Rail valve

Abstract

Disclosed is a rail valve, comprising a valve body (1), a valve stem (7), a valve cover (6), a valve seat (12), a valve core (13), an actuation mechanism (9), and a rail beam (3); the rail beam (3) is an axisymmetric structure and is used for connecting the valve stem (7) with the valve core (13); the rail beam comprises a middle beam (3-1) and rails (3-2); an insertion hole is formed in the middle of the middle beam (3-1), and the E2 end of the valve stem (7) is vertically inserted within, where the insertion hole is internally provided with a space which only allows translation of the E2 end in the insertion hole in the direction across two rails; the two rails (3-2) are separately embedded in rail slots (16) that are correspondingly arranged on the valve core (13) on the outside of the two rails (3-2); the valve can be quickly opened and closed, the valve can replace blind valves, and the valve is widely applicable in many environments, such as oil and gas pipelines and fume extractor inlets and outlets in the petrochemical industry.

Description

Track valve Technical Field

[0001] The present invention relates to valves, and in particular to rail valves. Background Art

[0002] Track valves or track ball valves are widely used due to their frictionless opening and closing process, which not only effectively protects the sealing surface but also reduces the push-pull force or torque on the valve stem during opening and closing. However, existing track valves have many shortcomings, including: the closing force relies on the mechanical rotation of the angular plane at the bottom of the valve stem to wedge the valve disc tightly against the valve seat. The cantilevered end of the valve stem is easily damaged. In addition, the rotating wedge-type valve disc has a small contact area when the valve stem presses against the valve disc, which easily creates grooves on the valve disc, hindering the movement of the valve stem and affecting the closing of the track valve. When the medium pressure in the pipeline is extremely high, the clamping force required from the valve stem is extremely high, which is more likely to damage the valve stem and cause grooves. Such examples are common. For example, for a DN50 diameter orbital valve, the medium pressure is 15MPa, and the force required to compress the valve disc when closed is over 2945 kgf. Another example is a DN1100 diameter orbital valve, the medium pressure is 0.3MPa, and the force required to compress the valve disc when closed is over 28,495.5 kgf. This shows how large the force on the cantilever end of the valve stem is. For orbital valves of this size, the cantilever end of the valve stem is long, and the torque on the valve stem is large. In addition, high manufacturing precision is required for components such as the valve disc, valve seat, and trunnion, as well as high positional accuracy requirements between components, especially the coaxiality of the valve disc and valve seat: Precision directly affects various performance characteristics, including sealing performance, but high precision inevitably leads to high manufacturing costs and brings problems such as complex and difficult maintenance and debugging.

[0003] Various attempts have been made in the prior art to achieve this goal. For example, the "Emergency Cut-off Track Valve" disclosed in Chinese patent CN217736329U (published on November 4, 2022) achieves a large clamping force, but also presents some problems:

[0004] (1-1) The switching process requires two sets of actuators. If automatic control is to be achieved, two control systems are required, and misoperation must be prevented.

[0005] (1-2) The butterfly-shaped tightening block is used to expand and contract the elastic spherical component. Due to the limitation of the pressure angle, the cantilever part of the valve stem extending into the valve is longer. When the valve is closed, the valve stem is easily damaged due to the large radial torque it is subjected to.

[0006] (1-3) During the closing or opening process of the valve, if the cavity between the two sealing plates is filled with liquid medium, since the liquid is incompressible, the volume of the valve stem entering the valve body increases. This increased volume can only be absorbed by the axial deformation of the elastic spherical bracket and the sealing plate. This requires further increasing the push-pull force or torque output by the actuator, and causes the elastic spherical bracket to deform along the axial direction of the valve stem and the relative displacement between the sealing plate and the valve seat, thereby generating mechanical friction and damaging the sealing surface.

[0007] (1-4) The clamping force of the sealing plates on either side of the trunnion is less than that on either side of the valve stem, or the clamping force is uneven, affecting the actual performance of the valve. Furthermore, the sealing plates on either side of the trunnion are fixed to the valve stem via spherical brackets, increasing the constraints between the parts. This increases the requirements for positional accuracy between the related components, and requires the valve stem and trunnion to bend or shift radially to compensate. If the valve stem and trunnion are thick, compensation is difficult to achieve. Conversely, if the valve stem is thin, the stem is easily damaged, causing the valve to fail. The presence of trunnions and end caps makes the structure complex and expensive.

[0008] The prior art also discloses a track ball valve that utilizes a set of actuators to achieve the rotation of the valve disc, the displacement of the valve disc during the opening and closing process, and the compression between the valve disc and the valve seat. For example, Chinese patent CN205479439U (published on August 17, 2016) discloses a "new type of open track ball valve." However, in addition to the aforementioned problems (1-2), (1-3), and (1-4), it also has the following problems:

[0009] (2-1) The valve core moves up and down in the valve body to realize switching. If a set of actuators is used, the stroke of the valve stem cannot be small due to the limitation of the rotation pressure angle between the rotating track groove and the pin shaft. Accordingly, the up and down stroke of the valve core in the valve body is large. Due to the large size of the valve core, a large space is reserved above the interior of the valve body, and the upper valve stem and ear shaft are too long. High-pressure valves require the use of forgings, which will greatly increase the cost; and because the length of the valve stem in the valve body is long, the cantilever of the valve stem in the valve body is long. In this way, at the moment the valve is opened, the valve stem is easily damaged due to the large radial torque it is subjected to; if two sets of actuators are used in the switching process, the up and down stroke of the valve core in the valve is reduced, but if it is combined with automatic control, two control systems are required, which will cause the problems described in (1-1) above.

[0010] (2-2) The valve disc has no special or independent support and is supported by the sealing surface. Therefore, when the valve is opened, the valve stem rises and the valve disc moves toward the center line of the valve stem. The dead weight of the valve disc and the wedge-shaped cone will cause them to move down along the track. Then, when the valve is closed, it will be difficult for them to rise, making it difficult to close the valve. Secondly, during the entire opening and closing process of the valve, the valve disc is always in contact with the sealing surface, causing friction and wear and ultimately destroying its sealing performance. Even if limiting measures are taken to prevent the valve disc from sliding down or measures are taken to lift the valve disc through the wedge-shaped cone, friction and wear between the valve disc and the valve seat are inevitable, thereby affecting the sealing performance of the valve.

[0011] (2-3) The product has a complex structure and a large volume. For example, the valve core with a channel is equipped with a cone, a track and a valve disc connected to the cone, and the track and the valve disc are connected by bolts. For example, when used as a high-pressure valve, the force required to press the valve disc is very large. The valve core is only a part of the sphere. When pressing the valve disc, it is equivalent to using an arched part to press it. If the wall thickness of the valve core is thin, it is easy to become unstable. If the diameter of the valve core is kept unchanged, the wall thickness of the valve core needs to be very thick to meet the requirement, which will increase the size of the entire valve.

[0012] The above problems will undoubtedly affect the performance of the product (such as sealing performance), poor reliability, and increase manufacturing costs, usage costs and maintenance costs.

[0013] Furthermore, many gas pipelines use eyeglass valves as blind plates. Single-plate eyeglass valves leak during opening and closing, and require two sets of actuators, resulting in a complex structure. Double-plate eyeglass valves are even more complex, typically requiring two movable sealing chambers with multiple sealing surfaces. They also require four sets of actuators: two for opening and closing the sealing chambers, one for opening and closing the valve plate, and one for holding the valve plate in place. This leads to high manufacturing and maintenance costs, and they require additional space. Both types of eyeglass valves also require expansion joints. Furthermore, the mechanism for holding the valve plate in place is a hydraulic system, and in high-temperature environments, the effects of temperature on the hydraulic cylinder must be considered. Furthermore, concerns must be raised about condensation and scaling around the piston rod seal, which could affect piston rod movement.

[0014] In addition, many pipelines in the petrochemical and coal chemical industries, such as coal mill hot air pipelines, need to be installed with blind plates during maintenance, which undoubtedly increases the complexity of the maintenance work; especially when the medium temperature is high or the blind plate size is large, not only is on-site construction difficult, but there are also safety hazards. Summary of the Invention

[0015] In view of the various problems existing in the prior art, the present invention aims to provide a track valve, which can significantly reduce the radial force on the cantilever end of the valve stem when closing and compressing the valve disc; and reduce the requirements for position accuracy while ensuring sealing performance and reliability of use, thereby saving corresponding manufacturing and maintenance costs, and can be used to replace blind plate valves in many fields.

[0016] The technical solution of the present invention is achieved as follows:

[0017] A track valve includes a valve body, a valve stem (for the sake of clarity and brevity, the two ends of the valve stem are referred to as the E1 end and the E2 end respectively in the following text), a valve cover, a valve seat, a valve core, and an actuator for driving the valve stem to rise and fall. The valve core has two flaps, which are respectively located on both sides of the valve stem; in some cases, the valve core is also referred to as a valve flap. In the present invention, in some cases, such as to avoid difficulty in closing in liquid situations or difficulty in opening when the medium pressure is high and the valve size is large, the valve core on the downstream side of the medium is replaced by a bracket. The bracket can be understood as a valve core with a medium discharge port / hole. For example, it can be a through hole connected to the valve outlet on the basis of the structure of the valve core, or it can have other different structures from the valve core. When referring to the structure or related coordination of the valve core in the following text, unless otherwise specified or limited to the valve core on the upstream side of the medium, the relevant description or limitation of the valve core also applies to the bracket used to replace the valve core downstream of the medium; the valve stem passes through the valve The valve stem is provided with a track groove, the valve body is provided with a corresponding fixed guide pin, and the E1 end of the valve stem is connected to the actuator; the valve cover is arranged on the valve body and is detachably connected to the valve body, and the valve body is radially provided with an opening allowing the valve core to enter and exit, and the valve stem and the track groove and guide pin thereon are used in conjunction with the actuator to control the valve core to rotate and move toward the inlet and outlet directions of the valve to realize the opening and closing of the valve; the actuator may include a driving nut, and accordingly, the end of the valve stem close to the actuator is provided with a lead screw, and the rotation of the driving nut drives the valve stem to rise and fall; or the actuator may also be a hydraulic or pneumatic drive system.

[0018] The track valve also includes a track beam, which is used to connect the valve stem and the valve core, and the rise and fall and rotation of the valve stem drive the valve core to move and rotate to achieve the closing and opening of the track valve;

[0019] Specifically, the track beam is an axisymmetric structure, including a middle beam and tracks located on both sides of the middle beam;

[0020] The middle beam is provided with a socket in the center; the E2 end of the valve stem is vertically inserted into the socket;

[0021] The valve stem is provided with a limit structure at the upper and lower positions corresponding to the insertion hole, which is used to limit the relative displacement between the track beam and the valve stem along the valve stem's axial direction. Specifically, the limit structure can be a pin or a nut, or it can be a boss (the lower boss is similar to a chassis) provided at the upper and lower positions corresponding to the valve stem and the track beam (insertion hole), with the outer diameter of the boss being larger than the diameter of the insertion hole.

[0022] The valve body has a support surface on its inner wall opposite the end of the valve stem E2 for supporting the valve core. The support surface can be a plane or a conical surface; specifically, the plane is perpendicular to the axis of the valve stem, or the axis of the conical surface coincides with the axis of the valve stem.

[0023] Furthermore, considering the friction between the valve core and the supporting surface in the valve body, in order to minimize the rotational torque, the point on the supporting surface for supporting the valve core (referred to as the supporting point) is usually close to the axis of the valve stem.

[0024] The two rails are inclined downward toward the valve stem axis and fit into corresponding rail grooves on the valve core located outside them, with clearances matching the grooves. The clearances are sized to ensure that the rail grooves on the valve core do not interfere with the rails when the valve is closed. As previously mentioned, if a bracket is provided on the downstream side of the medium, the corresponding rail grooves that are clearance-matched with the rails on the track beam on that side are provided on the bracket.

[0025] The above structure is usually more suitable for soft sealing occasions, especially when the diameter is small, or the diameter is large and the pressure is low.

[0026] Furthermore, in order to reduce the requirements for manufacturing precision and / or reduce the radial force on the valve stem, the socket has space in only one dimension for the end of the valve stem E2 inserted therein to translate therein, and the dimension is along the direction spanning the two tracks;

[0027] In this way, the valve stem and the valve cores on both sides thereof are linked together by the track beam.

[0028] The track beam has a cross-sectional profile along the valve stem that is an isosceles trapezoid (specifically, the cross-sectional profile of the track beam along the valve stem between the two valve cores is an inverted trapezoid with a wider upper base and a narrower lower base, and the two isosceles correspond to the surfaces of the track that mate with the track grooves of the valve cores). Its cross-sectional profile perpendicular to the valve stem axis is a short "H" shape. Specifically, the intermediate beam corresponds to the middle crossbar of the short "H", and the insertion hole is a through hole that corresponds to a rectangular hole centered on the middle crossbar in the short "H" cross-section. Corresponding to the rectangular hole, the end portion of the valve stem B is configured as a square shaft segment with a cross-section that matches the rectangular hole. The only directional dimension in which the end portion of the valve stem B can move within the insertion hole corresponds to the dimension of the middle crossbar of the short "H". The two ends of the track extend out of the middle beam respectively, forming the two wings of the short "H"-shaped cross-section, that is, the two vertical bars of the short "H"; accordingly, the track grooves on the valve core located on both sides of the track beam are in a short "┣"-shaped or "┫"-shaped cross-section perpendicular to the axial direction of the valve stem, and the track and a small section of the middle beam connected to the track are embedded therein.

[0029] In order to ensure that the portion of the track beam that presses the valve core is located as close as possible to the center line of the valve core, the surface of the track that matches the track groove on the valve core is set to be higher in the middle and lower at both ends.

[0030] The middle raised portion of the track usually corresponds to the center line of the valve core and can be set to a circular or square plane to press the valve core, which is called the pressing portion of the track.

[0031] In order to prevent the sealing portion above the valve core from contacting the corresponding portion of the valve seat first due to the medium pressure when the valve is closed, the center of the pressing portion of the track can be set to be slightly below the center line of the valve core, for example, at a position directly below it.

[0032] Furthermore, the track valve may also include a cantilever lever, which is a thin elastic rod having a fixed end and a cantilever end. The fixed end is connected to the underside of the track of the track beam, and the cantilever end is spaced apart to fit within the track groove of the valve core. The size of the gap is such that the track groove on the valve core and the cantilever lever do not interfere with each other when the valve is closed.

[0033] Typically, the cantilever rods can be installed one on each side below the two rails, or one each near the two ends below each rail.

[0034] The cantilever lever is designed to ensure the valve core is in the ideal position before the valve body is closed. The influence of the cantilever lever on the corresponding rail pressing the valve core must also be considered. Therefore, the elasticity of the cantilever lever is also determined by the weight and center of gravity of the valve core: before the valve core is pressed, the deformation of the cantilever lever is minimal, thereby ensuring that there is no significant positional error between the valve core and the valve seat. After the valve core is pressed, if the cantilever lever presses the valve core before the rail, due to its certain elasticity, the cantilever lever will elastically deform with further compression, allowing the rail to press the valve core almost at the center, thereby reducing the positional accuracy requirement between the valve core and the valve seat. It has been proven that this positional accuracy is difficult to achieve under normal circumstances for existing rail valves, and accordingly imposes higher requirements on manufacturing and maintenance. The present invention relies on the cantilever lever structure and its elastic characteristics to allow the valve core to rotate to a certain angle in the closed position of the valve body, reducing the corresponding constraints and, in turn, reducing the corresponding positional accuracy requirements.

[0035] When a structure is selected in which two cantilever rods are fixed under each track, the two cantilever rods under each track are arranged in parallel and spaced a certain distance apart. This will give the corresponding valve core more freedom of rotation, thereby reducing the corresponding constraints and lowering the requirements for the corresponding position accuracy. On the one hand, it ensures the performance of use, and on the other hand, it is conducive to reducing the corresponding production and manufacturing costs and use and maintenance costs.

[0036] For installation purposes, a notch is usually provided on the valve core on a side close to the actuator for the track beam and the limiting member to enter and exit.

[0037] Taking into account that the hard particles in the medium may affect the sealing performance after eroding the valve seat, the sealing surface of the valve seat faces the low-pressure end of the pipeline.

[0038] When the valve is fully open, there is a gap between the valve core and the valve seat and the inner wall of the valve body. The medium causes erosion and wear on the outer side of the valve core, the valve seat, the sealing ring or sealing packing on the valve seat, and the inner wall of the valve body. To this end, the valve core of the present invention can be arranged eccentrically relative to the valve stem (similar to the eccentricity of the valve stem and valve plate in an eccentric butterfly valve). Specifically:

[0039] The center lines L1 and L2 of the two valve cores are respectively on both sides of the axis of the valve stem, and the distances therebetween are ΔL1 and ΔL2 respectively;

[0040] When the track valve is in the fully open state, plane M1 and plane M1' are not perpendicular to the axis L of the medium inlet and outlet on the valve body; wherein, M1 is the plane where the edges of the sealing surfaces of the two valve cores corresponding to the upstream side of the medium are located, close to the center of the valve body, when the track valve is fully open; M1' is the plane where the edges of the sealing surfaces of the two valve cores corresponding to the downstream side of the medium are located, close to the center of the valve body, when the track valve is fully open.

[0041] When the track valve is in its fully closed state, plane N1 and plane N1' are not perpendicular to the axis L of the medium inlet and outlet on the valve body; wherein, N1 is the plane where the edge of the sealing surface of the valve core located on the upstream side of the medium, close to the center of the valve body, is located when the track valve is fully closed; N1' is the plane where the edge of the sealing surface of the valve core located on the downstream side of the medium, close to the center of the valve body, is located when the track valve is fully closed.

[0042] Furthermore, the two valve cores are symmetrical with respect to the center of the valve body. At this time, ΔL1 and ΔL2 are equal in size, and when the track valve is in its fully open and fully closed states, planes M1||M1' and N1||N1'.

[0043] The track valve of the present invention can be used to replace the blind plate valve in the pipeline, including but not limited to the following typical applications:

[0044] Application 1: When it is used for gaseous media, the valve stem of the track valve adopts two identical valve cores on both sides, and an inlet and an outlet for displacement or discharge are respectively opened on both sides of the inlet and outlet axes of the valve body, perpendicular to the inlet and outlet axes of the valve body. Conventional valves are respectively installed on the inlet and outlet for displacement or discharge. Opening the conventional valves can realize the function of a blind plate.

[0045] Application 2: When used to replace the blind plate in the pipeline, in order to achieve a partition that meets the safety of the human body, and considering that hard particles in the medium may affect the sealing performance after eroding the sealing surface on the bracket side, or the problem that the valve is difficult to open and close when used for liquid media, the present invention can adopt the following combined application form: two track valves described in the present invention are installed adjacent to each other on the corresponding pipeline. The track valves all adopt a valve core and a bracket structure. On both sides of the pipeline between the two track valves, a conventional valve is installed along the radial direction of the pipeline. When the two track valves are closed, the two conventional valves are opened, and the pipeline between the track valves of the present invention is connected to the atmosphere, so that a partition that meets the safety of the human body can be achieved. At this time, there is no need to worry about the problem of the medium in the pipeline flowing downstream after the upstream valve seat is worn.

[0046] When used as a blind plate, close the track valve and detect whether there is leakage between the two valve cores of the track valve (such as in application 1) or in the pipeline between the two track valves. Alternatively, after closing the valve, replace the medium in the pipeline downstream of the valve, wait for a period of time, and then take samples for analysis or use instruments to detect whether there is any leakage.

[0047] Furthermore, as in Application 1, when the conventional valves on both sides of the valve body are opened, if the track valves are not sealed tightly, in order to prevent the leaked high-temperature flammable medium from catching fire, the outlets of the conventional valves on both sides of the valve body can be installed with fire caps;

[0048] In order to prevent the oil and gas leaking out from catching fire when the seal is not tight in oil and gas occasions, a heat exchanger for reducing the oil and gas temperature is installed between the conventional valves on both sides of the valve body and the fire cap.

[0049] Specifically, the following settings can be made separately or simultaneously based on the specific situation:

[0050] For large-sized valves, the valve core is usually heavier, and the friction between the valve core and the inner wall of the valve body is relatively large. A universal bearing can be installed between the valve core and the corresponding supporting surface in the valve body. For example, a universal bearing can be installed below the valve core, and the ball of the universal bearing is located near the center of the supporting surface.

[0051] Furthermore, a circular groove may be provided at the center of the support surface on the valve body, wherein the circular groove is coaxial with and perpendicular to the valve stem; and the universal bearing may be located in the circular groove.

[0052] Furthermore, in order to prevent the fluid medium from causing the valve core to vibrate after the valve is opened, after the valve is fully opened, the valve stem is clamped by the valve cores on both sides thereof.

[0053] To prevent the valve core from moving upward during opening due to its light weight, the valve cover is provided with an annular step or annular surface on its inner wall near the actuator, which fits over the valve stem. The annular step or annular surface is perpendicular to the axis of the valve stem, thereby limiting the upward movement of the valve core.

[0054] Alternatively, in order to prevent the fluid medium from causing the valve core to vibrate after the valve is opened, the notch of the valve core is respectively provided with notches perpendicular to the valve stem, on which a long plate is fixed, and the upper and lower surfaces of the long plate are both perpendicular to the axis of the valve stem. After the valve is fully opened, the long plate is clamped between the track beam and the annular step or annular plane.

[0055] Alternatively, in order to more reliably prevent the fluid medium from causing the valve core to vibrate after the valve is opened, and to ensure that the valve core is clamped, two disc springs are symmetrically fixed on the annular step or annular plane on the valve cover relative to the valve stem.

[0056] The track groove on the valve stem includes two sections, including: 1. a straight groove section I of the track groove, which is parallel to the axis of the valve stem and close to one end of the valve body, corresponding to the translational movement of the valve core and the valve stem away from or approaching each other; 2. a spiral groove section II of the track groove, which connects to the upper end of the straight groove section I, spirally rises and falls along the axial direction of the valve stem, and is close to one end of the actuator, corresponding to the rotation movement of the valve core or also includes the movement of the valve core pressing or loosening the valve seat.

[0057] For the non-eccentric track valve described in the present invention, in order to avoid the aforementioned vibration problem and more reliably clamp the valve core, the track groove on its valve stem may include three sections: 1. a straight groove section I of the track groove, which is parallel to the axis of the valve stem and close to one end of the valve body, corresponding to the translational movement of the valve core and the valve stem away from or approaching each other; 2. a straight groove section III of the track groove, which is parallel to the axis of the valve stem and close to one end of the actuator, corresponding to the movement of the valve core pressing or loosening the valve seat; 3. a spiral groove section II of the track groove, which is centered to connect the two straight groove sections I and III and spirally rise and fall along the axial direction of the valve stem, corresponding to the rotation and translational movement of the valve core.

[0058] Furthermore, the track beam can be constructed as an arched beam, that is, the lower base (short side of the trapezoid) of its inverted trapezoidal cross section is an arc-shaped curved side of the upper arch; the diameter of the arc on the arched beam is not less than the inner diameter of the valve core.

[0059] In order to further improve the sealing performance, an annular groove is opened on the sealing surface of the valve seat, and a sealing ring or sealing filler is embedded in the groove.

[0060] Taking into account that when there is an insulation lining in the pipeline, the valve body and the valve seat fixedly connected thereto expand at different rates, the valve seat may yield, deform, creep, etc., resulting in problems such as poor sealing after the valve seat is deformed and damage to the lining. A floating valve seat structure can be formed, that is, the valve seat is allowed to expand freely in the radial direction in addition to the friction constraint of clamping. For details, please refer to the patent application previously submitted by the inventor with publication number CN109027264A, entitled "A Valve and Its Application", which is now incorporated into the present application by reference.

[0061] Typically, when there's a thermal lining inside a pipeline, the medium's temperature is high, causing the valve core or bracket to expand due to the heat. This causes the centerline of the valve core and bracket to move upward, while the centerline of the valve seat remains unchanged. To mitigate damage to the valve, especially the sealing surfaces, it's often considered to allow the bottom of the valve core to contact the valve seat first. Therefore, a design is employed where the centerline of the valve core is lower than the centerline of the valve seat. For a regularly symmetrical valve core and seat, the centerline of the valve core and the centerline of the valve seat are their corresponding central axes.

[0062] Furthermore, the design data of the above-mentioned dimensions can be obtained according to the material and through corresponding calculations, such as based on the size and material expansion coefficient, to ensure that the center line of the valve core is lower than the center line of the valve seat after thermal expansion, thereby obtaining the corresponding technical effect; or, it is also possible to find a matching material according to the corresponding dimensional requirements.

[0063] Compared with the prior art, the present invention has the following advantages:

[0064] 1. It can realize fast switching, so it can be used as a quick shut-off valve.

[0065] Taking the DN1200 valve as an example, the structure of the track valve of the present invention is adopted, the valve core is set at the upstream of the medium, and the bracket is set at the downstream. Assuming the pressure of the medium is 0.2MPa (about 2kgf / cm 2), during its switching process, the displacement of the valve core and the bracket in the direction perpendicular to the valve stem is 4mm, the stroke of the valve stem is 600mm, assuming that the total weight of the valve core and the bracket is 1000kgf, the steel-to-steel friction coefficient is 0.15, during the rotation of the valve core, the distance between the valve core and the bracket and the valve stem axis is 1mm respectively, and the track is 610mm away from the valve stem axis. Considering the friction and rotational torque between each component and the clamping force required to close the valve core, and considering the friction and friction distance between the packing and the valve stem, theoretical calculations show that: the switching process of the track valve of the present invention requires a push-pull force of the valve stem greater than 400kgf to meet the use requirements. For example, using a DN150mm cylinder, the air pressure is 0.5MPa, and the thrust of the piston is 883kgf.

[0066] Since the torque or push-pull force of the required actuator is small, rapid switching can be achieved, so the track valve of the present invention can be used as a rapid shut-off valve.

[0067] Calculation and deduction show that during the switching process of the track valve described in the present invention, the radial force on the valve stem is small and the corresponding cantilever torque is small. This improves the reliability of the valve stem on the one hand, and at the same time allows for smaller sizes and simplified structures of corresponding parts such as the valve stem. For example, even without a trunnion and a trunnion hole, the torque during rotation of the valve core / bracket is also very small, and the force required to move the valve core / bracket is also small, which reduces the requirements for the push-pull force or torque output of the actuator, and correspondingly reduces manufacturing and maintenance costs.

[0068] In particular, the socket on the track beam has space that allows the end of the valve stem E2 to translate in a direction across the two tracks. This significantly reduces the radial force and corresponding cantilever torque directly borne by the valve stem, which is of great significance for track valves with slightly larger diameters and higher operating pressures. When the valve is opened, the valve stem drives the track beam upward until the upstream valve core is a certain distance away from the valve seat. Under the action of the medium pressure, the valve core leaves the valve seat and pushes the track beam downstream, gradually increasing the distance between it and the valve seat. The bracket located downstream is subjected to the medium pressure and the thrust of the beam and abuts the corresponding valve seat, while the valve stem is basically not subjected to radial force. Since the bracket is provided with a through hole, the medium flows downstream through this through hole, thereby significantly reducing the pressure difference on both sides of the valve core, thereby avoiding or reducing the radial force exerted by the valve core on the valve stem. When the valve stem and the track beam rise further, the bracket gradually separates from the valve seat, and the valve stem then drives the track beam to rotate (for example, counterclockwise) 90 。 , the valve is fully open. On the contrary, when the valve is closed, the valve stem first drives the track beam to rotate 90 degrees in the opposite direction (for example, clockwise). 。 , and then moves downward until the valve core is finally tightened, the valve is completely closed and the medium is intercepted.

[0069] 2. Under the premise of ensuring sealing and reliability, the constraints are reduced and the degree of freedom is increased. Accordingly, the position accuracy requirements are reduced and the process performance is improved.

[0070] In the present invention, there are many designs based on this consideration. For example, the present invention does not use an ear shaft, but instead provides a support surface at the corresponding position of the valve body to support the valve core; for another example, on the aforementioned track beam, there is space in the socket for the end of the valve stem E2 to move horizontally only along the direction across the two tracks; for another example, during the normal valve closing process, if the upper part of the valve core contacts the valve seat first, this contact point will form a rotation radius with the support point of the valve core on the inner wall of the valve, which is larger than the rotation radius of the lower part of the valve core that continues to approach the valve seat, causing interference problems; the cantilever rod of the present invention is configured as a slender elastic element, which is fixed under the track beam, allowing the valve core to rotate a certain angle in multiple dimensions, ensuring that the valve core is in close contact with the valve seat everywhere when the valve is closed, and also ensuring that the part that presses the valve core is basically located in the middle of the valve core, naturally overcoming the above-mentioned interference problem; in addition, the cantilever rod also effectively meets and realizes the performance requirements including sealing and reliability.

[0071] 3. Structural Optimization. The valve core / bracket structure of the present invention is simpler, integrating a track groove that mates with the track beam. This not only eliminates the need for fasteners such as bolts, but also increases the contact or mating area, making it less susceptible to indentation and jamming, thereby improving reliability. Furthermore, the narrow overall width of the track beam allows for efficient space utilization within the valve body, facilitating a longer valve stem stroke and minimizing the valve's size.

[0072] 4. There are no structures such as trunnions and trunnion holes, which accordingly avoids the problem of valve opening and closing being stuck due to the accumulation of impurities.

[0073] 5. The eccentric structure design can not only ensure the good flow state of the medium in the valve, but also effectively avoid the erosion and wear of the medium on the outside of the valve core / bracket, the valve seat and the sealing structure on the valve seat, thereby ensuring the long-lasting good sealing performance of the sealing surface and greatly improving the service life and reliability of the valve.

[0074] The above structural optimization without exception guarantees and improves the sealing and reliability of the present invention, while naturally achieving the effect of energy saving and consumption reduction, effectively reducing the cost of various links including manufacturing, use and maintenance, and especially simplifying the debugging process during maintenance.

[0075] When the inlet and outlet of the valve seat are both set to a sealed state, the present invention can replace the blind plate valve and is widely used in many occasions including the inlet and outlet pipes of hydrogen, liquefied gas, LNG, oil and gas pipelines and smoke exhaust fans in the petrochemical industry; compared with the glasses valve used as a blind plate, the present invention does not require an expansion joint, has a more optimized structure, occupies less space, and is particularly reliable and cost-effective; in particular, it solves the problem of high-torque valves being difficult to achieve rapid switching, which has long plagued the field, and solves the problem of large-diameter track valves being unable to be used due to the large cantilever torque acting on their valve stems. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] FIG1 is a schematic structural diagram of a track valve 100 according to Embodiment 1 of the present invention;

[0077] FIG2 is a cross-sectional view taken along line AA of FIG1 ;

[0078] FIG3 is a schematic structural diagram of a track valve 200 according to Embodiment 2 of the present invention;

[0079] FIG4 is a schematic diagram of a track valve 200 described in Example 2 of the present invention being used in place of a blind plate valve;

[0080] FIG5 is a schematic diagram of a three-dimensional structure of two track valves 100 used as blind plates according to Example 4 of the present invention;

[0081] FIG6 is a schematic structural diagram of a track valve 100 in which a circular groove is provided on the inner wall of the valve body facing the axis of the valve stem;

[0082] FIG7 is a schematic diagram of the eccentric structure of the valve core / support of the track valve 300 described in Example 5 of the present invention when it is in a fully closed state;

[0083] FIG8 is a schematic diagram of the eccentric structure of the valve core / support of the track valve 300 described in Example 5 of the present invention when it is fully opened.

[0084] 1. Valve body 2. Bracket 2-1. Through hole 3. Track beam 3-1. Intermediate beam 3-2. Track 4. Stopper 5. Long strip 6. Valve cover 7. Valve stem 8. Support 9. Actuator 10. Drive nut 11. Guide pin 12, 12'. Valve seat 13, 13'. Valve core 14. Cantilever rod 15. Stopper 16. Track groove on valve core or bracket 17. Seal ring or sealing packing 18, 18'. Universal bearing 19, 19'. Conventional valve 20. Pipeline 21. Support surface 21-1. Circular groove

[0085] EFG is the track groove on the valve stem, where

[0086] Section G. Straight track section I;

[0087] Section F. Spiral groove section II of the track groove;

[0088] Section E. Straight track section III.

[0089] L. Axis of the medium inlet and outlet on the valve body

[0090] L1. Centerline of valve core or bracket on downstream side of medium

[0091] L2. Centerline of the valve core on the upstream side of the medium

[0092] ΔL1, ΔL2. The distances from L1, L2 to L respectively

[0093] M 1。 When the valve is fully open, the plane where the sealing line (points C and D are on the sealing line) of the sealing surface of the two valve cores (or a valve core and a bracket) on the upstream side of the medium close to the center of the valve body is located;

[0094] M1'. The plane where the sealing line (points C' and D' are on the sealing line) of the sealing surfaces of the two valve cores (or one valve core and one bracket) on the downstream side of the medium and close to the center of the valve body is located when the valve is fully open;

[0095] N1. When the valve is fully closed, the plane where the sealing line of the valve core's sealing surface on the upstream side of the medium and close to the center of the valve body (points A and B are on the sealing line) is located;

[0096] N1'. When the valve is fully closed, the plane where the sealing line of the sealing surface of the valve core (or bracket) located on the downstream side of the medium and close to the center of the valve body (points A' and B' are on the sealing line) is located. DETAILED DESCRIPTION

[0097] The present invention will now be further described in detail with reference to the accompanying drawings. Example

[0098] A track valve, as shown in Figures 1 and 2, includes a valve body 1, valve seats 12 and 12', a valve core 13 located on the upstream side of the medium, and a bracket 2 located on the downstream side of the medium (in order to avoid difficulty in closing in liquid applications or difficulty in opening when the medium pressure is high and the valve size is large, the valve adopts a bracket 2 on the downstream side of the medium, which is provided with a through hole 2-1 communicating with the valve outlet; the arrow in the figure represents the flow direction of the medium), a track beam 3, a valve stem 7, a valve cover 6, an actuator 9, and a drive screw nut 10; the valve stem 7 has a screw thread at one end near the actuator 9. The valve stem is provided with a track groove EFG, and a corresponding guide pin 11 is fixed on the valve body. The valve cover 6 is mounted on the valve body 1 and is detachably connected to the valve body 1. The valve body 1 is provided with a radial opening to allow the valve core 13 and the bracket 2 to enter and exit. The actuator 9 is connected to the E1 end of the valve stem 7. The valve stem, the track groove EFG, and the guide pin 11 thereon drive and control the rotation of the valve core 13 and the bracket 2, as well as their movement away from or toward the valve inlet and outlet, to open and close the valve. The actuator 9 can also be a hydraulic or pneumatic system. The hydraulic or pneumatic system is preferably linear, with a hydraulic rod or piston rod driving the valve stem up and down to open and close the valve. In this case, the valve stem can be without a lead screw segment, and the nut can be removed.

[0099] The track beam 3 is an axisymmetric structure, comprising a center beam 3-1 and tracks 3-2 located on either side of the center beam. A socket is provided in the center of the center beam 3-1. End E2 of the valve stem 7 is inserted vertically into the socket. The socket has space within one dimension only, allowing translation of the inserted end E2 of the valve stem. The dimension is transverse to the two tracks 3-2, as shown in FIG2 . The two tracks 3-2 are inclined from top to bottom toward the axis of the valve stem 7 and are respectively embedded in corresponding track grooves 16 on the valve core 13 and the bracket 2 located outside of the two tracks, with a clearance fit between the track grooves 16. The clearance size is such that when the valve is closed, the track grooves on the valve core and the bracket do not interfere with the track.

[0100] The cross-sectional profile of the track beam 3 along the axial direction of the valve stem 7 is an isosceles trapezoid, as shown in FIG1 ; the cross-sectional profile of the track beam 3 perpendicular to the axial direction of the valve stem 7 is a short "H" shape, as shown in FIG2 . The insertion hole is a through hole, which corresponds to a central rectangular hole on the short "H" cross section; the two tracks 3-2 constitute the two wings of the short "H" cross section;

[0101] Corresponding to the rectangular socket of the middle beam 3-1, the end E2 of the valve stem 7 is configured as a square shaft segment having a cross section matching the rectangular socket;

[0102] The track grooves on the valve core and the bracket are short "┣"-shaped or "┫"-shaped in a cross section perpendicular to the axial direction of the valve stem, and the track and a small section of the middle beam connected thereto are embedded therein, as shown in Figures 1 and 2.

[0103] In order to ensure that the portion of the track 3-2 that presses the valve core 13 / bracket 2 is located as close as possible to the center line of the valve core 13 / bracket 2, the surface of the track that matches the track groove 16 on the valve core 13 / bracket 2 is set to be higher in the middle and lower at both ends; and the higher middle portion of the track 3-2 usually corresponds to the vicinity of the center line of the valve core 13 / bracket 2, and is usually set to a circular or square plane to press the valve core 13 / bracket 2, which is called the pressing portion of the track (not shown in the figure).

[0104] Furthermore, in order to prevent the sealing portion above the valve core 13 from contacting the corresponding portion of the valve seat first due to the medium pressure when the valve 100 is closed, the center of the pressing portion of the track is set at a position slightly below the center line of the valve core 13.

[0105] The track valve is also provided with a cantilever rod 14, which is a thin elastic rod with a fixed end and a cantilever end. The fixed end is connected to the bottom of the track 3-2, and the cantilever end is clearance-matched with the track grooves on the valve core 13 and the bracket 2. The size of the clearance is required to ensure that the track grooves on the valve and bracket do not interfere with the cantilever rod when the valve is closed.

[0106] The valve stem 7 is provided with limit members 4 and 15 at the upper and lower positions corresponding to the insertion hole, respectively. The limit members 4 and 15 may be pins, nuts, etc., or may be structures such as bosses or steps with an outer diameter larger than the outer diameter of the valve stem 7 to limit the axial displacement of the track beam 3 along the valve stem 7.

[0107] The inner wall of the valve body 1 is provided with a supporting surface 21 at a position opposite to the E2 end of the valve stem 7, for supporting the valve core 13 and the bracket 2; specifically, as shown in Figures 1, 3, and 6, the supporting surface 21 can be a plane or a conical surface; the plane is substantially perpendicular to the axis of the valve stem, or the axis of the conical surface substantially coincides with the axis of the valve stem.

[0108] In order to reduce the impact of hard particles in the medium on the valve seat and its sealing performance, the sealing surface of the valve seat faces the low-pressure end of the pipeline.

[0109] Furthermore, the lower bottom of the track beam 3 (i.e., the short bottom side corresponding to the trapezoidal cross-section) can be set to an upward arc shape, so that the track beam is in the form of an arched beam; specifically, the arc diameter of the arched beam is greater than or equal to the inner diameter of the valve core 13, so that the up and down stroke of the valve stem 7 can be reduced.

[0110] In order to further improve the sealing performance, annular grooves are formed on the sealing surfaces of the valve seats 12 and 12 ′, and sealing rings or sealing fillers 17 are embedded therein.

[0111] Taking into account that the lower part of the valve core 13 and the bracket 2 is first in contact with the valve seats 12, 12', or when there is a thermal insulation lining in the pipeline, the temperature of the medium is usually higher, and the valve core 13 / bracket 2 expands after being heated, and its center line moves up, while the center line of the valve seats 12, 12' remains unchanged. In this case, the center line of the valve core 13 or the bracket 2 is set to be lower than the center line of the valve seats 12, 12', which can be calculated through thermal expansion and contraction.

[0112] Combined with the characteristics of the track groove EFG on the valve stem, the opening process of the track valve 100 can be described in the following two to three stages:

[0113] In stage I, the valve stem guide pin 11 is located in section G of the track groove, i.e., in the straight groove section I. Under the limiting action of the guide pin 11, the valve stem 7 drives the track beam 3 to rise linearly. The arrow represents the flow direction of the medium. As shown in FIG1 , there is a certain distance between the surfaces of the valve stem E2 ends facing the upstream valve core 13 and the downstream bracket 2 and the corresponding inner surfaces of the socket on the track beam (constituting a translation space). In the initial stage of opening the valve 100, under the action of the medium pressure, the bracket 2 is pressed against the corresponding valve seat 12 ', and the valve core 13 Move toward the valve stem 7. At this time, the valve stem 7 is almost not subjected to radial force. As the valve stem 7 continues to rise, the surface of the valve stem E2 end facing the valve core 13 is in contact with the corresponding surface of the insertion hole of the middle beam 3-1 of the track beam. At this time, the opening of the valve 100 is already large. The medium entering the valve body 1 flows downstream through the through hole 2-1 on the bracket 2. The pressure difference between the valve core 13 and the bracket 2 is greatly reduced. As the valve stem 7 further rises, the bracket 2 leaves the valve seat 12' and moves toward the valve stem 7. During this process, the radial force on the valve stem 7 is not too large.

[0114] Entering stage II, as the actuator 9 continues to operate, the guide pin 11 enters the track groove section F, that is, the spiral groove section II. Under the limiting action of the guide pin 11, the valve stem 7 rotates while rising, and the valve core 13 and the bracket 2 perform a compound motion of rotation and displacement toward the valve stem 7. The tracks 3-2 on both sides of the track beam or their circular or square pressing parts are separated from the pressing points on the valve core 13 and the bracket 2. At this time, the valve 100 is fully opened; in order to prevent the fluid medium from causing the valve core 13 and the bracket 2 to vibrate after the valve 100 is opened, after the valve 100 is fully opened, the track 3-2 acts on the valve core 13 and the bracket 2 to exert a component force toward the valve stem 7, so that the valve core 13 and the bracket 2 clamp the valve stem 7.

[0115] Alternatively, when the track groove on the valve stem 7 also includes section E, i.e., straight groove section III, the valve 100 continues to enter stage III after it is fully opened. During this stage, the guide pin 11 continues to enter straight groove section III, which is connected to the spiral groove section II and is also a straight groove parallel to the axis of the valve stem 7. Under the restraining action of the guide pin 11, the valve stem 7 continues to move upward until the valve core 13 and the long strip 5 on the bracket 2 are clamped between the annular step or annular surface (not shown) provided on the track beam 3 and the valve cover 6. At this point, the track beam 3 also fully enters the corresponding notch between the valve core 13 and the bracket 2. Alternatively, in this straight groove section III, the valve stem 7 can be clamped between the valve core 13 and the bracket 2 by the component force exerted by the track 3-2 on the valve core 13 and the bracket 2, thereby clamping the valve stem 7.

[0116] The closing process of the track valve 100 and its opening process are completely symmetrical and reverse processes, so they will not be described in detail here. Example

[0117] The track valve 200 is used for gaseous media, as shown in FIG3 . It differs from the embodiment 1 mainly in that it uses the same valve core 13 ′ on the downstream side of the medium as on the upstream side of the medium, but does not use the bracket 2 with the through hole 2 - 1 .

[0118] For large-sized valves, the valve core 13 is heavy, and the friction between it and the inner wall of the valve body 1 is also large. Therefore, universal bearings 18 and 18' can be installed between the support surface 21 and the valve cores 13 and 13', respectively. That is, universal bearings 18 and 18' are installed below the valve cores 13 and 13', respectively, and the balls on the universal bearings 18 and 18' sit on the support surface 21. The arrangement of the universal bearings is also applicable to the case where the downstream side of the medium in the track valve 100 of Example 1 is the bracket 2, as shown in Figure 6.

[0119] Furthermore, a circular groove 21-1 can be provided on the support surface 21, as shown in FIG6 , the plane inside the circular groove 21-1 is perpendicular to the axis of the valve stem 7 and coaxial with the valve stem 7, and the balls 18 and 18' of the universal bearing supporting the valve core 13 and the bracket 2 are located in the circular groove 21-1; similarly, the setting of the circular groove 21-1 is also applicable to the case where the downstream side of the medium is also a valve core track valve 200 as shown in FIG3 . Example

[0120] FIG4 shows a case where the track valve 200 is used to replace a blind plate valve in a pipeline. When used for gaseous media, the valve stem 7 of the track valve 200 has two identical valve cores 13, 13' (not shown). Inlet and outlet valves for displacement or discharge are provided on both sides of the inlet and outlet axes of the valve body 1, perpendicular to the inlet and outlet axes of the valve body 1. Conventional valves 19, 19' are also provided. When used as a blind plate, the track valve 200 is closed and the conventional valves 19, 19' are opened to detect leakage in the pipeline between the two valve cores of the track valve 200. Alternatively, after closing the track valve 200, the medium in the downstream pipeline may be displaced. After a period of time, sampling and analysis or instrumentation may be performed to confirm leakage. Example

[0121] As shown in FIG5 , the track valve 100 is used to replace a blind flange valve in a pipeline. To achieve a safe isolation barrier, and considering the impact of hard particles in the medium on the sealing surface of the bracket 2, which may affect the sealing performance of the valve 100, and / or the common problem of valve difficulty in opening and closing when used with liquid media, the track valve 100 combination described in Example 1 can be used to replace the blind flange valve in the pipeline. Specifically, two track valves 100 are installed adjacent to each other on the corresponding pipeline, and a conventional valve 19, 19' is installed on both sides of the pipeline 20 between them along its radial direction (i.e., the axis of the conventional valve is perpendicular to the axis of the pipeline). After closing the two track valves 100, the two conventional valves 19, 19' are opened, and the pipeline 20 is connected to the atmosphere, thus achieving a safe isolation barrier. At the same time, the problem of the medium in the pipeline flowing downstream due to wear of the valve seat 12' on the downstream side of the medium can be avoided. Example

[0122] When the valve is fully opened, due to the gap between the valve core / bracket and the valve seat and the inner wall of the valve body, the medium will cause erosion and wear on the outer side of the valve core / bracket, the valve seat, the sealing structure on the valve seat (including sealing strips or sealing packing, etc.), and even the inner wall of the valve body. In order to eliminate or reduce this wear and its impact on the reliability and service life of the valve, the track valve 300 is provided with an eccentric valve core / bracket, as shown in Figures 7 and 8. Specifically:

[0123] The center lines L1 and L2 of the bracket 2 and the valve core 13 are respectively arranged on both sides of the axis of the valve stem 7, and the distances therebetween are ΔL1 and ΔL2 respectively (the valve stem 7 is located at the center of the valve body, so the axis of the valve stem 7 falls on the axis of the medium inlet and outlet on the valve body), and the bracket 2 and the valve core 13 are centrally symmetrical with respect to the valve body 1, ΔL1 and ΔL2 are equal in size, and when the track valve 300 is in its fully open and fully closed states, planes M1|M1' and N1|N1 are shown in Figures 7 and 8; wherein,

[0124] M1 is the plane where the edge sealing line of the sealing surface on the valve core 13 and the bracket 2 corresponding to the upstream side of the medium is located, close to the center of the valve body when the track valve 300 is fully opened. M1' is the plane where the edge sealing line of the sealing surface on the valve core 13 and the bracket 2 corresponding to the downstream side of the medium is located, close to the center of the valve body when the track valve 300 is fully opened.

[0125] Correspondingly, N1 is the plane where the edge sealing line of the sealing surface on the upstream side of the valve core 13 close to the center of the valve body is located when the track valve 300 is fully closed, and N1' is the plane where the edge sealing line of the sealing surface on the downstream side bracket 2 close to the center of the valve body is located when the track valve 300 is fully closed.

[0126] When the track valve 300 is in its fully open state, planes M1 and M1' are not perpendicular to the axis L of the medium inlet and outlet on the valve body; similarly, when the track valve 300 is in its fully closed state, planes N1 and N1' are not perpendicular to the axis L of the medium inlet and outlet on the valve body.

[0127] The sealing surfaces of the track valve 300 in the fully open state and the fully closed state are further described in detail as follows:

[0128] After the track valve 300 is fully opened, as shown in Figure 8, the sealing surfaces on the valve core 13 and the bracket 2 include the arcuate or spherical portions at one end of the valve core 13 and the bracket 2, which are located at the upstream position of the medium at this time, and respectively cooperate and seal with the valve seat 12 located at the upstream position of the medium, that is, the arcuate or spherical portions corresponding to points C and D in the figure (i.e., away from the center direction of the valve body); the sealing surface also includes the arcuate or spherical portions at the other end of the valve core 13 and the bracket 2, which are located at the downstream position of the medium at this time, and respectively cooperate and seal with the valve seat 12' located at the downstream position of the medium, that is, the arcuate or spherical portions outside points C' and D' in the figure (i.e., away from the center direction of the valve body).

[0129] When the track valve 300 is fully closed, as shown in FIG7 , the sealing surface generally only includes the sealing surface on the valve core 13 located upstream of the medium, that is, the arcuate or spherical portion of the valve core outside points A and B (i.e., away from the center of the valve body); when the track valve is used as a blind plate valve, the bracket on the downstream side of the medium needs to be replaced with the valve core 13 ' and participate in the sealing. In this case, the sealing surface also needs to include the sealing surface on the valve core 13 'on the downstream side of the medium, that is, the arcuate or spherical portion of the bracket outside points A' and B' (i.e., away from the center of the valve body) as shown in the figure.

[0130] The opening process of the track valve 300 with an eccentric structure is basically the same as the process of the opening stages I to II of the track valve 100 with a non-eccentric structure, except that after the valve 300 is fully opened, there is no process in which the valve stem 7 continues to move upward and is clamped by the valve core 13 and the bracket 2 respectively. That is, the track groove on the valve stem 7 has only the G section (the straight groove section I of the track groove) and the F section (the spiral groove section II of the track groove) from bottom to top, and no E section (the straight groove section III of the track groove). In the final stage of the full opening of the valve 300, the valve stem 7 is located at the bottom of the valve stem 7. The eccentric design between the valve core 13 upstream of the medium and the bracket 2 (which can also be the valve core in gas-phase applications) downstream of the valve stem 7 allows the valve core 13 and bracket 2 to rotate eccentrically at a certain angle, respectively, and then approach and cling to their respective valve seats 12, 12' and / or the sealing rings or packings on the valve seats. This prevents the medium from flowing between the valve core 13 / bracket 2 and the inner wall of the valve body 1, thereby preventing erosion and wear of the outer surface of the valve core 13 / bracket 2 and the corresponding valve seats 12, 12' or their sealing rings or packings. Furthermore, the close contact of the valve core 13 / bracket 2 with the valve seats 12, 12' or their sealing rings or packings also prevents vibration.

[0131] Typically, when used as a blind flange valve, the support 2 on the downstream side of the medium is replaced by the valve core 13'. To replace the blind flange in the pipeline, the valve body 1 of the track valve is provided with an inlet and outlet for displacement or discharge, and conventional valves 19 and 19' are installed accordingly, as described in the previous embodiment 3 in conjunction with Figure 4.

[0132] The above description is only part of the embodiments of the present invention, and its protection scope is not limited thereto; the present invention can be widely applied to pipelines under various working conditions. Any technician familiar with this technical field, within the technical scope disclosed by the present invention, can make equivalent replacements, changes or combinations based on the technical solutions and inventive concepts of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A track valve, comprising a valve body, a valve stem, a valve cover, a valve seat, a valve core and an actuator, wherein the valve core has two petals, which are respectively located on both sides of the valve stem; the valve stem passes through the valve cover, a track groove is provided on the valve stem, a corresponding guide pin is fixed on the valve body, and the E1 end of the valve stem is connected to the actuator; characterized in that: Also included is a track beam for connecting the valve stem and the valve core; The track beam is an axisymmetric structure, comprising a middle beam and tracks located on both sides of the middle beam; The middle beam is provided with a plug hole in the center, and the E2 end of the valve stem is vertically inserted into the plug hole; the valve stem is provided with a limit position structure at the position corresponding to the upper and lower positions of the valve stem and the plug hole; The valve body is provided with a supporting surface on its inner wall opposite to the end of the valve stem E2, for supporting the valve core; The two tracks are respectively inclined from top to bottom toward the valve stem axis direction, and are respectively embedded in the track grooves correspondingly arranged on the valve core located on the outside thereof and are gap-matched with the track grooves.

2. The track valve according to claim 1, characterized in that: The insertion hole has space in only one direction dimension for the E2 end of the valve stem inserted therein to translate therein, and the direction dimension is along the direction spanning the two tracks.

3. The track valve according to claim 1, characterized in that: The cross-sectional profile of the track beam along the axial direction of the valve stem is an isosceles trapezoid, and the cross-sectional profile perpendicular to the axial direction of the valve stem is a short "H" shape; the plug hole is a through hole, which corresponds to a central rectangular hole on the short "H" cross section; the two tracks constitute the two wings of the short "H" cross section; The end E2 of the valve stem is correspondingly configured as a square shaft section having a cross section matching the rectangular hole; The track groove on the valve core is in a short "┣" shape or "┫" shape in a cross section perpendicular to the axial direction of the valve stem, and the track and a small section of the middle beam connected thereto are embedded therein.

4. The track valve according to claim 1, characterized in that: It also includes a cantilever rod, which is an elastic thin rod with a fixed end and a cantilever end, wherein the fixed end is connected below the track, and the cantilever end is in clearance fit with the track groove on the valve core.

5. The track valve according to claim 1, characterized in that: The center lines L1 and L2 of the two valve cores are respectively on both sides of the axis of the valve stem, and the distances therebetween are ΔL1 and ΔL2 respectively; When the track valve is in a fully open state, the planes M1 and M1' where the outer edges of the sealing surfaces located on the upstream and downstream sides of the medium are located are not perpendicular to the axis L of the medium inlet and outlet on the valve body; When the track valve is in the fully closed state, the plane N1 where the outer edge of the sealing surface of the valve core located on the upstream side of the medium or the plane N1' where the outer edge of the sealing surface of the valve core located on the downstream side of the medium is not perpendicular to the axis L of the medium inlet and outlet.

6. The track valve according to claim 5, characterized in that: The two valve cores are symmetrical with respect to the center of the valve body, ΔL1 and ΔL2 are equal in size, and When the track valve is in its fully open or fully closed state, the planes are M1 / / M1', N1 / / N1'.

7. The track valve according to claim 1, characterized in that: The center line of the valve core is lower than the center line of the valve seat.

8. The track valve according to any one of claims 1 to 7, characterized in that: The valve core of the valve located at the downstream side of the medium is replaced by a bracket.

9. A structure using a track valve as claimed in any one of claims 1 to 7, characterized in that: The valve body of the track valve is provided with an inlet and an outlet in a direction perpendicular to the axis of the medium inlet and outlet, and conventional valves are installed correspondingly.

10. A structure using the track valve as claimed in claim 8, characterized in that: The two track valves are arranged adjacent to each other, and inlets and outlets are respectively provided on two radial sides of the pipeline between the two and conventional valves are installed correspondingly.

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