Safety valve

Abstract

The utility model discloses a safety valve and belongs to the technical field of oil and gas exploitation, in the safety valve, a valve body is provided with a liquid inlet channel and a liquid outlet channel, a valve seat is provided with a communicating channel, the communicating channel communicates with the liquid inlet channel, a valve element is arranged outside the valve seat in a sleeving mode, the valve seat and the valve element are both fixedly installed in the valve body, and the valve element is provided with an inner cavity and a pressure relief hole; the inner cavity is communicated with the communicating channel, and the inner cavity and the liquid discharging channel are both communicated with the pressure relief hole; the valve rod comprises a rod body and a sealing block which are fixedly connected, the valve rod is movably arranged above the valve seat, the sealing block is provided with a first sealing side face, the valve seat is provided with a second sealing side face, and the first sealing side face and the second sealing side face obliquely extend from top to bottom and can be matched in a sealed mode to block the communication channel. According to the safety valve, the problem that after pressure relief work of an existing safety valve is completed, media such as liquid can be left on the spherical concave face of the valve seat, and therefore the follow-up sealing effect of the safety valve is adversely affected can be solved.

Description

Technical Field

[0001] This application belongs to the field of oil and gas extraction technology, specifically relating to a safety valve. Background Technology

[0002] In the process of oil and gas extraction, high-pressure liquids such as fracturing fluid are usually transported through manifolds to pump the liquid downhole. Of course, in order to ensure the safety of on-site operations, safety valves and other devices need to be installed in the manifolds so that pressure relief operations can be carried out using the safety valves in case of overpressure or emergency.

[0003] Currently, safety valves generally utilize a spring to apply preload to maintain a predetermined pressure between the steel ball and the valve seat. Correspondingly, when the pressure in the manifold exceeds the aforementioned predetermined pressure, the high-pressure liquid can push the steel ball through the valve seat, thereby further compressing the spring to open the safety valve and achieve the purpose of pressure relief. After the pressure relief is completed, since the liquid pressure in the manifold is once again less than the predetermined pressure, the spring can restore its deformation and drive the steel ball to re-engage with the valve seat, achieving the purpose of sealing the valve seat.

[0004] As mentioned above, the mating surface between the valve seat and the steel ball is the pressure relief flow surface of the safety valve. Furthermore, in order to ensure relatively good mating stability between the steel ball and the valve seat, in current safety valves, the side surface of the valve seat facing the steel ball is usually provided with a spherical concave surface, so that the mating area between the steel ball and the valve seat is relatively larger.

[0005] Based on the above, during the pressure relief process, as the liquid flows out through the valve seat, after the pressure relief work is completed, some liquid or the particulate matter carried by the liquid will remain on the spherical concave surface of the valve seat. This will hinder the sealing relationship between the steel ball and the valve seat, resulting in the safety valve not sealing properly, which will then have an adverse effect on the operation. Utility Model Content

[0006] The purpose of this application is to provide a safety valve that solves the problem that after the current safety valve completes the pressure relief work, liquid or other media remain on the spherical concave surface of the valve seat, which adversely affects the subsequent sealing effect of the safety valve.

[0007] This application discloses a safety valve, which includes a valve body, a valve seat, a valve core, and a valve stem, wherein...

[0008] The valve body is provided with an inlet channel and an outlet channel, the valve seat is provided with a connecting channel, the connecting channel is connected to the inlet channel, the valve core is sleeved outside the valve seat, and both the valve seat and the valve core are fixedly installed inside the valve body, the valve core is provided with an inner cavity and a pressure relief hole, the inner cavity is connected to the connecting channel, and both the inner cavity and the outlet channel are connected to the pressure relief hole;

[0009] The valve stem includes a fixedly connected rod body and a sealing block, and the valve stem is movably disposed above the valve seat. The sealing block has a first sealing side and the valve seat has a second sealing side. Both the first sealing side and the second sealing side extend obliquely from top to bottom and can be sealed together to block the communication channel.

[0010] This application discloses a safety valve, wherein the valve body has an inlet channel and a outlet channel, the valve seat has a connecting channel that communicates with the inlet channel, the valve core is sleeved outside the valve seat, and both the valve seat and the valve core are fixedly installed inside the valve body. The valve core has an inner cavity and a pressure relief hole, both of which communicate with the pressure relief hole, and the inner cavity communicates with the connecting channel. Thus, when the safety valve is installed in a pipeline and the pipeline needs to be depressurized, the liquid in the pipeline can enter the connecting channel of the valve seat through the inlet channel of the safety valve, and flow into the outlet channel of the valve body through the inner cavity of the valve core and the pressure relief hole, thereby completing the depressurization of the pipeline.

[0011] Of course, the safety valve disclosed in this application also has the ability to open and close based on a set pressure, so that the communication channel of the valve seat can only communicate with the inner cavity of the valve core after the pressure in the pipeline exceeds the set pressure. The device directly used to execute the opening and closing action of the safety valve is the valve stem, which includes a fixedly connected rod body and a sealing block, and is movably disposed above the valve seat. The valve stem also cooperates with other mechanisms or devices to ensure that the entire valve stem has a set downward pressure, so that the safety valve can remain closed when the pressure in the pipeline does not exceed the set pressure. Correspondingly, when the pressure in the pipeline exceeds the set pressure, the valve stem can move upward, releasing the blockage relationship with the communication channel of the valve seat, allowing the communication channel to communicate with the inner cavity of the valve core, and performing pressure relief.

[0012] As described above, the part of the valve stem that directly seals against the valve seat is a sealing block. In this embodiment, the sealing block has a first sealing side, and the valve seat has a second sealing side. The first and second sealing sides can seal against each other to block the communication channel, thereby ensuring that the valve stem and valve seat can form a sealing relationship. Simultaneously, in this embodiment, both the first and second sealing sides extend obliquely downwards. On one hand, during the downward movement of the valve stem relative to the valve seat, the first sealing side provides a guiding function, ensuring that the valve stem and valve seat can form a good alignment. On the other hand, after pressure relief is completed, the liquid remaining on the first sealing side of the valve stem and the second sealing side of the valve seat can flow downwards under gravity, thereby preventing liquid residue on the sealing surfaces of the valve stem and valve seat, ensuring that the sealing relationship between the valve seat and valve stem remains relatively stable, and improving the reliability of the safety valve. Attached Figure Description

[0013] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0014] Figure 1 This is a schematic diagram of the structure of the safety valve disclosed in the embodiments of this application;

[0015] Figure 2 This is a schematic diagram illustrating the fit between the valve core and valve seat in the safety valve disclosed in the embodiments of this application;

[0016] Figure 3 This is a schematic diagram of a portion of the safety valve structure including the valve stem disclosed in an embodiment of this application.

[0017] Figure 4 This is a schematic diagram of the pressure regulating mechanism in the safety valve disclosed in the embodiments of this application;

[0018] Figure 5 This is a schematic diagram of the liquid supply mechanism in the safety valve disclosed in the embodiments of this application.

[0019] A schematic diagram of the control device.

[0020] Figure label:

[0021] 110-Valve body, 111-Inlet channel, 112-Drain channel, 120-Valve seat, 121-Connecting channel, 122-Second sealing side, 131-Valve sleeve, 132-Valve cap, 133-Inner cavity, 134-Pressure relief hole, 141-Rod, 142-Sealing block, 142a-First sealing side, 143-Piston block, 144-Pin, 145-Retaining ring, 150-Piston sleeve, 151-Connecting hole, 160-Bolt, 171-Lip seal, 172-Lip seal, 173-Lip seal, 181-Guide band, 182-Guide band, 191-O-ring, 192-O-ring

[0022] 200-Pressure regulating mechanism, 210-Housing shell, 211-First liquid inlet, 212-First liquid return port, 213-Drain port, 220-Inner core, 221-Second liquid inlet, 222-Second liquid return port, 223-Conveying chamber, 230-Elastic element, 240-Adjusting screw, 250-Spring seat.

[0023] 300-Liquid supply mechanism, 310-Liquid inlet filter, 320-Hydraulic pump, 330-Unloading valve, 340-Check valve, 350-Accumulator, 360-Throttle valve, 370-Return oil filter. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0026] like Figures 1-5 As shown in the figure, this application discloses a safety valve, which includes a valve body 110, a valve seat 120, a valve core and a valve stem. Of course, the safety valve may also include a mechanism or device such as a spring to apply a preset pressure to the valve stem, so as to ensure that the valve stem has a certain downward pressure, and thus keep the safety valve closed when the liquid in the valve seat 120 does not exceed the aforementioned preset pressure. Typically, the valve body 110, valve seat 120, valve core, and valve stem are all made of materials with relatively high structural strength, such as metal. To further improve the service life of the safety valve, in one specific embodiment of this application, the valve seat 120 can be made of corrosion-resistant metal to improve its corrosion resistance. The valve core and valve stem can also be made of corrosion-resistant metal. To reduce the cost of the safety valve, in one specific embodiment of this application, only the parts of the valve core and valve stem that frequently come into contact with the medium can be made of corrosion-resistant metal. Specifically, the valve core may include a valve sleeve 131 and a valve cap 132, and the valve stem may include a stem body 141 and a sealing block 142. The valve sleeve 131 and sealing block 142 have frequent contact with the medium, and the contact area between the valve sleeve 131 and sealing block 142 and the medium is relatively large. Therefore, in this embodiment of the application, the valve sleeve 131 and sealing block 142 can be made of corrosion-resistant metal, while the valve cap 132 and stem body 141 can be made of ordinary metal materials.

[0027] As described above, a safety valve is used to open when the liquid pressure in the pipeline exceeds a preset pressure to provide pressure relief. Therefore, the safety valve has an openable and closable pressure relief channel. Specifically, in the safety valve disclosed in this application embodiment, the valve body 110 has an inlet channel 111 and a outlet channel 112, the valve seat 120 has a connecting channel 121 that communicates with the inlet channel 111, the valve core is sleeved outside the valve seat 120, and both the valve seat 120 and the valve core are fixedly installed inside the valve body 110. The valve core has an inner cavity 133 and a pressure relief hole 134. The inner cavity 133 communicates with the connecting channel 121, and both the inner cavity 133 and the outlet channel 112 communicate with the pressure relief hole 134. More specifically, sealing elements are also provided between the valve seat 120 and the valve body 110, and between the valve seat 120 and the valve core, to ensure a good sealing fit between the valve seat 120, the valve core, and the valve body 110. Specifically, an O-ring 191 is provided between the bottom surface of the valve seat 120 and the valve body 110, and an O-ring 192 is provided between the top surface of the valve seat 120 and the valve core.

[0028] Based on the above structure of the safety valve, when the connecting channel 121 of the valve seat 120 is not blocked by the valve stem, the liquid in the pipeline can enter the safety valve through the inlet channel 111 of the valve body 110, and flow through the connecting channel 121 of the valve seat 120, the inner cavity 133 of the valve core and the pressure relief hole 134 to the drain channel 112 of the valve body 110 to achieve the purpose of pressure relief.

[0029] Of course, in order to ensure that the safety valve can remain in a blocked state when the liquid pressure in the pipeline has not exceeded the preset pressure, the safety valve disclosed in this application includes a valve stem, and the valve stem includes a rod body 141 and a sealing block 142 that are fixedly connected. During the assembly of the safety valve, the valve stem is movably disposed above the valve seat 120, so that the valve stem can move up and down to achieve the purpose of opening and closing the safety valve.

[0030] Meanwhile, in this embodiment, the sealing block 142 is provided with a first sealing side 142a, and the valve seat 120 is provided with a second sealing side 122. During the downward movement of the valve stem, the sealing block 142 can contact the valve seat 120, thereby forming a sealing fit between the first sealing side 142a and the second sealing side 122 to block the communication channel 121, ensuring that the valve stem blocks the valve seat 120, thus closing the safety valve. It should be noted that the sealing fit between the first sealing side 142a and the second sealing side 122 is releasable. Specifically, by moving the valve stem upward, the sealing fit between the valve stem and the valve seat 120 can be released, thereby putting the safety valve in the open state.

[0031] Furthermore, in this embodiment, both the first sealing side 142a and the second sealing side 122 extend obliquely downwards. On the one hand, as the valve stem and valve seat 120 approach each other, the first sealing side 142a and the second sealing side 122 can also provide a guiding function, ensuring a more accurate alignment between the valve stem and the valve seat 120, which can further improve the sealing reliability of the valve stem. On the other hand, after the pressure is released, the liquid remaining on the first sealing side 142a and the second sealing side 122 can flow downwards under the action of gravity, thereby preventing the medium from remaining on the first sealing side 142a and the second sealing side 122, thus preventing it from hindering the subsequent sealing process of the safety valve.

[0032] It should be noted that in the safety valve disclosed in this application embodiment, "upper" and "lower" are relative concepts. "Upper" refers to the position of the valve stem relative to the valve seat 120, and "lower" refers to the position of the valve seat 120 relative to the valve stem. Furthermore, the installation orientation of the safety valve needs to be designed during its use. Specifically, the axial direction of the connecting channel 121 needs to have a vertical component. More specifically, the axial direction of the connecting channel 121 can be made parallel to the vertical direction. This maximizes the prevention of media residue on the first sealing side 142a and the second sealing side 122.

[0033] This application discloses a safety valve, wherein the valve body 110 is provided with an inlet channel 111 and a drain channel 112, the valve seat 120 is provided with a connecting channel 121 and the connecting channel 121 is connected to the inlet channel 111, the valve core is sleeved outside the valve seat 120, and both the valve seat 120 and the valve core are fixedly installed inside the valve body 110. The valve core is provided with an inner cavity 133 and a pressure relief hole 134, the inner cavity 133 and the drain channel 112 are both connected to the pressure relief hole 134, and the inner cavity 133 is connected to the connecting channel 121. Therefore, when the safety valve is installed in a pipeline and the pipeline needs to be depressurized, the liquid in the pipeline can enter the connecting channel 121 of the valve seat 120 through the inlet channel 111 of the safety valve, and flow into the drain channel 112 of the valve body 110 through the inner cavity 133 of the valve core and the pressure relief hole 134, thereby completing the depressurization of the pipeline.

[0034] Of course, the safety valve disclosed in this application embodiment also has the ability to open and close based on a set pressure, so that the communication channel 121 of the valve seat 120 can communicate with the inner cavity 133 of the valve core only after the pressure in the pipeline exceeds the set pressure. The device directly used to perform the opening and closing action of the safety valve is the valve stem, which includes a fixedly connected rod body 141 and a sealing block 142, and is movably disposed above the valve seat 120. The valve stem also cooperates with other mechanisms or devices to ensure that the entire valve stem has a set downward pressure, so that when the pressure in the pipeline does not exceed the set pressure, the safety valve can remain closed. Correspondingly, when the pressure in the pipeline exceeds the set pressure, the valve stem can move upward, releasing the blockage relationship with the communication channel 121 of the valve seat 120, allowing the communication channel 121 to communicate with the inner cavity 133 of the valve core, and performing pressure relief.

[0035] As described above, the part of the valve stem that directly seals and engages with the valve seat 120 is the sealing block 142. In this embodiment, the sealing block 142 is provided with a first sealing side 142a, and the valve seat 120 is provided with a second sealing side 122. The first sealing side 142a and the second sealing side 122 can be sealed and engaged to block the connecting channel 121, thereby ensuring that the valve stem can form a sealing relationship with the valve seat 120. Meanwhile, in this embodiment, both the first sealing side 142a and the second sealing side 122 extend obliquely from top to bottom. On the one hand, during the downward movement of the valve stem relative to the valve seat 120, the first sealing side 142a can provide a guiding effect, ensuring that the valve stem and the valve seat 120 can form a good centering relationship. On the other hand, after the pressure relief is completed, the liquid remaining on the first sealing side 142a of the valve stem and the second sealing side 122 of the valve seat 120 can flow downward under the action of gravity, thereby preventing liquid from remaining on the sealing surfaces of the valve stem and the valve seat 120, ensuring that the sealing relationship between the valve seat 120 and the valve stem is always relatively stable, and improving the reliability of the safety valve.

[0036] As described above, both the first sealing side 142a and the second sealing side 122 extend obliquely from top to bottom. In a specific embodiment of this application, both the first sealing side 142a and the second sealing side 122 are frustum-shaped structures. In this case, by designing the dimensions and other parameters of the first sealing side 142a and the second sealing side 122, the first sealing side 142a and the second sealing side 122 can form a surface mating relationship, thereby enabling the valve stem and the valve seat 120 to form a sealing relationship.

[0037] To improve the sealing specific pressure of the safety valve disclosed in this application, in one specific embodiment, one of the first sealing side 142a and the second sealing side 122 is a frustum-shaped structure, and the other is a spherical convex structure. In this case, a line contact fit can be formed between the first sealing side 142a and the second sealing side 122, which can further improve the sealing reliability between them. The spherical convex structure refers to a spherical structure with its surface protruding outwards.

[0038] More specifically, the first sealing side 142a can be a frustum-shaped structure, and the second sealing side 122 can be a spherical convex structure. In this case, the first sealing side 142a can increase the tightness of the fit between the two by pressing the second sealing side 122 downward, thereby further improving the reliability of the sealing fit relationship between the first sealing side 142a and the second sealing side 122.

[0039] As described above, the valve stem is positioned above the valve seat 120, and during the downward movement of the valve stem, the first sealing side 142a of the valve stem can form a sealing fit with the second sealing side 122 of the valve seat 120. Of course, to ensure that the valve stem can block the communication channel 121, the inner side of the first sealing side 142a of the valve stem sealing block 142, that is, the lower surface of the sealing block 142, or the surface of the sealing block 142 facing the communication channel 121, cannot have an opening. Simultaneously, the dimensions and other parameters of the first sealing side 142a, the second sealing side 122, and the aforementioned lower surface of the sealing block 142 need to be designed to ensure that before the first sealing side 142a and the second sealing side 122 form a sealing fit, the aforementioned lower surface of the sealing block 142 cannot contact the top surface of the valve seat 120, preventing them from contacting each other and hindering the sealing relationship between the first sealing side 142a and the second sealing side 122.

[0040] Optionally, when the first sealing side 142a and the second sealing side 122 are sealed together, the bottom surface of the sealing block 142 facing the valve seat 120 and the top surface of the valve seat 120 facing the sealing block 142 are in contact with each other. In this case, a certain sealing relationship can still be formed between the aforementioned bottom surface of the sealing block 142 and the aforementioned top surface of the valve seat 120, thereby further improving the reliability of the sealing fit between the valve stem and the valve seat 120.

[0041] Considering that the liquid medium in the pipeline will flow out through the top surface of the valve seat 120 during the pressure relief process, and in order to further prevent the medium residue from affecting the subsequent sealing reliability of the safety valve, in another embodiment of this application, when the first sealing side 142a and the second sealing side 122 are sealed together, the bottom surface of the sealing block 142 facing the valve seat 120 and the top surface of the valve seat 120 facing the sealing block 142 are spaced apart from each other. That is, the bottom surface of the sealing block 142 and the top surface of the valve seat 120 are basically unable to contact each other. In this case, even if a small amount of medium remains on the top surface of the valve seat 120, it will not affect the sealing relationship between the valve stem and the valve seat 120.

[0042] Furthermore, the size of the top surface of the valve seat 120 facing the valve stem can be minimized to reduce the amount of medium residue on the top surface of the valve seat 120, thereby further reducing the adverse effect of medium residue on the sealing effect of the safety valve.

[0043] As described above, in the safety valve disclosed in this application embodiment, liquid can flow from the inlet channel 111 through the valve seat 120 and the valve core, and finally be discharged from the outlet channel 112 to the outside of the safety valve. Based on this, in order to improve the discharge efficiency of the safety valve and reduce the retention time of the medium in the safety valve, in this application embodiment, the minimum cross-sectional area of ​​the outlet channel 112 can be greater than the maximum cross-sectional area of ​​the inlet channel 111, so as to prevent the discharge efficiency of the safety valve from being limited by the discharge area of ​​the outlet channel 112, and ensure that the liquid entering the safety valve through the inlet channel 111 can flow out from the outlet channel 112 as soon as possible.

[0044] Furthermore, the drain channel 112 can be a full-bore structure, while the inlet channel 111 can be flexibly configured with structures such as necking holes according to actual needs to achieve a throttling effect.

[0045] To further reduce the time the medium remains in the safety valve, in this embodiment, the valve core can be provided with multiple pressure relief holes 134, and all of the multiple pressure relief holes 134 are connected to the drain channel 112. Of course, each pressure relief hole 134 is also connected to the inner cavity 133, so that the medium entering the inner cavity 133 of the valve core through the inlet channel 111 can flow out quickly through the multiple pressure relief holes 134, and finally be discharged outside the safety valve through the drain channel 112, thereby improving the pressure relief efficiency.

[0046] Furthermore, to enhance the overall pressure relief capacity of the multiple pressure relief holes 134, in this embodiment, the multiple pressure relief holes 134 are spaced apart around the connecting channel 121. In other words, in this embodiment, the multiple pressure relief holes 134 are spaced apart circumferentially along the valve core, allowing the medium in the inner cavity 133 to flow in different directions and be discharged into the drain channel 112 through different pressure relief holes 134, thereby improving the pressure relief efficiency. Of course, when there are multiple pressure relief holes 134, the sum of the drain areas of the multiple pressure relief holes 134 can be designed to make the drain area of ​​the drain channel 112 larger than the sum of the drain areas of the multiple pressure relief holes 134, so as to further prevent the pressure relief efficiency of the multiple pressure relief holes 134 from being ineffectively utilized due to the limited area of ​​the drain channel 112.

[0047] As described above, the valve stem is movably mounted above the valve seat 120. Of course, the valve stem also has an assembly relationship with the valve core. Specifically, the valve stem sealing block 142 is located inside the valve core, and the stem body 141 is movable and sealingly fitted with the valve core. Optionally, the dimensions of the stem body 141 and the sealing block 142 are similar. In this case, the valve stem can be inserted entirely into the valve core through the opening on the valve core, and the sealing block 142 can be fitted with the valve seat 120.

[0048] In another embodiment of this application, in order to appropriately improve the pressure relief efficiency of the safety valve, the size of the connecting channel 121 can be appropriately increased. In this case, in the direction perpendicular to the axial direction of the rod 141, the size of the sealing block 142 can be larger than the size of the rod 141. This ensures that the sealing block 142 can provide a good sealing effect for the connecting channel 121 while reducing the size of the rod 141, thereby reducing the size of the opening on the valve core for the rod 141 to pass through, and improving the overall structural reliability of the valve core.

[0049] Based on the above, in order to ensure that the valve stem and valve core can still complete the assembly work normally, in this embodiment of the application, the valve core may include a valve cap 132 and a valve sleeve 131, with the valve cap 132 located above the valve sleeve 131. Meanwhile, in the valve stem, the stem body 141 and the sealing block 142 are fixedly connected in a detachable manner, so that the stem body 141 and the sealing block 142 can be separated from each other first. After the sealing block 142 of the valve stem is installed in the valve sleeve 131, the valve cap 132 is installed above the valve sleeve 131, so that the sealing block 142 can be installed inside the valve core. Then, the stem body 141 is inserted into the valve core, and the stem body 141 and the sealing block 142 are connected to each other to complete the assembly work of the valve core. More specifically, the rod 141 and the sealing block 142 can be connected by a pin 144, and a retaining ring 145 is provided at the other end of the pin 144 to prevent the pin 144 from separating from the rod 141 and the sealing block 142.

[0050] As described above, the valve core has a mounting hole for mounting the rod 141. The rod 141 is movably and sealingly mounted in the mounting hole. Specifically, a sealing ring or similar device can be used to create a good sealing fit between the rod 141 and the mounting hole of the valve core. More specifically, in this embodiment, a sealing groove can be provided on the inner wall of the mounting hole, and a sealing element can be provided in the sealing groove. The sealing element can be a sealing ring. To improve the sealing effect, a lip seal 171 can be provided between the rod 141 and the mounting hole of the valve core. Furthermore, a guide band 181 can be provided on the side of the seal between the rod 141 and the mounting hole near the valve seat 120. During the movement of the rod 141 relative to the valve seat 120, the guide band provides a guiding and correcting function for the rod 141, further improving the fitting accuracy between the valve stem and the valve seat 120. Correspondingly, a groove can also be provided in the inner wall of the mounting hole corresponding to the position of the guide band to provide a accommodating and limiting function for the guide band.

[0051] As described above, the valve cap 132 is disposed above the valve sleeve 131. Optionally, the two are fixedly connected by bolts or other connecting parts. In another embodiment of this application, the valve body 110 is provided with an installation cavity, which can be located above the liquid inlet channel 111. The valve seat 120, valve sleeve 131 and valve cap 132 can be installed in the installation cavity in sequence. Other devices can be used to stably fix the valve seat 120, valve cap 132 and valve sleeve 131 in the valve body 110. Of course, a sealing element also needs to be provided between the valve cap 132 and the installation cavity of the valve body 110. Optionally, a lip seal 173 is provided between the two to ensure a stable sealing relationship between them. In detail, the safety valve may also include a piston sleeve 150, which is located above the valve cap 132. The lower end of the piston sleeve 150 extends into the mounting cavity where the valve cap 132 and the valve sleeve 131 are located. The piston sleeve 150 is fixedly connected to the valve body 110 by bolts 160 and other connecting parts. By designing the dimensions of the lower end of the piston sleeve 150, while the piston sleeve 150 and the valve body 110 form a stable fixed connection, the lower end of the piston sleeve 150 can compress and confine the valve cap 132, the valve sleeve 131 and the valve seat 120 within the mounting cavity of the valve body 110, so that the aforementioned components form a stable fixed assembly relationship with the valve body 110.

[0052] In addition, as mentioned above, the safety valve is provided with a device or mechanism for providing a preset pressure to the valve stem. In the embodiments of this application, the piston sleeve 150 can be used as part of the device or mechanism for providing the preset pressure, thereby enabling the piston sleeve 150 to have different uses.

[0053] In detail, in the embodiments of this application, the valve stem further includes a piston block 143, which is fixedly connected to the end of the rod body 141 away from the sealing block 142, and the piston block 143 is movably installed in the piston cavity of the piston sleeve 150, so that the piston block 143 can form a piston-fit relationship with the piston sleeve 150 through the piston cavity.

[0054] Meanwhile, in this embodiment, the piston sleeve 150 has a connecting hole 151 at the end away from the valve body 110. The connecting hole 151 is used to communicate with a hydraulic drive device, which is used to supply liquid into the piston chamber to generate a preset pressure between the valve stem and the valve seat 120. Specifically, the hydraulic drive device can directly supply liquid with a certain pressure into the piston chamber through the connecting hole 151. This gives the liquid in the piston chamber a certain pressure, which, under the pressure of the liquid in the piston chamber, can give the valve stem a certain downward pressure, thereby blocking the connecting channel 121 of the valve seat 120. Correspondingly, when the pressure of the liquid in the pipeline where the valve is installed exceeds the downward pressure provided by the valve stem, the valve stem moves upward, thereby opening the connecting channel 121 and allowing the liquid in the pipeline to be discharged through the safety valve for pressure relief. During the depressurization process, a portion of the liquid in the piston chamber can also be discharged out of the piston chamber through the connecting hole 151 to ensure that the valve stem can open normally. Correspondingly, after the safety valve completes the depressurization work, the hydraulic drive device can replenish the liquid in the piston chamber through the connecting hole 151 to make the valve stem maintain the preset downward pressure again.

[0055] That is, in the safety valve disclosed in the embodiments of this application, the hydraulic drive device has the ability to supply and return liquid, and the set value of the downward pressure of the valve stem can be changed by adjusting parameters such as the liquid supply pressure of the hydraulic drive device, so that the opening pressure of the safety valve has adjustable capability.

[0056] To reduce the difficulty of adjusting and controlling the opening pressure of the safety valve, in one specific embodiment of this application, the hydraulic drive device includes a pressure regulating mechanism 200 and a fluid supply mechanism 300. The pressure regulating mechanism 200 includes a housing 210, an inner core 220, an elastic element 230, and an adjusting screw 240. Both the inner core 220 and the elastic element 230 are movably installed in the housing 210. Therefore, by changing the relative position between the inner core 220 and the housing 210, the working state of the pressure regulating mechanism 200 can be changed. The adjusting screw 240 is threaded onto the housing 210 and abuts against the end of the elastic element 230 opposite to the inner core 220. Furthermore, by turning the adjusting screw 240, the degree of mutual compression between the adjusting screw 240 and the elastic element 230 changes, thereby altering the magnitude of the elastic force exerted by the elastic element 230 on the inner core 220, thus achieving the purpose of adjusting the opening pressure of the safety valve. Of course, in order to make the adjustment accuracy of the adjusting screw 240 on the elastic element 230 relatively high, in this embodiment of the application, the end of the elastic element 230 near the adjusting screw 240 may be provided with a spring seat 250, and the adjusting screw 240 and the spring seat 250 cooperate.

[0057] More specifically, in the safety valve disclosed in the embodiments of this application, the housing 210 of the pressure regulating mechanism 200 is provided with a first liquid inlet 211, a first liquid return port 212 and a liquid outlet 213. The first liquid inlet 211 is located on the side of the first liquid return port 212 away from the elastic member 230. The first liquid inlet 211 is connected to the liquid supply mechanism 300, which is used to supply liquid. At the same time, the liquid outlet 213 is connected to the connecting hole 151. The inner core 220 is provided with a conveying chamber 223, a second liquid inlet 221 and a second liquid return port 222. The second liquid inlet 221 is located on the side of the second liquid return port 222 away from the elastic member 230. As described above, the inner core 220 and the housing 210 have the ability to move relative to each other, so that when the inner core 220 is in different positions in the housing 210, the inner core 220 can switch between different states. For example, when the valve stem moves downward, the liquid supply mechanism 300 can supply liquid to the delivery chamber 223 in a timely manner through the first liquid inlet 211 and the second liquid inlet 221, so that the piston chamber and the delivery chamber 223 of the inner core 220 can be kept full of liquid. Conversely, when the valve stem moves upward, the second liquid return port 222 of the inner core 220 can be connected to the first liquid return port 212 of the housing 210. Thus, when the valve stem moves upward and the volume of the piston chamber decreases, the liquid in the piston chamber can be discharged to the outside of the pressure regulating mechanism 200 through the delivery chamber 223, the second liquid return port 222 and the first liquid return port 212, so that the valve stem can open normally.

[0058] More specifically, the liquid supply mechanism 300 may include an inlet filter 310, a hydraulic pump 320, an unloading valve 330, a check valve 340, an accumulator 350, a throttle valve 360, and a return filter 370, wherein, for example... Figure 5 As shown, the inlet filter 310 and the return filter 370 are respectively installed on the inlet pipeline and the return pipeline, and one end of both pipelines is connected to the liquid tank. A hydraulic pump 320 is installed on the inlet pipeline, and the hydraulic pump 320 is connected to the unloading valve 330 to control the liquid supply and return process. A throttle valve 360 ​​is installed on the connecting pipeline between the inlet and return pipelines to allow liquid to flow back to the liquid tank via the connecting pipeline and the return pipeline when the piston chamber and the delivery chamber 223 are full. In addition, the inlet pipeline is connected to the accumulator 350 via a one-way valve 340, and the accumulator 350 is located at the discharge end of the one-way valve 340. The accumulator 350 is used to store pressure.

[0059] More specifically, to ensure the safety valve can provide the required opening pressure, without considering the ratio between the area of ​​the end face of the piston block 143 facing the connecting hole 151 and the cross-sectional area of ​​the opening of the liquid inlet channel 111 facing the sealing block 142, the maximum pressure of the liquid supply mechanism 300 must be higher than the maximum pressure of the liquid to be sealed. Furthermore, this allows the liquid supply mechanism 300 to have a relatively good flow rate, thereby improving the response time of the safety valve.

[0060] Based on the above, in the safety valve disclosed in this application embodiment, the inner core 220 has a replenishing state, a returning state, and a pressure holding state, wherein...

[0061] When the inner core 220 is in the replenishment state, the first liquid inlet 211 is connected to the delivery chamber 223 through the second liquid inlet 221, thereby isolating the first liquid return port 212 from the second liquid return port 222.

[0062] When the inner core 220 is in the liquid return state, the first liquid return port 212 is connected to the delivery chamber 223 through the second liquid return port 222, and the first liquid inlet 211 and the second liquid inlet 221 are isolated from each other.

[0063] When the inner core 220 is in a pressure-holding state, the first liquid inlet 211 and the second liquid inlet 221 are isolated from each other, and the first liquid return port 212 is isolated from the second liquid return port 222.

[0064] More specifically, the opening pressure of the safety valve can be changed by altering the fit between the adjusting screw 240 and the housing 210, thereby adjusting the elastic force exerted by the elastic element 230 on the inner core 220. That is, when the force exerted by the liquid on the valve stem in the pipeline containing the safety valve is less than the force exerted by the elastic element 230 on the valve stem, the elastic element 230 drives the valve stem downwards, and the inner core 220 is in a liquid-filling state. In this situation, the liquid supply mechanism 300 can replenish liquid to the delivery chamber 223 and the piston chamber through the first inlet 211 and the second inlet 221. Of course, when the delivery chamber 223 and the piston chamber are full of liquid, the liquid supply mechanism 300 will also stop supplying liquid. As the pressure of the liquid in the pipeline where the safety valve is located gradually increases, the force exerted by the liquid on the valve stem gradually increases. During this process, the inner core 220 moves away from the piston sleeve 150 and squeezes the elastic element 230. At the same time, as the inner core 220 moves, the liquid supply mechanism 300 continuously replenishes the liquid into the delivery chamber 223, and the communication area between the first liquid inlet 211 and the second liquid inlet 221 gradually decreases until the first liquid inlet 211 and the second liquid inlet 221 are completely isolated. At this time, the liquid supply mechanism 300 can no longer supply liquid to the delivery chamber 223 and the piston chamber, and the force exerted by the liquid on the valve stem in the pipeline where the safety valve is located is basically equal to the force exerted by the elastic element 230 on the valve stem. The pressure regulating mechanism 200 is in a balanced state, and the inner core 220 is in a pressure-holding state. That is, the first return port 212 and the second return port 222 are also isolated from each other.

[0065] As the pressure of the liquid in the pipeline where the safety valve is located continues to rise, when the force exerted by the liquid on the valve stem is greater than the force exerted by the elastic element 230 on the valve stem, the valve stem moves upward, thereby opening the communication channel 121 of the valve seat 120. During this process, the piston block 143 of the valve stem moves towards the connection hole, further reducing the volume of the piston chamber, and driving the inner core 220 to move away from the connection hole to further compress the elastic element 230. As the inner core 220 continues to move upward, the second return port 222 of the inner core 220 can communicate with the first return port 212 of the housing 210, so that the liquid in the delivery chamber 223 and the piston chamber can be discharged outside the pressure regulating mechanism 200 through the second return port 222 and the first return port 212. As the liquid in the pressure regulating mechanism 200 and piston chamber continues to decrease, and the liquid in the pipeline where the safety valve is located continues to depressurize, the pressure in the pipeline decreases, thereby reducing the force exerted by the liquid in the pipeline on the valve stem until it is less than the force exerted by the elastic element 230 on the valve stem. At this point, the elastic element 230 drives the inner core 220 to move closer to the connection hole, and the inner core 220 switches from the return state to the pressure holding state, or even directly to the replenishment state, so that the elastic element 230 can still enable the valve stem to have the same downward pressure.

[0066] As described above, there is a transmission medium, namely the liquid in the piston chamber, between the interaction force between the elastic element 230 and the valve stem. Correspondingly, the force exerted on the valve stem by the pipeline where the safety valve is located is also generated by the pressure of the liquid. Based on this, in order to reduce the magnitude of the elastic force directly provided by the elastic element 230, in this application, the area of ​​the end face of the piston block 143 facing the connecting hole 151 can be larger than the cross-sectional area of ​​the opening of the liquid inlet channel 111 facing the sealing block 142. That is, the area of ​​the liquid in the pipeline acting on the valve stem is smaller than the area of ​​the liquid in the piston chamber acting on the valve stem. This allows the elastic element 230 to provide only a relatively small elastic force, while ensuring that the pressure on the two ends of the valve stem is equal through a relatively large acting area. On the one hand, this reduces the design requirements of the pressure regulating mechanism 200 and the liquid supply mechanism 300; on the other hand, it also reduces the overall size of the safety valve. More specifically, the area of ​​the end face of the piston block 143 facing the connecting hole 151 can be more than twice the cross-sectional area of ​​the opening of the liquid inlet channel 111 facing the sealing block 142.

[0067] By employing the above technical solution, since sealing of high-pressure liquids can be achieved using relatively low hydraulic control force, the safety valve disclosed in this application embodiment can be applied to pressure relief scenarios with relatively high pressure. That is, in this application embodiment, the output pressure of the liquid supply mechanism 300 can be reduced, and its maximum pressure can be the ratio between the maximum pressure of the liquid to be sealed and the aforementioned area ratio. More specifically, the safety valve disclosed in this application embodiment can be applied to pipelines exceeding 140 MPa, providing overpressure protection, and can even provide an opening pressure of 175 MPa, with relatively high stability.

[0068] As described above, the piston block 143 is movably installed in the piston cavity. To ensure relatively good sealing of the piston cavity formed between the piston block 143 and the piston sleeve 150, a sealing element is provided between the piston block 143 and the piston sleeve 150 in this embodiment. Specifically, the sealing element can be a sealing ring. In one specific embodiment, the sealing element can be a lip seal 172, and a groove can be formed on the outer wall of the piston block 143, with the lip seal 172 installed in the aforementioned groove to improve the reliability of the lip seal 172. Furthermore, a guide band 182 can be provided on the side of the lip seal 172 facing the connection hole to provide guidance and alignment for the piston block 143, making the movable fit between the piston block 143 and the piston sleeve 150 smoother. Similarly, another groove can be provided on the outer wall of the piston block 143 to provide a limiting function for the guide band 182.

[0069] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0070] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A relief valve characterized by, The valve body (110) is provided with an inlet channel (111) and a discharge channel (112), the valve seat (120) is provided with a communication channel (121), the communication channel (121) is communicated with the inlet channel (111), the valve core is sleeved outside the valve seat (120), and the valve seat (120) and the valve core are fixedly installed in the valve body (110), the valve core is provided with an inner cavity (133) and a pressure relief hole (134), the inner cavity (133) is communicated with the communication channel (121), and the inner cavity (133) and the discharge channel (112) are both communicated with the pressure relief hole (134). The valve rod includes a rod body (141) and a sealing block (142) fixedly connected, and the valve rod is movably arranged above the valve seat (120), the sealing block (142) is provided with a first sealing side surface (142a), the valve seat (120) is provided with a second sealing side surface (122), the first sealing side surface (142a) and the second sealing side surface (122) are both inclined from top to bottom, and the two can be sealingly matched to block the communication channel (121). One of the first sealing side surface (142a) and the second sealing side surface (122) is a circular truncated cone side surface structure, and the other is a spherical convex structure.

2. The safety valve of claim 1, wherein In the case that the first sealing side surface (142a) and the second sealing side surface (122) are sealingly matched, the bottom surface of the sealing block (142) towards the valve seat (120) and the top surface of the valve seat (120) towards the sealing block (142) are spaced apart from each other.

3. The safety valve of claim 1, wherein The minimum cross-sectional area of the discharge channel (112) is greater than the maximum cross-sectional area of the inlet channel (111).

4. The safety valve of claim 1, wherein The valve core is provided with a plurality of pressure relief holes (134), a plurality of pressure relief holes (134) are arranged at intervals around the communication channel (121), and each pressure relief hole (134) is communicated with the discharge channel (112).

5. The safety valve of claim 4, wherein In the direction perpendicular to the axial direction of the rod body (141), the size of the sealing block (142) is greater than the size of the rod body (141), the valve core includes a valve cap (132) and a valve sleeve (131), the valve cap (132) is located above the valve sleeve (131), the rod body (141) and the sealing block (142) are detachably fixedly connected, and the valve cap (132) is provided with a mounting hole, and the rod body (141) is movably and sealingly mounted in the mounting hole.

6. The safety valve of claim 1, wherein ​ 7. The safety valve of claim 1, wherein The safety valve further comprises a piston sleeve (150) fixedly connected with the valve body (110), the valve rod further comprises a piston block (143) fixedly connected with one end of the rod body (141) away from the sealing block (142), and the piston is movably arranged in a piston cavity of the piston sleeve (150), one end of the piston sleeve (150) away from the valve body (110) is provided with a communication hole (151) for communicating with a hydraulic driving device, and the hydraulic driving device is used for delivering liquid into the piston cavity to generate a preset extrusion force between the valve rod and the valve seat (120).

8. The safety valve of claim 7, wherein, The hydraulic driving device comprises a pressure adjusting mechanism (200) and a liquid supply mechanism (300), the pressure adjusting mechanism (200) comprises a shell (210), an inner core (220), an elastic member (230) and an adjusting screw (240), the inner core (220) and the elastic member (230) are movably arranged in the shell (210), the adjusting screw (240) is threadedly arranged in the shell (210) and abuts against one end of the elastic member (230) away from the inner core (220), the shell (210) is provided with a first liquid inlet (211), a first liquid return port (212) and a liquid discharge port (213), the first liquid inlet (211) is located on one side of the first liquid return port (212) away from the elastic member (230), the first liquid inlet (211) is connected with the liquid supply mechanism (300), the liquid supply mechanism (300) is used for supplying liquid, the liquid discharge port (213) is communicated with the communication hole (151), the inner core (220) is provided with a delivery cavity (223), a second liquid inlet (221) and a second liquid return port (222), the second liquid inlet (221) is located on one side of the second liquid return port (222) away from the elastic member (230), and the inner core (220) has a liquid supplementing state, a liquid returning state and a pressure maintaining state. When the inner core (220) is in the liquid supplementing state, the first liquid inlet (211) is communicated with the delivery cavity (223) through the second liquid inlet (221), and the first liquid return port (212) is isolated from the second liquid return port (222); When the inner core (220) is in the liquid returning state, the first liquid return port (212) is communicated with the delivery cavity (223) through the second liquid return port (222), and the first liquid inlet (211) and the second liquid inlet (221) are isolated; When the inner core (220) is in the pressure maintaining state, the first liquid inlet (211) and the second liquid inlet (221) are isolated, and the first liquid return port (212) and the second liquid return port (222) are isolated.

9. The safety valve of claim 7, wherein, The area of the end face of the piston block (143) toward the communication hole (151) is greater than the sectional area of the opening of the liquid inlet channel (111) toward the sealing block (142).

10. The safety valve of claim 7, wherein A lip seal and a guide belt are arranged between the piston block (143) and the piston sleeve (150).

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