bonnetless gate valve

Abstract

A valve cover-free gate valve, comprising a valve body, a valve rod and a valve plate, the front end of the valve rod is provided with a fitting head, the valve plate is provided with a fitting groove corresponding to the fitting head, the fitting head and the fitting groove are matched to fix the valve rod and the valve plate, an opening and closing cavity is arranged in the valve body, the valve plate connected with the valve rod is arranged in the opening and closing cavity, the valve plate moves up and down in the opening and closing cavity under the driving of the valve rod, the fitting head is inserted into the fitting groove and then rotates by 90 degrees to realize the fixation of the valve rod and the valve plate; the valve body is symmetrically provided with a guide assembly on both sides of the opening and closing cavity, the guide assembly is integrally formed in the opening and closing cavity, and the valve plate is provided with a sliding groove corresponding to each guide assembly, the guide assembly moves in the sliding groove. The valve has the advantages that: the fitting head and the fitting groove are matched with the mortise and tenon structure to rotate by 90 degrees for fixation, the traditional fastener is saved, the connection between the valve rod and the valve plate is simplified, the parts and assembly difficulty are reduced; the guide assembly is integrally formed in the valve body, the steps are saved, the time is saved, the difference is reduced, and the stability is high.

Description

Technical Field

[0001] This utility model relates to a valve, and more particularly to a gate valve without a bonnet. Background Technology

[0002] Gaiterless gate valves are widely used in industries such as petroleum, chemical, water treatment, and energy, especially in high-pressure, high-temperature, or corrosive fluid control scenarios, such as pipeline transportation systems and refinery valve stations. This type of valve features an integrated design, eliminating the traditional gaiter structure and enhancing overall sealing and pressure resistance. During operation, the operator moves the valve stem up and down along the vertical axis by rotating the handwheel or connecting an electric / pneumatic drive. The valve stem, through a connector, drives the valve plate to slide within a guide groove inside the valve body: when the valve plate rises to its highest point, the valve opens, allowing free fluid flow; when the valve plate falls to its lowest point, the valve closes, cutting off fluid flow. This design simplifies the external structure, reduces the risk of leakage, and is suitable for frequent opening and closing operations, but requires strict alignment of the guide rail and valve plate during assembly and maintenance. The entire process relies on precise mechanical linkage to ensure stable operation in harsh environments.

[0003] However, existing technologies have significant drawbacks, primarily in assembly complexity. First, the connection between the valve stem and valve plate typically uses multi-stage threads or pins, requiring high-precision machining and cumbersome assembly steps, increasing manufacturing costs and assembly time, and easily leading to loosening or wear problems. Second, the fit between the valve plate and the guide rail in the valve body is extremely complex, requiring precision milling and adjustment to achieve clearance control; otherwise, jamming or sealing failure may occur. This complexity not only reduces production efficiency but also increases maintenance difficulty, making it more prone to failure under high-pressure conditions, affecting the overall reliability and lifespan of the valve. These problems limit the potential for widespread adoption of bonnetless gate valves in rapid deployment and low-cost applications. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a bonnet-less gate valve that reduces assembly difficulty.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a bonnetless gate valve, comprising a valve body, a valve stem, and a valve plate. The valve stem has an assembly head at its front end, and the valve plate has an assembly groove corresponding to the assembly head. The assembly head and the assembly groove cooperate to fix the valve stem and valve plate. The valve body has an opening / closing cavity, and the valve plate, connected to the valve stem, is disposed within the opening / closing cavity. The valve plate moves up and down within the opening / closing cavity under the influence of the valve stem. The assembly head, inserted into the assembly groove, rotates 90 degrees to fix the valve stem and valve plate. The valve body has symmetrically arranged guide components on both sides of the opening / closing cavity, the guide components being integrally formed within the opening / closing cavity. The valve plate has sliding grooves on both sides corresponding to its respective guide components, allowing the guide components to move within them.

[0006] The beneficial effects of this utility model are as follows: By adopting a mortise and tenon structure with a 90-degree rotation fixing method using the assembly head and assembly groove, the use of traditional fasteners is avoided, significantly simplifying the connection process between the valve stem and the valve plate, and reducing assembly difficulty and the number of parts. The one-piece molded guide component is directly integrated into the valve body's opening and closing cavity, eliminating the need for additional installation steps, reducing assembly time and errors, and enhancing the overall structural integrity and stability. In addition, the valve stem only moves up and down without rotating, and with the keyway and protrusion design, it prevents loosening of the assembly, improving connection reliability and sealing performance. As a preferred embodiment, the assembly head can be designed as a multi-stage stepped structure, including a rod, a fixing platform, etc., with corresponding through grooves and fixing grooves in the assembly groove. During assembly, the rod is first inserted into the through groove, and then rotated to lock the fixing platform into the fixing groove. As another preferred embodiment, the guide component is integrally formed with the valve body using a casting process, with the guide rail directly embedded in the opening and closing cavity wall. When the valve plate moves, the slide groove slides along the guide rail, ensuring smooth guidance and reducing friction and wear. This design also avoids positioning deviations caused by installing guide components separately, improving the valve plate movement accuracy and the overall valve life.

[0007] Furthermore, the assembly head is provided with a support platform, a connecting rod, a fixing platform, and an insert rod in sequence from the end away from the assembly slot toward the assembly slot. The assembly slot is provided with a limit slot, a through slot, a fixing slot, and a through slot respectively corresponding to the support platform, the connecting rod, the fixing platform, and the insert rod. The insert rod has the smallest outer diameter in the assembly head.

[0008] This structure, through a tiered arrangement of abutment, connecting rod, fixing platform, and insert rod, precisely engages with the limiting groove, through groove, fixing groove, and through groove of the assembly slot. This achieves progressive guidance and positioning during assembly, reducing insertion difficulty and the risk of misalignment. The insert rod, being the smallest outer diameter component, preferentially enters the through groove, facilitating initial alignment, reducing assembly force, and improving operational efficiency. Simultaneously, this multi-stage design enhances connection strength, preventing the valve stem from detaching from the valve plate under stress, thus improving the valve's reliability and durability. As a preferred method, the insert rod employs a conical or cylindrical design with a chamfered front end, facilitating its sliding into the through groove during assembly. Subsequently, the connecting rod and fixing platform pass smoothly through the through groove and fixing groove. As another preferred method, the limiting groove and abutment cooperate to form an axial stop, restricting the assembly depth and ensuring that the fixing platform is accurately positioned before locking by rotation. This avoids over-insertion or under-insertion, thereby optimizing assembly accuracy and stability.

[0009] Furthermore, the through slot is symmetrically provided with bow-shaped limiting ears on both sides of the radial direction. The two limiting ears cooperate to form a through slot at the center of the through slot. After the fixed platform rotates at a fixed angle, the two limiting ears cooperate with the two ends of the fixed platform to prevent the assembly head from coming out of the assembly slot.

[0010] The bow-shaped limiting ear, working in conjunction with the through groove, forms a mechanical lock after the fixed platform rotates, effectively preventing the assembly head from accidentally dislodging and enhancing the robustness and safety of the tenon-and-mortise connection. This symmetrical design ensures uniform force distribution, reduces localized stress concentration, and improves the valve's impact resistance under high-pressure environments. Simultaneously, the through groove allows the fixed platform to initially pass through, simplifying assembly steps and preventing jamming. As a preferred option, the inner wall of the limiting ear is provided with an inclined guide surface, allowing the fixed platform to slide into the locking position along the guide surface during rotation, achieving a smooth transition and automatic positioning. Alternatively, the ends of the fixed platform are machined into flat surfaces or grooves, forming surface contact with the bow-shaped curved surface of the limiting ear, increasing the contact area, distributing the load, and thus improving torsional strength and long-term stability.

[0011] Furthermore, the guide assembly includes a guide rail that cooperates with the slide to prevent the valve plate from swinging. The guide rail includes a main body and a guide part. When the valve plate moves from the closed state to the open state, the slide gradually cooperates with the main body through the guide part.

[0012] The main body and guide section of the guide rail work together. During the initial movement of the valve plate, the guide section smoothly guides the slide groove to the main body, avoiding jamming or impact during startup and ensuring smooth, wobbly valve plate lifting and lowering. This design reduces friction loss, extends valve life, and improves opening and closing response speed and accuracy. The introduction of the guide section optimizes the force transmission path, keeping the valve plate moving linearly within the opening and closing chamber, enhancing the sealing effect. As a preferred method, the guide section uses a ramp or curved surface structure. When the valve plate moves, the slide groove first contacts the lower end of the guide section, gradually transitioning to the fully engaged state of the main body, achieving progressive guidance. As another preferred method, the main body is designed as a straight guide rail, matching the groove of the slide groove. The guide section acts as a transition section connecting the ends of the guide rail, absorbing initial deviations through an arc or ramp design, ensuring the stability of the valve plate throughout its entire movement from closed to open.

[0013] Furthermore, the guide portion is an arc surface, and the guide portion gradually engages with the slide groove as the valve plate moves from the closed state to the open state.

[0014] The arc-shaped guide provides a smooth contact surface, gradually increasing the contact area as the valve plate moves from closed to open. This effectively distributes the load and reduces localized wear, preventing jamming and noise. This progressive fit optimizes the motion trajectory, ensuring a smooth transition of the valve plate at the opening / closing point, improving valve operation comfort and reliability. The arc design also adapts to changes in the valve plate's inertia, reducing opening and closing resistance. As a preferred option, the arc-shaped guide employs a continuous change in radius of curvature, with the slide moving from the low point to the high point of the arc surface, achieving stepless acceleration and deceleration. Alternatively, the guide is integrally cast with the main body, with the arc transition section extending to the starting end of the main body. When the valve plate opens, the slide rolls along the arc surface into the main body, reducing sliding friction and improving efficiency.

[0015] Furthermore, the guide assembly also includes a stop rib, the guide portion is disposed on the stop rib, the stop rib cooperates with the outer diameter surface of the valve plate when the guide rail is disengaged from the contact with the slide groove to prevent the valve plate from swinging; the end face of the stop rib corresponding to the valve plate is a vertical surface, and the quadrant point of the valve plate along the radial direction forms a clearance fit with the stop rib.

[0016] The abutment rib provides additional support when the guide rail disengages from the slide groove. Through contact between its vertical surface and the outer diameter surface of the valve plate, it effectively suppresses valve plate sway, ensuring valve stability at extreme positions or during start-up and shutdown. The clearance fit allows for slight radial movement, absorbing thermal expansion or assembly tolerances, avoiding stress concentration or damage caused by rigid contact, while maintaining overall guiding accuracy. This dual protection mechanism enhances valve reliability under dynamic operating conditions. As a preferred option, the abutment rib is designed with an L-shaped structure, with its vertical surface parallel to the valve plate axis. When the valve plate moves to the end of the guide rail, its outer diameter surface forms surface contact with the vertical surface, allowing for moderate floating but limiting excessive offset. Alternatively, the guide section is integrated into the top of the abutment rib. When the slide groove leaves the guide rail, the abutment rib automatically takes over the support, reducing impact through elastic materials or cushioning design to ensure a smooth transition.

[0017] Furthermore, it also includes a sealing assembly, wherein a sealing cavity is formed between the valve stem and the valve body, and the sealing assembly is disposed in the sealing cavity and is used to form a seal on the valve stem. The valve body is provided with a fixing assembly that keeps the sealing assembly in a relative position along the axial direction without moving. The valve body is provided with a sealing step. The sealing assembly includes a sealing ring that cooperates with the sealing step. The sealing ring has a hardness greater than that of the packing and is made of a metal material that is not easy to rust.

[0018] The sealing assembly forms a double barrier through a hard contact seal between the sealing ring and the sealing step, combined with a packing seal, significantly improving the valve stem's sealing performance and preventing media leakage, making it particularly suitable for high-pressure or corrosive environments. The fixing assembly ensures the sealing assembly is axially fixed, preventing displacement due to vibration or pressure changes and enhancing sealing reliability. The metallic material and hardness of the sealing ring provide long-term durability and reduce maintenance requirements. As a preferred option, the sealing ring is made of stainless steel or copper alloy, and the sealing step is an annular boss. The sealing ring forms a metal-to-metal contact seal with the step through clamping force, while packing fills the gap to compensate for minor deformations. As another preferred option, the fixing assembly includes a bracket and bolts. The bracket fits over the upper end of the sealing cavity and is fixed to the valve body by the bolts, applying an axial preload to the sealing assembly to maintain its positional stability.

[0019] Furthermore, the sealing step includes a first contact slope, and the sealing ring is provided with a second contact slope corresponding to the first contact slope. The first contact slope and the second contact slope cooperate to form a sealing contact. The valve body is provided with a first axial contact surface. The sealing ring also includes a U-shaped opening and a second axial contact surface that contacts the second axial contact surface and forms a tight fit. One end of the U-shaped opening is connected to the second contact slope, and the other end is connected to the second axial contact surface. The U-shaped opening covers part of the first contact slope.

[0020] The beveled contact seal allows for axial offset compensation, and the angled design disperses sealing pressure, improving seal reliability and adaptability. The U-shaped opening reduces the contact area, lowering the risk of friction and wear, while the axial contact surface provides an auxiliary seal, ensuring backup even if the bevel fails, thus enhancing overall seal integrity. This combined design optimizes load distribution and extends seal life. As a preferred embodiment, the first and second contact bevels are angled at 30-45 degrees. During assembly, the sealing ring deforms under pressure, and the bevels form a line seal. The U-shaped opening accommodates the valve body protrusion, and the second axial contact surface is elastically pre-tightened to fit tightly against the first axial contact surface, forming a surface seal. As another preferred embodiment, the U-shaped opening of the sealing ring is designed as a semi-closed structure, with the first contact bevel located inside the opening and the second axial contact surface extending outward to form a flange edge, achieving a dual sealing path through bolt fixing.

[0021] Furthermore, the sealing assembly also includes a packing gland, a packing ring, an upper packing, an oil seal, a lower packing, and a packing gasket arranged sequentially from the valve stem toward the valve plate, with the sealing ring being the closest to the valve plate in the sealing assembly; the fixing assembly includes a bracket mounted on the valve body and fasteners for fixing the bracket to the valve body, with the inner diameter surface of the bracket contacting the packing gland and forming a tight fit.

[0022] The multi-layer sealing assembly provides a progressive seal through the stacked arrangement of a packing gland, packing ring, packing, oil seal, and packing pad. The oil seal enhances lubrication and dust protection, while the sealing ring, located close to the valve plate, strengthens the hard seal, forming comprehensive protection. A tight fit between the support and the packing gland ensures uniform axial force transmission, maintains packing compression, and prevents leakage. The optimized fastener distribution of the fixing assembly improves fixing force and sealing stability. As a preferred embodiment, the packing gland is designed as an annular flange with an interference fit to the support's inner bore. Fasteners apply downward pressure, compressing the upper and lower packing through the packing ring, with the oil seal embedded within to form a dynamic seal. Alternatively, the sealing ring is located below the packing pad, directly contacting the sealing step. The fixing force of the support is transmitted to the entire sealing assembly through the packing gland, ensuring a tight fit between layers and accommodating valve stem movement.

[0023] Furthermore, the fasteners are respectively disposed around the four sides of the bracket.

[0024] Fasteners are evenly distributed around the bracket, providing symmetrical fixing force, avoiding stress concentration at single points, ensuring the bracket stably presses against the packing gland, and preventing the sealing assembly from shifting or loosening. This layout enhances the valve's sealing reliability under vibration or pressure fluctuations, while simplifying the assembly process. As a preferred option, bolts or screws are used, one at each of the four corners, fixed to the valve body through threaded holes, resulting in even force distribution on the bracket and radial constraint on the packing gland. Alternatively, the bracket is designed as a square flange with fasteners installed at the four corners, tightened diagonally during assembly to achieve force balance and overall stability of the sealing assembly. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0026] Figure 2 This is an overall structural diagram of the valve stem and valve plate after they are fitted together according to an embodiment of this utility model;

[0027] Figure 3 This is a schematic diagram of the assembly head in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the overall structure of the valve plate in an embodiment of this utility model;

[0029] Figure 5 This is a side view of the valve plate in an embodiment of the present utility model;

[0030] Figure 6 This is a front view of the assembly slot in an embodiment of the present invention;

[0031] Figure 7 This is a cross-sectional view of the valve stem and valve plate after they are fitted together in an embodiment of this utility model;

[0032] Figure 8 This is an enlarged view of the guide component according to an embodiment of the present utility model;

[0033] Figure 9 This is a partial cross-sectional view of the cooperation between the abutment rib and the valve plate in an embodiment of this utility model;

[0034] Figure 10 This is a partial cross-sectional view of the sealing assembly in an embodiment of the present invention;

[0035] Figure 11 This is a partial enlarged view of the fixing component in an embodiment of the present invention;

[0036] Figure 12 This is a partial enlarged view of the contact surface between the sealing ring and the valve body in an embodiment of the present invention (the black line in the figure represents the contact surface between the sealing ring and the valve body). Detailed Implementation

[0037] This utility model embodiment provides a bonnetless gate valve, such as... Figure 1-12 As shown: The valve includes a valve body 1, a valve stem 2, and a valve plate 3. The valve body 1 has an opening / closing cavity 11, which accommodates the valve plate 3 and enables the valve to open and close. An assembly head 21 is provided at the front end of the valve stem 2, and an assembly groove 31 is provided on the valve plate 3 corresponding to the assembly head 21. The assembly head 21 and the assembly groove 31 cooperate to fix the valve stem 2 and the valve plate 3. The valve stem 2 moves vertically up and down and does not rotate; therefore, a keyway (not shown in the figure) is provided on the valve stem 2, and a corresponding protrusion (not shown in the figure) is provided on the bracket 14. The keyway (not shown in the figure) and the protrusion (not shown in the figure) cooperate to prevent the valve stem 2 from rotating during the lifting and lowering process. The valve plate 3 is located in the opening / closing cavity 11 and moves vertically within the opening / closing cavity 11 under the action of the valve stem 2, thereby realizing the opening and closing of the valve. After the assembly head 21 is inserted into the assembly slot 31, it rotates 90 degrees to fix the valve stem 2 and the valve plate 3. This tenon and mortise structure replaces the traditional fastener fixing method, significantly reducing the assembly difficulty. Guide components 12 are symmetrically arranged on both sides of the valve body 1 within the opening and closing cavity 11. The guide components 12 are integrally formed within the opening and closing cavity 11, which reduces the assembly difficulty of installing the guide components 12 within the valve body 1. Slide grooves 32 are provided on both sides of the valve plate 3 corresponding to their respective guide components 12. The slide grooves 32 allow the guide components 12 to move within them, ensuring the smooth lifting and lowering of the valve plate 3.

[0038] The assembly head 21, starting from the end furthest from the assembly slot 31 and moving towards the assembly slot 31, is sequentially provided with a stop platform 211, a connecting rod 212, a fixing platform 213, and an insertion rod 214. The insertion rod 214 has the smallest outer diameter, facilitating the smooth insertion of the assembly head 21 into the assembly slot 31. The assembly slot 31 is provided with a limiting groove 311, a through groove 312, a fixing groove 313, and a through groove 314 corresponding to the stop platform 211, the connecting rod 212, the fixing platform 213, and the insertion rod 214, respectively. The through groove 312 has symmetrically arranged bow-shaped limiting ears 3121 on both radial sides. The two limiting ears 3121 cooperate to form a through groove 3122 at the center of the through groove 312. The shape of the through groove 3122 is adapted to the fixing platform 213. During the assembly process, the fixed platform 213 first passes through the through slot 3122, and then rotates at a fixed angle (i.e., 90 degrees). The two ends of the fixed platform 213 respectively cooperate with their respective limiting ears 3121 to prevent the assembly head 21 from coming out of the assembly slot 31.

[0039] The guide assembly 12 includes a guide rail 121, which engages with a slide groove 32 to prevent the valve plate 3 from swaying. The guide rail 121 includes a main body 1211 and a guide portion 1212. The guide portion 1212 is an arc surface. As the valve plate 3 moves from the closed state to the open state, the slide groove 32 gradually engages with the main body 1211 via the guide portion 1212. This prevents the valve plate 3 from jamming during movement and guides the movement of the valve plate 3. The guide assembly 12 also includes a stop rib 122, on which the guide portion 1212 is disposed. When the guide rail 121 disengages from the slide groove 32, the abutment rib 122 engages with the outer diameter surface of the valve plate 3 to prevent the valve plate 3 from swinging. The end face of the abutment rib 122 corresponding to the valve plate 3 is a vertical surface. The quadrant point of the valve plate 3 along the radial direction forms a clearance fit with the abutment rib 122, which provides space for the valve plate 3 to swing slightly, while ensuring that the main body 1211 engages with the slide groove 32 during movement to prevent swinging.

[0040] The gate valve without a bonnet also includes a sealing assembly 4. A sealing cavity 17 is formed between the valve stem 2 and the valve body 1. The sealing assembly 4 is disposed within the sealing cavity 17 and is used to form a seal on the valve stem 2. The sealing assembly 4 includes a sealing ring 41, a packing gland 42, a packing ring 43, upper packing 44, an oil seal 45, lower packing 46, and a packing pad 47. These components are arranged sequentially from the valve stem 2 toward the valve plate 3, with the sealing ring 41 being closest to the valve plate 3. A sealing step 13 is provided inside the valve body 1. The sealing ring 41 and the sealing step 13 cooperate to form a sealing contact. The sealing ring 41 has a higher hardness than the packing and is made of a metal material that is not easy to rust, such as stainless steel, to enhance the sealing reliability. The sealing step 13 includes a first contact slope 131. The sealing ring 41 is provided with a second contact slope 411 corresponding to the first contact slope 131. The first contact slope 131 and the second contact slope 411 cooperate to form a sealing contact. This slope contact can offset part of the axial displacement. The sealing ring 41 also includes a U-shaped opening 412 and a second axial contact surface 413. A first axial contact surface 132 is provided on the valve body 1, and the second axial contact surface 413 contacts the first axial contact surface 132 to form a tight fit. One end of the U-shaped opening 412 is connected to the second contact slope 411, and the other end is connected to the second axial contact surface 413. The U-shaped opening 412 partially covers the first contact slope 131. By providing the U-shaped opening 412, the contact area is reduced, and the axial contact surface is increased to enhance the sealing effect. A fixing assembly 16 is also provided on the valve body 1. The fixing assembly 16 includes a bracket 14 provided on the valve body 1 and fasteners 15 that fix the bracket 14 to the valve body 1. The fasteners 15 are respectively provided around the bracket 14 to achieve stable fixation. The inner diameter surface of the bracket 14 contacts the packing gland 42 and forms a tight fit. The axial position of the packing gland 42 is fixed by the bracket 14. This axial fixing force is transmitted downward through the packing gland 42 to other parts of the sealing assembly 4, thereby strengthening the seal.

[0041] In the working principle of the bonnetless gate valve, when the valve stem 2 moves up and down, the keyway (not shown in the figure) and the protrusion (not shown in the figure) cooperate to prevent the valve stem 2 from rotating, ensuring that the valve stem 2 only moves up and down. The valve stem 2 drives the valve plate 3 to move up and down in the opening and closing chamber 11: when moving upward, the valve opens; when moving downward, the valve closes. The tenon and mortise structure of the assembly head 21 and the assembly groove 31 (fixed by inserting and rotating 90 degrees) ensures a reliable connection between the valve stem 2 and the valve plate 3, while simplifying the assembly process. The guide rail 121 of the guide assembly 12 guides the slide groove 32 smoothly to the main body 1211 through the arc surface of the guide part 1212, preventing the valve plate 3 from getting stuck; during the movement of the valve plate 3, the main body 1211 and the slide groove 32 cooperate to prevent swaying, and when the guide rail 121 is disengaged, the abutment rib 122 cooperates with the outer diameter surface of the valve plate 3 to maintain stability. The sealing assembly 4 forms a multi-layer seal through the hard contact seal between the sealing ring 41 and the sealing step 13, and the soft seal of the packing and oil seal, which effectively prevents leakage; the bracket 14 and fastener 15 of the fixing assembly ensure that the axial position of the sealing assembly 4 is fixed, thereby improving the sealing durability.

[0042] The above embodiments are merely one preferred embodiment of the present utility model. Ordinary changes and substitutions made by those skilled in the art within the scope of the present utility model's technical solution are all included within the protection scope of the present utility model.

Claims

1. A bonnetless gate valve, comprising a valve body, a valve stem, and a valve plate, wherein an assembly head is provided at the front end of the valve stem, and an assembly groove is provided on the valve plate corresponding to the assembly head, the assembly head and the assembly groove cooperating to fix the valve stem and the valve plate, an opening and closing chamber is provided in the valve body, and a valve plate connected to the valve stem is provided in the opening and closing chamber, the valve plate moving up and down in the opening and closing chamber under the action of the valve stem, characterized in that: After the assembly head is inserted into the assembly slot, it rotates 90 degrees to fix the valve stem and the valve plate. The valve body has guide components symmetrically arranged on both sides of the opening and closing cavity. The guide components are integrally formed in the opening and closing cavity. The valve plate has sliding grooves on both sides corresponding to the respective guide components to allow the guide components to move within them.

2. The gate valve without a bonnet according to claim 1, characterized in that: The assembly head is provided with a support platform, a connecting rod, a fixing platform, and an insert rod in sequence from the end away from the assembly slot toward the assembly slot. The assembly slot is provided with a limit slot, a through slot, a fixing slot, and a through slot respectively corresponding to the support platform, the connecting rod, the fixing platform, and the insert rod. The insert rod has the smallest outer diameter in the assembly head.

3. The gate valve without a bonnet according to claim 2, characterized in that: The through slot is symmetrically provided with arch-shaped limiting ears on both sides of the radial direction. The two limiting ears cooperate to form a through slot at the center of the through slot. The shape of the through slot is adapted to the fixed platform. After the fixed platform is rotated at a fixed angle, the two limiting ears cooperate with the two ends of the fixed platform to prevent the assembly head from falling out of the assembly slot.

4. The gate valve without a bonnet according to claim 1, characterized in that: The guide assembly includes a guide rail that cooperates with the slide to prevent the valve plate from swinging. The guide rail includes a main body and a guide part. When the valve plate moves from the closed state to the open state, the slide gradually cooperates with the main body through the guide part.

5. The gate valve without a bonnet according to claim 4, characterized in that: The guide portion is an arc surface, and it gradually engages with the slide groove as the valve plate moves from the closed state to the open state.

6. The gate valve without a bonnet according to claim 4, characterized in that: The guide assembly also includes a stop rib, the guide portion is disposed on the stop rib, the stop rib cooperates with the outer diameter surface of the valve plate when the guide rail is disengaged from the contact with the slide groove to prevent the valve plate from swinging; the end face of the stop rib corresponding to the valve plate is a vertical surface, and the quadrant point of the valve plate along the radial direction forms a clearance fit with the stop rib.

7. The gate valve without a bonnet according to claim 1, characterized in that: It also includes a sealing assembly, in which a sealing cavity is formed between the valve stem and the valve body, and the sealing assembly is disposed in the sealing cavity to form a seal on the valve stem. The valve body is provided with a fixing assembly that keeps the sealing assembly in a relative position along the axial direction without moving. The valve body is provided with a sealing step. The sealing assembly includes a sealing ring that cooperates with the sealing step. The sealing ring and the sealing step cooperate to form a sealing contact. The sealing ring has a hardness greater than that of the packing and is made of a metal material that is not easy to rust.

8. The gate valve without a bonnet according to claim 7, characterized in that: The sealing step includes a first contact slope, and the sealing ring is provided with a second contact slope corresponding to the first contact slope. The first contact slope and the second contact slope cooperate to form a sealing contact. The valve body is provided with a first axial contact surface. The sealing ring also includes a U-shaped opening and a second axial contact surface that contacts the second axial contact surface and forms a tight fit. One end of the U-shaped opening is connected to the second contact slope, and the other end is connected to the second axial contact surface. The U-shaped opening covers part of the first contact slope.

9. The gate valve without a bonnet according to claim 7, characterized in that: The sealing assembly further includes a packing gland, a packing ring, an upper packing, an oil seal, a lower packing, and a packing gasket arranged sequentially from the valve stem toward the valve plate. The sealing ring is positioned closest to the valve plate in the sealing assembly. The fixing assembly includes a bracket mounted on the valve body and fasteners for fixing the bracket to the valve body. The inner diameter surface of the bracket contacts the packing gland and forms a tight fit.

10. The gate valve without a bonnet according to claim 9, characterized in that: The fasteners are respectively installed around the four sides of the bracket.

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