filled with pressure medium; according to the formula V1 = L1 × π × (R1 2 -R2 2 ), Calculate the required medium pressure P1, where R1 is the outer ring radius of the first pressure chamber 541, R2 is the inner ring radius of the first pressure chamber 541, L1 is the stroke of the first pressure chamber 541, V1 is the volume of the first pressure chamber 541, f1 is the friction force of the entire valve seat assembly 500, N is the number of springs 531 assembled on the spring seat 530, and K is the elastic force provided by a single spring 531; pressurize until the pressure in the first pressure chamber 541 rises to ≥ P1, push the valve seat assembly 500 to translate toward the ball 200 as a whole, continue to pressurize and keep the pressure not lower than P1, so that the valve seat 510 is tightly against the ball 200 to form a sealing fit;

[0056] S14, assemble the chain ring 550 between the valve body 100 and the spring seat 530, and use the chain ring 550 to axially limit the spring seat 530 to prevent the spring seat 530 from retreating, and then close the first injection hole 111, and complete the assembly of the valve cover 300 and the valve stem 400 in sequence. After the assembly is completed, the state of the valve seat assembly 500 is as follows: Figure 6 shown.

[0057] The present invention also discloses a maintenance method corresponding to the above-mentioned large-diameter top-mounted ball valve. The maintenance method is online maintenance, and different maintenance plans can be adopted for the valve according to the fault type of the valve at the valve working site.

[0058] When the fault is that the valve leaks, grease is injected into the grease injection hole 330 of the joint part through the grease injection valve 610, so that the oil storage tank 130 of the joint part is filled with sealing grease. Figure 5 As shown, at this time, the joint between the valve body 100 and the valve cover 300 can be urgently sealed to prevent the valve from further leaking.

[0059] When the fault is that the valve stem sealing ring 410 is damaged, remove the blowout prevention ring 420 and the valve stem sealing ring 410 on the upper part of the valve stem sealing ring 410, such as Figure 4 As shown, at this time, the blowout prevention ring 420 at the lower part of the valve stem sealing ring 410 can be used to prevent the valve stem 400 from spraying, and the graphite packing 430 and the graphite gasket 310 are replaced;

[0060] When the fault is internal leakage of the valve, grease is injected into the ball grease injection hole 340 through the grease injection valve 610, so that the ball oil storage tank 560 is filled with sealing grease. Figure 6 As shown, at this time, the matching surface between the valve seat assembly 500 and the ball 200 can be metal-sealed to prevent further internal leakage of the valve;

[0061] When the fault is that the spring 531 on the spring seat 530 is stuck and fails, such as Figure 6 As shown, the first injection hole 111 is connected to an external pressure source, and the external pressure source is started to pressurize the first pressure chamber 541 so that the valve seat 510 is tightly attached to the ball 200 .

[0062] The present invention also discloses a maintenance method corresponding to the above-mentioned large-diameter top-mounted ball valve, and the maintenance method is implemented in accordance with the following steps in sequence:

[0063] S21, remove the fasteners and connectors on the valve cover 300 that are used to connect with the valve body 100, and then disassemble the valve cover 300 and hoist it out;

[0064] S22, such as Figure 6 As shown, the first injection hole 111 is connected to the external pressure source, and the external pressure source is started to continuously pressurize so that the first pressure chamber 541 is filled with pressure medium; according to the formula V1=L1×π×(R1 2 -R2 2 ), Calculate the required medium pressure P1, where R1 is the outer ring radius of the first pressure chamber 541, R2 is the inner ring radius of the first pressure chamber 541, L1 is the stroke of the first pressure chamber 541, V1 is the volume of the first pressure chamber 541, f1 is the friction force of the entire valve seat assembly 500, N is the number of springs 531 assembled on the spring seat 530, and K is the elastic force provided by a single spring 531; pressurize until the pressure in the first pressure chamber 541 rises to ≥ P1, push the valve seat assembly 500 to translate toward the ball 200 as a whole, and remove the chain link 550 from the valve body 100 after the chain link 550 is loosened;

[0065] S23, disconnecting the first injection hole 111 from the external pressure source, opening the needle valve in the medium control assembly corresponding to the first injection hole 111 to release the pressure in the first pressure chamber 541, and freely connecting it to the external environment;

[0066] S24, connect the second injection hole 112 to the external pressure source, start the external pressure source to continuously pressurize so that the second pressure chamber 542 is filled with pressure medium; according to the formula V2 = L2 × π × (R3 2 -R4 2 ), The required medium pressure P2 is calculated, where R3 is the outer ring radius of the second pressure chamber 542, R4 is the inner ring radius of the second pressure chamber 542, L2 is the stroke of the second pressure chamber 542, V2 is the volume of the second pressure chamber 542, and f2 is the friction force of the entire valve seat assembly 500; pressurize until the pressure in the second pressure chamber 542 rises to ≥ P2, pushing the spring seat 530 to translate in a direction away from the ball 200, and continue to pressurize until the spring seat 530 retreats to abut against the valve body 100 in the axial direction. At this time, the state of the valve seat assembly 500 is as follows: Figure 7 As shown;

[0067] S25, closing the first injection hole 111 to form a closed inner cavity of the first pressure chamber 541, then disconnecting the second injection hole 112 from the external pressure source and opening the needle valve in the medium control assembly corresponding to the second injection hole 112 to release the pressure of the second pressure chamber 542, so that the second pressure chamber 542 is freely connected to the external environment;

[0068] S26, connect the third injection hole 113 to the external pressure source, start the external pressure source to continuously pressurize so that the third pressure chamber 543 is filled with pressure medium; according to the formula V3 = L3 × π × (R5 2 -R6 2 ), The required medium pressure P3 is calculated, where R5 is the outer ring radius of the third pressure chamber 543, R6 is the inner ring radius of the third pressure chamber 543, L3 is the stroke of the third pressure chamber 543, V3 is the volume of the third pressure chamber 543, and f3 is the friction force of the entire valve seat assembly 500; pressurize until the pressure in the third pressure chamber 543 rises to ≥ P3, pushing the valve seat 510 to translate in the direction away from the ball 200, and continue to pressurize until the valve seat 510 retreats to abut against the valve body 100 in the axial direction, the valve seat assembly 500 is completely separated from the ball 200 and there is a gap of 10 to 30 mm. At this time, the state of the valve seat assembly 500 is as follows: Figure 8 As shown; through the volume V1 of the first pressure chamber 541, the volume V2 of the second pressure chamber 542 and the volume V3 of the third pressure chamber 543 calculated in steps S22, S24 and S26, the capacity of the pressure medium required by the entire system during operation can be calculated;

[0069] S27, dismantling the ball 200 and hoisting it out of the cavity of the valve body 100;

[0070] S28. Connect the first injection hole 111 to the external pressure source, start the external pressure source to continuously pressurize so that the pressure in the first pressure chamber 541 rises to ≥ P1, push the valve seat assembly 500 to translate toward the sphere 200 as a whole, and finally disassemble and hoist other parts that need to be repaired, so that the damaged parts of the valve can be repaired and replaced.

Claims

1. A large-caliber top-mounted ball valve, comprising a valve body (100), a ball (200), a valve cover (300), a valve stem (400) and two sets of valve seat assemblies (500), wherein a cavity and an upstream flow channel and a downstream flow channel communicated with the cavity are provided in the valve body (100), the valve cover (300) is detachably connected to the top of the valve body (100), the ball (200) is rotatably arranged in the cavity of the valve body (100), the valve stem (400) is fixedly connected to the top of the ball (200) and extends upward through the valve cover (300), the two sets of valve seat assemblies (500) are respectively arranged between the upstream flow channel and the cavity and between the downstream flow channel and the cavity, the valve seat assembly (500) can translate along the axial direction of the flow channel in the valve body (100) to move away from or close to the ball (200), and is characterized in that: The valve seat assembly (500) comprises a valve seat (510), a valve seat support ring (520) and a spring seat (530); the valve seat support ring (520) and the spring seat (530) are annular structures coaxially arranged with the valve seat (510); the valve seat (510) is sleeved on the valve seat support ring (520) and fixedly connected to the valve seat support ring (520); the spring seat (530) is sleeved on the valve seat (510) in an axially movably manner; a plurality of springs shaped in the same manner as the valve seat (510) are fixed on the spring seat (530). A spring (531) is provided to form an axial limit fit, and the expansion and contraction direction of the spring (531) is parallel to the axial direction of the spring seat (530); a first pressure chamber (541), a second pressure chamber (542) and a third pressure chamber (543) arranged axially in sequence are formed on the matching surfaces of the valve body (100), the spring seat (530) and the valve seat (510) by arranging a plurality of steps, and the valve body (100), the spring seat (530) and the valve seat (510) form an axial limit fit through the plurality of steps; the valve The body (100) is provided with a first injection hole (111) communicating with the first pressure chamber (541), a second injection hole (112) communicating with the second pressure chamber (542), and a third injection hole communicating with the third pressure chamber (543); the first injection hole (111), the second injection hole (112), and the third injection hole (113) are all openable and closable through-hole structures that can be connected to an external pressure source; the pressure medium injected into the first pressure chamber (541) through the first injection hole (111) can push the elastic The spring seat (530) is axially translated toward the spherical body (200). By injecting a pressure medium into the second pressure chamber (542) through the second injection hole (112), the spring seat (530) is pushed to axially translate in a direction away from the spherical body (200) and the valve seat (510) is pushed to axially translate in a direction toward the spherical body (200). By injecting a pressure medium into the third pressure chamber (543) through the third injection hole (113), the valve seat (510) is pushed to axially translate in a direction away from the spherical body (200).

2. The large-diameter top-entry ball valve according to claim 1, characterized in that: It also includes a chain link (550) movably mounted on the spring seat (530); one end of the spring seat (530) close to the sphere (200) is provided with a radially outwardly expanding limit rib; the chain link (550) is pressed into an annular gap formed by the limit rib and the valve body (100); the chain link (550) is an annular chain structure composed of multiple arc-shaped parts hinged in sequence.

3. The large-diameter top-mounted ball valve according to claim 2, characterized in that: A medium control assembly (120) consisting of a needle valve and an injection joint is provided at the openings of the first injection hole (111), the second injection hole (112) and the third injection hole (113); the medium control assembly (120) forms a sealing fit with the corresponding injection hole via a sealing thread.

4. The large-diameter top-mounted ball valve according to claim 2, characterized in that: The circumferential surface of the valve stem (400) forms a sealing fit with the valve cover (300), a valve stem sealing ring (410) is sleeved on the circumferential surface of the valve stem (400), and anti-blowout rings (420) are sleeved on the upper and lower parts of the valve stem sealing ring (410), and the anti-blowout ring (420) forms a chimeric fit with the valve stem sealing ring (410) and the valve cover (300).

5. The large-diameter top-entry ball valve according to claim 4, characterized in that: A graphite filler (430) is provided between the matching surfaces of the valve stem sealing ring (410) and the valve stem (400), and a sealing portion of the valve cover (300) is filled with a graphite gasket (310).

6. The large-diameter top-entry ball valve according to claim 4, characterized in that: The valve body (300) further comprises a valve stem grease injection hole (320), a joint grease injection hole (330) and a ball grease injection hole (340) arranged on the valve cover (300); the valve stem grease injection hole (320) penetrates the valve cover and extends to communicate with two valve stem oil storage grooves (411) arranged on the inner and outer side surfaces of the valve stem sealing ring (410); the two valve stem oil storage grooves (411) are communicated through a channel penetrating the valve stem sealing ring (410); the joint grease injection hole (330) penetrates the valve cover (300) and extends to communicate with the joint oil storage groove (130) arranged between the valve cover (300) and the valve body (100); the ball grease injection hole (340) penetrates the valve cover (300) and extends to communicate with the joint oil storage groove (130) arranged between the valve cover (300) and the valve body (100); 0) and extends to communicate with the ball oil storage groove (560) arranged between the valve seat (510) and the valve seat support ring (520), and the ball oil storage groove (560) extends to the end surface of the valve seat support ring (520) close to the ball (200); the orifices of the valve stem grease injection hole (320), the joint grease injection hole (330) and the ball grease injection hole (340) are all provided with grease injection valves (610), and the insides of the valve stem grease injection hole (320), the joint grease injection hole (330) and the ball grease injection hole (340) are all provided with grease injection check valves (620), and the grease injection check valves (620) are opened in the direction away from the grease injection valve (610).

7. The large-diameter top-entry ball valve according to claim 2, characterized in that: An alloy coating (511) is coated on the end surface of the valve seat (510) close to the sphere (200).

8. Assembly method of large-diameter top-mounted ball valve, characterized in that: Using the large-diameter top-mounted ball valve as described in any one of claims 2 to 7, proceed according to the following steps: S11, installing two sets of valve seat assemblies (500) between the upstream flow channel and the cavity and between the downstream flow channel and the cavity of the valve body (100), respectively; S12, assembling the ball (200) into the cavity of the valve body (100) so that the minimum distance between the ball (200) and the end surface of the valve seat (510) is maintained at 10 to 30 mm; S13, connecting the first injection hole (111) to an external pressure source, starting the external pressure source to continuously pressurize so that the first pressure chamber (541) is filled with pressure medium; according to the formula V1 = L1 × π × (R1 2 -R2 2 ), Calculate the required medium pressure P1, where R1 is the outer ring radius of the first pressure chamber (541), R2 is the inner ring radius of the first pressure chamber (541), L1 is the stroke of the first pressure chamber (541), V1 is the volume of the first pressure chamber (541), f1 is the friction force of the entire valve seat assembly (500), N is the number of springs (531) mounted on the spring seat (530), and K is the elastic force provided by a single spring (531); pressurize until the pressure in the first pressure chamber (541) rises to ≥ P1, pushing the valve seat assembly (500) to translate toward the ball (200) as a whole, and continue to pressurize and maintain the pressure not less than P1, so that the valve seat (510) is tightly attached to the ball (200) to form a sealing fit; S14, assemble the chain link (550) between the valve body (100) and the spring seat (530), then close the first injection hole (111), and complete the assembly of the valve cover (300) and the valve stem (400) in sequence. 9.Maintenance method of large-diameter top-mounted ball valve, characterized by: Using the large-diameter top-mounted ball valve as described in claim 6, different maintenance plans are adopted according to the type of failure; When the fault is that the valve leaks out, grease is injected into the grease injection hole (330) of the joint part through the grease injection valve (610) so that the oil storage groove (130) of the joint part is filled with sealing grease; When the fault is that the valve stem sealing ring (410) is damaged, the blowout prevention ring (420) and the valve stem sealing ring (410) on the upper part of the valve stem sealing ring (410) are removed, and the blowout prevention ring (420) on the lower part of the valve stem sealing ring (410) is used to prevent the valve stem (400) from being sprayed, and the graphite packing (430) and the graphite gasket (310) are replaced; When the fault is that the valve has internal leakage, grease is injected into the grease injection hole (340) of the ball through the grease injection valve (610) so that the ball oil storage tank (560) is filled with sealing grease; When the fault is that the spring (531) on the spring seat (530) is stuck and fails, the first injection hole (111) is connected to the external pressure source, and the external pressure source is started to pressurize the first pressure chamber (541), so that the valve seat (510) is tightly attached to the ball (200).

10. The maintenance method of large-diameter top-mounted ball valve is characterized by: Using the large-diameter top-mounted ball valve as described in any one of claims 2 to 7, proceed according to the following steps: S21, remove the valve cover (300) and hoist it out; S22, connecting the first injection hole (111) to an external pressure source, starting the external pressure source to continuously pressurize so that the first pressure chamber (541) is filled with pressure medium; according to the formula V1 = L1 × π × (R1 2 -R2 2 ), Calculate the required medium pressure P1, where R1 is the outer ring radius of the first pressure chamber (541), R2 is the inner ring radius of the first pressure chamber (541), L1 is the stroke of the first pressure chamber (541), V1 is the volume of the first pressure chamber (541), f1 is the friction force of the entire valve seat assembly (500), N is the number of springs (531) mounted on the spring seat (530), and K is the elastic force provided by a single spring (531); pressurize until the pressure in the first pressure chamber (541) rises to ≥ P1, push the valve seat assembly (500) to translate toward the ball (200) as a whole, and remove the chain link (550) from the valve body (100) after the chain link (550) is loosened; S23, disconnecting the first injection hole (111) from the external pressure source, and opening the first injection hole (111) to release the pressure in the first pressure chamber (541); S24, connect the second injection hole (112) to the external pressure source, start the external pressure source to continuously pressurize so that the second pressure chamber (542) is filled with pressure medium; according to the formula V2 = L2 × π × (R3 2 -R4 2 ), Calculate the required medium pressure P2, where R3 is the outer ring radius of the second pressure chamber (542), R4 is the inner ring radius of the second pressure chamber (542), L2 is the stroke of the second pressure chamber (542), V2 is the volume of the second pressure chamber (542), and f2 is the friction force of the entire valve seat assembly (500); apply pressure until the pressure in the second pressure chamber (542) rises to ≥ P2, pushing the spring seat (530) to translate in a direction away from the ball (200), and continue to apply pressure until the spring seat (530) retreats to abut against the valve body (100) in the axial direction; S25, closing the first injection hole (111) to form a closed inner cavity of the first pressure chamber (541), then disconnecting the second injection hole (112) from the external pressure source and opening the second injection hole (112) to release the pressure of the second pressure chamber (542); S26, connect the third injection hole (113) to the external pressure source, start the external pressure source to continuously pressurize so that the third pressure chamber (543) is filled with pressure medium; according to the formula V3 = L3 × π × (R5 2 -R6 2 ), Calculate the required medium pressure P3, where R5 is the outer ring radius of the third pressure chamber (543), R6 is the inner ring radius of the third pressure chamber (543), L3 is the stroke of the third pressure chamber (543), V3 is the volume of the third pressure chamber (543), and f3 is the friction force of the entire valve seat assembly (500); apply pressure until the pressure in the third pressure chamber (543) rises to ≥ P3, pushing the valve seat (510) to move in a direction away from the ball (200), and continue to apply pressure until the valve seat (510) retreats to abut against the valve body (100) in the axial direction, and the valve seat assembly (500) and the ball (200) are completely separated and a gap of 10 to 30 mm exists; S27, disassembling the ball (200) and lifting it out of the cavity of the valve body (100); S28. Connect the first injection hole (111) to an external pressure source, start the external pressure source to continuously increase the pressure so that the pressure in the first pressure chamber (541) rises to ≥ P1, pushes the valve seat assembly (500) to move in the direction of the sphere (200) as a whole, and finally disassembles other parts that need to be repaired and hoisted out.

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