High-temperature and high-pressure self-sealing gate valve
By setting a locking groove and a four-open ring limit groove structure in the high-temperature and high-pressure self-sealing gate valve, the non-metal self-sealing ring is prevented from overcompressing during abnormal pressure boosting, the problem of self-sealing ring seal failure is solved and the sealing performance is ensured. and security.
Patent Information
- Application Number
- CN202421172971.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-27
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2034-05-27
AI Technical Summary
The non-metal self-sealing ring of the existing high-temperature and high-pressure self-sealing gate valve is prone to over-compression during abnormal pressure boost, resulting in seal failure and leakage, and lack of a limit structure to prevent this situation.
Set a fixing groove on the inner wall of the valve body and install four open rings. The four open rings are fixed by the fastening assembly. The limit groove is set at the lower part of the inner circle of the four open rings. When the valve cavity is abnormally pressurized, the valve cover is sealed. Abuts against the limit slot to prevent further upward movement and prevents excessive compression of the non-metallic self-sealing ring.
It effectively prevents excessive compression of the non-metallic self-sealing ring, ensures sealing performance, avoids leakage drawbacks, and reflects the pressure through the limiting groove, providing safety guarantees.
Smart Images
Figure CN222334657U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of gate valves, in particular to a high-temperature and high-pressure self-sealing gate valve. Background Art
[0002] The valve is a control device in the fluid delivery system. It is a mechanical product with a movable mechanism used to control the flow of the medium in the pipeline. It has the functions of diversion, interception, regulation, flow control, diversion or pressure regulation, and pressure relief. Valves are widely used in various fields of national economy and people's livelihood that require fluid (liquid, gas, gas-solid, liquid-solid) control, such as petroleum, natural gas, petrochemical, oil refining and coal deep processing and pipeline transportation systems; marine engineering and marine oil and gas systems; chemical, pharmaceutical and food production systems; power production systems of hydropower, thermal power and nuclear power; new energy systems such as hydrogen energy production, storage and transportation applications, solar thermal, geothermal, and solar energy applications; water supply and drainage, heating and gas systems for urban and industrial applications; metallurgical production systems; fluid systems for aviation, ships, vehicles and various sports machinery; water conservancy projects, forests, grain and oil planting irrigation and drainage systems. Valves with various special properties are also used in military fields such as nuclear fuel and nuclear technology, aerospace, aviation, and ships.
[0003] Due to the variety of systems, fluids and environments in which valves operate, valves have a variety of designs and types. Valves can be divided into shutoff valves, check valves, diverter valves, safety valves, regulating valves, etc. according to their use and function; they can be divided into vacuum valves, low-pressure valves, medium-pressure valves, high-pressure valves and ultra-high-pressure valves according to pressure; they can be divided into high-temperature valves, medium-temperature valves, normal-temperature valves, low-temperature valves and ultra-low-temperature valves according to operating temperature; they can be divided into non-metallic valves and metal valves according to valve body materials. At present, the most common types of valves include gate valves, globe valves, ball valves, butterfly valves, diaphragm valves, plug valves, check valves, safety valves, pressure reducing valves, steam traps, etc.
[0004] Among various types of valves, gate valves are the most common in actual industrial applications. The principle of the gate valve is that the gate moves vertically along the inner axis of the valve body driven by the power source, and is used to cut off the medium in the transmission pipeline, that is, fully open or fully closed. The main structure of the gate valve consists of several parts such as the valve stem, valve cover, valve seat, gate, and valve body. It can be used in a wide range of temperature, and can be used in both low-temperature and high-temperature conditions. Due to different media, its properties are also different, so valve materials with different performances can be used to adapt to the media. Gate valves are commonly used in steam pipelines such as thermal power plants and refineries, and are widely used in oil and natural gas transmission pipelines, crude oil transmission pipelines and storage equipment, and slurry pipeline transmission lines.
[0005] Gate valves usually have single-disc, double-disc, wedge-type, parallel-type and other structural designs. Among them, wedge-type double-disc (Z42, Z62 series) and wedge-type elastic gate (Z40, Z60 series) are the most widely used. When the former is closed, the gate automatically fits the valve seats on both sides and automatically compensates for the processing position error of the wedge angle; the latter relies on the elastic groove in the middle of the gate and the axial thrust of the valve stem to compensate for the processing position error of the wedge angle. Both can achieve better sealing effects.
[0006] When water in a closed container is heated, the volume of the water increases and cannot diffuse, causing the pressure to rise. Since the volume expansion of water when it vaporizes is much greater than the expansion of the valve body material, an abnormal pressure increase occurs, causing the valve body to be damaged. There is not only water in the valve body, but also a mixture of water and steam. In valves used for oil pipelines and liquefied natural gas, since there is no room for the fluid to diffuse, heating the valve in a closed state (including solar heating) will cause abnormal pressure increase. Figure 1 As shown, the horizontal axis represents the temperature to which the water is heated (℃), the vertical axis represents the pressure rise caused by the heating of the water (bar), and the black curve in the coordinate graph represents the volume percentage of water trapped in the valve cavity. When the water filling volume is 100%, the temperature rises to 60℃-70℃, and the pressure rises to 50MPa; when the water filling volume is 30%, it is heated to 500℃ and the internal pressure reaches 50MPa.
[0007] The main causes of abnormal pressure rise in valves are wedge-type gate valves and parallel two-way sealing gate valves. This is because when these valves are fully closed, the valve is sealed and the body cavity is filled with fluid. After heating, the fluid in the body cavity evaporates and expands, resulting in abnormal pressure rise. In particular, the bypass valve of the boiler feed water heater in thermal power plants is filled with water in the normally closed valve. When starting, high-temperature fluid flows at the inlet and outlet sides of the valve, and the valve is heated, causing abnormal pressure rise.
[0008] Due to the excellent sealing on both sides of the wedge gate valve and the parallel double-disc gate valve, the pressure in the middle cavity will increase abnormally in some cases. That is, when the high-temperature and high-pressure fluid (liquid or gas) is blocked in the middle cavity of the valve, if the temperature of the fluid on the upstream side rises, the temperature of the fluid in the middle cavity will be increased synchronously due to heat transfer. Since the volume of the middle cavity cannot be expanded, when the blocked middle cavity fluid changes from a cold state to a hot state, the liquid may vaporize rapidly, resulting in a sharp increase in pressure. The increased pressure is often geometric.
[0009] The consequences of valve overpressure are very serious. When the valve cavity is abnormally pressurized, the working stress of its pressure-bearing parts and opening and closing parts (such as the use stress of the valve stem and the gate frame) will increase sharply, and the driving force of the drive mechanism will be overwhelmed and even unable to start. In serious cases, the valve stem will break, the gate frame will break, and the motor will burn out. These phenomena are common in many high-pressure and large-diameter gate valves. Many users often complain that this is the gate "seizing". In fact, the real reason for "seizing" is often the "invisible killer" of abnormal pressure increase in the middle cavity.
[0010] A typical case is when the Z962Y series wedge-type double-disc gate valve is used in the water supply system and bypass of a thermal power plant. This type of valve is generally closed after a cold water pressure test. When the unit is started and the system temperature rises to 250℃-300℃, the temperature rises sharply and the cold water temperature in the closed valve body cavity will rise sharply and vaporize simultaneously, increasing the fluid volume and increasing the pressure. The pressure acts on the valve cover and pushes the valve cover up, causing the non-metallic self-sealing ring between the valve cover and the valve body to be over-compressed. Since the valve cover rises to a height that exceeds the allowable compression of the non-metallic self-sealing ring, opening the valve at this time will cause the vaporized steam in the cavity to spray out and cause a safety accident.
[0011] The formation of abnormal pressure rise will occur in a surprisingly similar way in many gate valve applications, because the two major factors that cause it are similar in many industrial systems, that is, the system medium changes from cold to hot after startup; the gate is closed in the cold state and opens in the hot state. Therefore, if no measures are taken for the system, the damage to the system by abnormal pressure rise is almost inevitable, and it mainly has the following three hazards:
[0012] (1) Damage to the valve itself
[0013] The strength of the valve housing, valve cover and valve stem parts is generally designed based on the nominal pressure of the valve. When the pressure is abnormally increased, the opening pressure will increase exponentially, causing the use stress of related parts to increase exponentially. When the actual stress of the material exceeds the allowable stress, the high-stress parts will fracture and fail, causing the valve to be unable to open and the entire valve to be damaged or scrapped.
[0014] (2) Damage to system security
[0015] Obviously, it is very dangerous for the shell, valve cover and other pressure-bearing parts to be over-pressurized. Once over-pressurized, their weak parts may be perforated first, causing the medium to leak out; their packing and self-sealing ring parts are often flushed out by high-pressure fluid, causing a large amount of medium to leak out. When the medium is high-temperature gas, toxic gas, or harmful gas, it will be more serious and may even cause damage to equipment and personnel.
[0016] (3) Huge losses to production control process
[0017] The normal opening and closing of valves is the key to various industrial process control. Once this control cannot be achieved, the system will be paralyzed and need to be shut down for maintenance, which will cause huge direct or indirect losses.
[0018] At present, the self-sealing rings of high-temperature and high-pressure self-sealing gate valves generally use non-metallic self-sealing rings, which use a metal angle structure, but the self-sealing valve cover is not provided with a limit structure to prevent the self-sealing ring from exceeding the compression limit. Figure 2 As shown, a check ring 02 is fixed to the upper part of the valve body 01 of the existing high-temperature and high-pressure self-sealing gate valve, and the self-sealing valve cover 03 is connected to the check ring 02 through a check bolt 04 and a check nut 05. The valve body 01 is located near the position between the inner check ring 02 and the self-sealing valve cover 03 and is provided with four open rings 06, a pressure plate 07 and a non-metallic self-sealing ring 08 from top to bottom.
[0019] However, the disadvantage of this structure is that the self-sealing valve cover 03 adopts a conventional general structure, that is, there is no limit structure on the self-sealing valve cover 03 to prevent the non-metallic self-sealing ring 08 from being infinitely compressed. Since the non-metallic self-sealing ring 08 is usually made of flexible graphite, which is a compressible material, it cannot be over-compressed to ensure its sealing, that is, the compression amount of the non-metallic self-sealing ring 08 cannot exceed the compression margin to ensure its sealing. At present, the recommended compression amount of the non-metallic self-sealing ring 08 made of flexible graphite is (12±5)%, that is, the maximum allowable compression amount of the non-metallic self-sealing ring 08 is 17%. Once the compression amount of the non-metallic self-sealing ring 08 exceeds this value, the non-metallic self-sealing ring 08 will be crushed and lose its sealing effect.
[0020] It can be seen that how to provide a high-temperature and high-pressure self-sealing gate valve that can prevent the non-metallic self-sealing ring from being crushed is a problem that needs to be solved urgently. Utility Model Content
[0021] The purpose of the utility model is to provide a high-temperature and high-pressure self-sealing gate valve to solve the problems existing in the above-mentioned prior art, and to prevent the non-metallic self-sealing ring from being crushed and to avoid the leakage disadvantage caused by the failure of the seal due to excessive compression of the non-metallic self-sealing ring.
[0022] To achieve the above purpose, the utility model provides the following solutions:
[0023] The utility model provides a high-temperature and high-pressure self-sealing gate valve, comprising a valve body and a self-sealing valve cover, wherein a check ring is fixed on the upper part of the valve body, the self-sealing valve cover is arranged in the valve body and is located below the check ring, and the self-sealing valve cover is connected to the check ring through a check bolt and a check nut, and a four-open ring, a pressure plate and a non-metallic self-sealing ring are arranged in sequence from top to bottom in the valve body at a position close to the check ring and the self-sealing valve cover; a clamping groove is arranged on the inner wall of the valve body, and the clamping groove is used to install the four-open ring, and the outer circular surface of the four-open ring can be embedded in the clamping groove and fixedly connected to the valve body through a fastening component; a limiting groove is arranged at the lower part of the inner circular surface of the four-open ring, and when the valve middle cavity of the valve body is abnormally pressurized, the limiting groove can abut against the self-sealing valve cover to limit the upward displacement of the self-sealing valve cover, so that the compression amount of the non-metallic self-sealing ring is less than its allowable compression amount.
[0024] Preferably, the fastening assembly includes a plurality of process screws.
[0025] Preferably, the four open rings are evenly distributed with a plurality of process screw holes along the circumferential direction, and the process screw holes extend radially along the four open rings; the side wall of the valve body is evenly distributed with a plurality of process holes along the circumferential direction, and the process holes penetrate the clamping groove and extend radially along the clamping groove; the process screws are arranged in a one-to-one correspondence with the process screw holes and the process holes.
[0026] Preferably, four process screw holes are provided, and the four process screw holes are respectively located in the middle of the four sub-rings of the four-open ring.
[0027] Preferably, the non-metallic self-sealing ring is a flexible graphite non-metallic self-sealing ring.
[0028] Compared with the prior art, the utility model has achieved the following technical effects:
[0029] The high-temperature and high-pressure self-sealing gate valve provided by the utility model includes a valve body and a self-sealing valve cover. By arranging a fixing groove on the inner wall of the valve body, the outer cylindrical surface of the four-open ring is embedded in the fixing groove, and the four-open ring is fixedly connected to the valve body by a fastening assembly, so as to complete the installation of the four-open ring; by arranging a limiting groove at the lower part of the inner cylindrical surface of the four-open ring, when the pressure in the valve cavity is abnormally increased, the self-sealing valve cover moves upward under the action of the increased pressure until it abuts against the limiting groove. At this time, the self-sealing valve cover is subjected to the resistance of the four-open ring and cannot continue to move upward, and it is also impossible to continue to compress the non-metallic self-sealing ring, so that the compression amount of the non-metallic self-sealing ring is less than its allowable compression amount, thereby ensuring the sealing performance of the non-metallic self-sealing ring. The utility model limits the self-sealing valve cover through the limiting groove of the four-open ring, effectively preventing the non-metallic self-sealing ring from being crushed, and avoiding the leakage disadvantage caused by the sealing failure of the non-metallic self-sealing ring due to excessive compression. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0031] Figure 1 It is a curve diagram of the pressure increase in the valve cavity caused by the heating of the water (volume percentage) trapped in the valve cavity;
[0032] Figure 2 It is a cross-sectional view of an existing high-temperature and high-pressure self-sealing gate valve.
[0033] Figure 2 In: 01-valve body, 02-check ring, 03-self-sealing valve cover, 04-check bolt, 05-check nut, 06-four-open ring, 07-pressure plate, 08-non-metallic self-sealing ring.
[0034] Figure 3 A cross-sectional view of a high-temperature and high-pressure self-sealing gate valve provided by an embodiment of the utility model;
[0035] Figure 4 for Figure 3 The enlarged view of point A in the middle;
[0036] Figure 5 A schematic diagram of a four-open loop provided in an embodiment of the utility model;
[0037] Figure 6 A cross-sectional view of a four-open ring provided in an embodiment of the utility model;
[0038] Figure 7 A cross-sectional view of a valve body provided in an embodiment of the utility model;
[0039] Figure 8 A cross-sectional view of a non-metallic self-sealing ring provided in an embodiment of the utility model.
[0040] Figure 3-Figure 8 In: 1-valve body, 101-fixing groove, 1011-inner hole surface, 102-valve middle cavity, 103-process hole, 2-self-sealing valve cover, 201-valve cover guide surface, 202-limiting surface, 3-checking ring, 4-checking bolt, 5-checking nut, 6-four open ring, 601-outer cylindrical surface, 602-inner cylindrical surface, 603-limiting groove, 604-process screw hole, 7-pressure plate, 8-non-metallic self-sealing ring. DETAILED DESCRIPTION
[0041] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0042] The utility model aims to provide a high-temperature and high-pressure self-sealing gate valve to solve the problems existing in the prior art, prevent the non-metallic self-sealing ring from being crushed, and avoid the leakage disadvantage caused by the sealing failure caused by the non-metallic self-sealing ring being over-compressed.
[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0044] like Figure 3-Figure 4 As shown, this embodiment provides a high-temperature and high-pressure self-sealing gate valve, including a valve body 1 and a self-sealing valve cover 2. A check ring 3 is fixed on the upper part of the valve body 1. The self-sealing valve cover 2 is arranged in the valve body 1 and is located below the check ring 3. The self-sealing valve cover 2 is connected to the check ring 3 through a check bolt 4 and a check nut 5. A four-open ring 6, a pressure plate 7 and a non-metallic self-sealing ring 8 are arranged in sequence from top to bottom in the valve body 1 near the position between the check ring 3 and the self-sealing valve cover 2; a clamping groove 101 is arranged on the inner wall of the valve body 1, and the clamping groove 101 is provided. The fixing groove 101 is used to install the four-open ring 6. The outer cylindrical surface 601 of the four-open ring 6 can be embedded in the fixing groove 101 and fixedly connected to the valve body 1 through a fastening assembly; a limiting groove 603 is provided at the lower part of the inner cylindrical surface 602 of the four-open ring 6. When the valve middle cavity 102 of the valve body 1 is abnormally pressurized, the limiting groove 603 can abut against the self-sealing valve cover 2 to limit the upward displacement of the self-sealing valve cover 2, so that the compression amount of the non-metallic self-sealing ring 8 is less than its allowable compression amount, thereby ensuring the sealing performance of the non-metallic self-sealing ring 8.
[0045] In this embodiment, the fastening assembly includes four process screws.
[0046] Furthermore, if Figure 5-Figure 6 As shown, four process screw holes 604 are evenly distributed along the circumferential direction on the four-open ring 6, and the four process screw holes 604 are respectively located in the middle of the four sub-rings of the four-open ring 6, and each process screw hole 604 extends along the radial direction of the four-open ring 6; Figure 7As shown, four process holes 103 are evenly distributed along the circumferential direction on the side wall of the valve body 1, and each process hole 103 penetrates the fixing groove 101 and extends radially along the fixing groove 101; the process screws are arranged in a one-to-one correspondence with the process screw holes 604 and the process holes 103; when in use, the process holes 103 are used for the corresponding process screws to tighten the corresponding process screw holes 604 on the four-open ring 6, so that the four-open ring 6 is installed in the fixing groove 101 of the valve body 1, which is convenient for assembly. When disassembling the valve, a special tool can also be used to push out the four-open ring 6 through the process holes 103 to achieve disassembly of the valve.
[0047] It should be noted that if Figure 7 As shown, the side wall of the fixing groove 101 is used as the inner hole surface 1011; Figure 4 As shown, the side of the self-sealing valve cover 2 located below the restraining ring 3 is used as the valve cover guide surface 201, and the top of this part is used as the limit surface 202; when in use, the outer cylindrical surface 601 of the four-open ring 6 can be fitted with the inner hole surface 1011 of the fixing groove 101 through the process screws, so as to facilitate the lifting of the self-sealing valve cover 2 so that the valve cover guide surface 201 and the inner cylindrical surface 602 of the four-open ring 6 (that is, the guide surface of the four-open ring 6) cooperate and guide each other; by fixing the four-open ring 6 in the fixing groove 101 of the valve body 1, the valve cover guide surface 201 of the self-sealing valve cover 2 can move up and down along the inner cylindrical surface 602 of the four-open ring 6, which is used to lift the self-sealing valve cover 2 to achieve the self-tightening seal of the non-metallic self-sealing ring 8, and at the same time, when the valve cavity 102 is abnormally pressurized, it is used for the upward guidance of the self-sealing valve cover 2.
[0048] In this embodiment, if Figure 8 As shown, the non-metallic self-sealing ring 8 is a flexible graphite non-metallic self-sealing ring, and the limiting size of the limiting groove 603 is set according to the compression amount of the flexible graphite non-metallic self-sealing ring. In order to ensure the sealing performance of the flexible graphite non-metallic self-sealing ring, 85% of the allowable compression amount of the flexible graphite non-metallic self-sealing ring is taken as the sealing compression amount, that is, the limiting size of the limiting groove 603. The calculated value is 14.45%, and the trimming value is 15%. Specifically, the limiting size of the limiting groove 603 is 0.15 times the thickness of the flexible graphite non-metallic self-sealing ring.
[0049] When the valve is operating normally, the compression amount of the flexible graphite non-metallic self-sealing ring is 7% of the compression amount for forming the initial seal. At this time, the limit groove 603 does not work. When the valve middle cavity 102 is abnormally pressurized, the self-sealing valve cover 2 moves upward under the action of the boosted pressure. When the limit surface 202 of the self-sealing valve cover 2 abuts against the limit groove 603 of the four-open ring 6, the self-sealing valve cover 2 is subjected to the resistance of the four-open ring 6 and cannot move upward. At this time, the flexible graphite non-metallic self-sealing ring is compressed by another 8%, that is, the total compression amount of the flexible graphite non-metallic self-sealing ring is 15%, which is less than its allowable compression amount of 17%, effectively preventing the flexible graphite non-metallic self-sealing ring from being crushed, and avoiding the leakage disadvantage caused by the flexible graphite non-metallic self-sealing ring being over-compressed and causing its sealing failure.
[0050] The high-temperature and high-pressure self-sealing gate valve provided in this embodiment is particularly suitable for thermal power generation and refining equipment, and has the following advantages:
[0051] First, compared with the traditional high-temperature and high-pressure self-sealing gate valve, the process screw hole 604 on the four-open ring 6 can make the outer cylindrical surface 601 of the four-open ring 6 and the inner hole surface 1011 of the fixing groove 101 of the valve body 1 cooperate, so as to facilitate the lifting of the self-sealing valve cover 2.
[0052] Second, compared with the traditional high-temperature and high-pressure self-sealing gate valve, the non-metallic self-sealing ring 8 is limited by the limiting groove 603 of the four-open ring 6 to prevent the non-metallic self-sealing ring 8 from being over-compressed and losing its sealing performance, thereby causing safety hazards.
[0053] Third, the valve cover guide surface 201 of the self-sealing valve cover 2 can cooperate and guide with the inner circular surface 602 of the four-open ring 6, so as to lift the self-sealing valve cover 2 to realize the self-tightening sealing function of the non-metallic self-sealing ring 8. At the same time, when the valve cavity 102 is abnormally pressurized, it is used to guide the rise of the self-sealing valve cover 2.
[0054] Fourth, the limiting size of the limiting groove 603 on the four-open ring 6 is 15% of the compression of the non-metallic self-sealing ring 8. The compression is a quantitative size and is fed back to the self-sealing valve cover 2. By regularly detecting the size of the self-sealing valve cover 2, the pressure condition of the valve cavity 102 can be determined.
[0055] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of the present invention. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. A high-temperature and high-pressure self-sealing gate valve, comprising a valve body and a self-sealing valve cover, wherein a check ring is fixed to the upper part of the valve body, the self-sealing valve cover is arranged in the valve body and located below the check ring, and the self-sealing valve cover is connected to the check ring through a check bolt and a check nut, and a four-open ring, a pressure plate and a non-metallic self-sealing ring are arranged in sequence from top to bottom in the valve body near the position between the check ring and the self-sealing valve cover; characterized in that: A fixing groove is provided on the inner wall of the valve body, and the fixing groove is used to install the four-open ring. The outer circular surface of the four-open ring can be embedded in the fixing groove and fixedly connected to the valve body through a fastening assembly; a limiting groove is provided at the lower part of the inner circular surface of the four-open ring. When the pressure in the valve cavity of the valve body is abnormally increased, the limiting groove can abut against the self-sealing valve cover to limit the upward displacement of the self-sealing valve cover, so that the compression of the non-metallic self-sealing ring is less than its allowable compression.
2. The high temperature and high pressure self-sealing gate valve according to claim 1, characterized in that: The fastening assembly includes a plurality of process screws.
3. The high temperature and high pressure self-sealing gate valve according to claim 2, characterized in that: The four open rings are evenly distributed with a plurality of process screw holes along the circumferential direction, and the process screw holes extend radially along the four open rings; the side wall of the valve body is evenly distributed with a plurality of process holes along the circumferential direction, and the process holes penetrate the fixing grooves and extend radially along the fixing grooves; the process screws are arranged in a one-to-one correspondence with the process screw holes and the process holes.
4. The high temperature and high pressure self-sealing gate valve according to claim 3, characterized in that: There are four process screw holes, and the four process screw holes are respectively located in the middle of the four sub-rings of the four-open ring.
5. The high temperature and high pressure self-sealing gate valve according to any one of claims 1 to 4, characterized in that: The non-metallic self-sealing ring is a flexible graphite non-metallic self-sealing ring.