Low frequency cleaning maintenance pipe gate valve

Abstract

The application discloses a low-frequency cleaning and maintaining type pipeline gate valve and belongs to the technical field of pipeline valves, which comprises a valve body, a sunken guide groove is formed at the inner cavity section of the valve body, and a gate plate is slidably installed in the guide groove through a guide rib; a vertically arranged and internally hollow blow pipe is fixed at the bottom of the guide groove, an air inlet and a blowout opening are sequentially formed at the top end and the bottom side of the blow pipe, and an avoiding cavity is formed at the bottom of the gate plate and is located on the same axis as the blow pipe and is closed at the top; when the gate plate is lowered to close the valve body, the air pressure in the avoiding cavity is gradually compressed by the blow pipe and then enters the blow pipe from the air inlet, at this time, the liquid in the blow pipe is forced to be high-speedly discharged from the blowout opening under the action of atmospheric pressure, and then the impurities in the guide groove are partially or totally blown out. The problems that the guide groove of the traditional gate valve is prone to silt accumulation, the frequency of manual cleaning is high, and operation and maintenance are complicated are solved, the gate valve opening and closing process is automatically washed and cleaned, and the frequency of manual maintenance is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of pipeline valve technology, specifically to a low-frequency cleaning and maintenance type pipeline gate valve. Background Technology

[0002] In existing low-pressure pipeline networks for chemical water supply and drainage, municipal rainwater collection, and sewage transportation, gate valves have become the most widely used core valves due to their advantages such as straight flow path, low fluid resistance, non-directional opening and closing, stable sealing performance, and suitability for large-diameter pipeline transportation conditions. The basic structure of a conventional gate valve mainly consists of a valve body, valve cover, valve stem, operating handwheel, and gate. A recessed guide groove is set at the bottom of the internal chamber of the valve body, and the gate slides vertically within the guide groove. The guide groove enables vertical opening and closing guidance and horizontal limiting positioning, ensuring no deviation during the gate's opening and closing process and precise sealing. This is the core guiding structure for the stable operation of the gate valve.

[0003] The media transported by municipal rainwater and sewage pipe networks have a complex composition, containing a large amount of suspended solids, silt, fine sand, gravel, and other solid sediments. These impurities are characterized by high content, rapid sedimentation, and large accumulation. Under conditions such as low-speed transport, pipe network pressure stabilization shutdown, and rainwater settling, the silt and heavy impurities in the media will continue to settle under gravity, eventually accumulating inside the recessed guide groove at the bottom of the valve body. When the accumulation of silt and impurities in the guide groove is excessive, it directly hinders the vertical closing stroke of the gate valve, causing problems such as the gate valve not being able to fully close, gate valve jamming, and poor sealing. To ensure the normal opening and closing and sealing performance of the gate valve, the existing conventional solution is to install an independent drain bolt at the bottom of the valve body. Maintenance personnel need to periodically shut down the pipe network, drain the pipe media, and manually remove the drain bolt to clean the accumulated impurities in the guide groove.

[0004] However, in actual engineering operation and maintenance, the impurity content of rainwater and sewage media is extremely high, and the frequency of manual cleaning of conventional gate valves is extremely high. Some low-lying pipe networks and old sewage pipe networks need to be cleaned weekly or even daily, resulting in a large workload and high labor costs. At the same time, frequent disassembly and assembly of sewage and pipe network start-up and shutdown operations will aggravate the wear of valve body threads and aging of flange seals, significantly shortening the service life of valves. It is impossible to solve the problem of sludge accumulation in the guide groove from the root cause. Frequent maintenance operations will also interrupt the normal water supply and sewage discharge of the pipe network, affecting the continuity of municipal drainage and water conservancy scheduling, resulting in low efficiency of pipe network operation and maintenance. Summary of the Invention

[0005] The purpose of this invention is to provide a low-frequency cleaning and maintenance type pipeline gate valve to solve the problems of easy siltation in the guide groove of traditional gate valves, high frequency of manual cleaning, and cumbersome operation and maintenance. This invention enables automatic flushing and sludge removal during the opening and closing process of the gate valve, significantly reducing the frequency of manual maintenance and improving the stability of valve operation.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A low-frequency cleaning and maintenance type pipeline gate valve includes a valve body with a recessed guide groove in the inner cavity cross-section. A gate that can move up and down to open or close the valve body is slidably installed in the guide groove via guide ribs. The core improvement is that a vertically arranged and hollow blowpipe is fixed at the bottom of the guide groove. An air inlet and a flushing outlet are sequentially opened at the top and bottom of the blowpipe. A clearance cavity with the same axis as the blowpipe and closed at the top is opened at the bottom of the gate. When the gate moves down to close the valve body, the air pressure in the clearance cavity is gradually compressed by the air pipe and enters the blowpipe through the air inlet. At this time, under the downward pressure of atmospheric pressure, the liquid in the blowpipe is rushed out at high speed from the flushing outlet, and then the impurities in the guide groove are partially or completely blown out.

[0007] By adopting the above solution and adding a pneumatic coordination structure between the hollow blowpipe and the bottom clearance cavity of the gate valve, no external air source or manual operation is required. The mechanical stroke of the gate valve's own closure is used to achieve pneumatic energy storage and high-pressure flushing. During the downward closing process of the gate valve, the clearance cavity and the blowpipe form a sealed compression space. High-pressure fluid is generated through pneumatic compression and is sprayed at high speed from the bottom flushing port to directionally flush the silt and impurities accumulated at the bottom of the guide groove. This achieves automatic slag removal every time the valve closes, reducing the amount of impurities accumulated at the source and significantly reducing the frequency of manual periodic cleaning. This solves the core problems of traditional gate valves, such as slag accumulation in the guide groove, jamming during opening and closing, and frequent maintenance. It is suitable for long-term stable operation of high-impurity rainwater and sewage media.

[0008] As a preferred embodiment of a low-frequency cleaning and maintenance type pipeline gate valve, the opening diameter of the flushing port is larger than that of the main flushing port. By setting a diameter difference structure with a small air inlet and a large flushing port, gas can quickly enter the blow pipe and accumulate and pressurize, forming a high-pressure airflow and a medium-mixed fluid in a closed space, thereby increasing the fluid jet impact force and improving the flushing, stripping and discharge effect on impurities in the guide groove.

[0009] As a preferred embodiment of a low-frequency cleaning and maintenance type pipeline gate valve, the flushing port is an elongated port with multiple ports, all located near the bottom of the guide groove and arranged in a circumferential array along the bottom side of the blowpipe. Compared to a single-hole structure, this elongated multi-hole array structure enables 360° circumferential full-coverage jet flushing, precisely targeting all siltation areas at the bottom of the guide groove without any blind spots. The elongated hole structure increases the fluid jet coverage, and the multiple flushing ports in the array can simultaneously spray high-pressure fluid, impacting and dispersing the accumulated silt and clumps of impurities in the guide groove from all directions, resulting in a uniform and thorough cleaning effect and further reducing the need for manual maintenance.

[0010] As a preferred embodiment of a low-frequency cleaning and maintenance type pipeline gate valve, the outer wall of the blow pipe and the inner wall of the clearance cavity are interference fit. The interference fit can ensure that the clearance cavity and the outer wall of the blow pipe are completely sealed during the downward movement of the gate, eliminating the problem of air pressure leakage, ensuring that the air pressure in the cavity continues to rise and the pressure is stable during the compression process, and ensuring sufficient power for high-pressure flushing.

[0011] As a preferred embodiment of a low-frequency cleaning and maintenance type pipeline gate valve, a drain nut is installed at the bottom of the guide groove via a threaded detachable type. This drain nut is coaxially and fixedly connected to the bottom end of the blow-off pipe. The threaded detachable drain nut enables quick disassembly, inspection, and replacement of the blow-off pipe. When the blow-off port becomes blocked or the blow-off pipe ages and is damaged, the drain nut can be directly removed to replace the parts without disassembling the entire valve body, making inspection and maintenance convenient and cost-effective. At the same time, the drain nut can seal the bottom end of the blow-off pipe to ensure the air pressure compression is tight, balancing the conventional automatic flushing function with the convenience of later inspection and maintenance.

[0012] As a preferred embodiment of a low-frequency cleaning and maintenance type pipeline gate valve, two support screws are threadedly installed at the bottom of the guide groove, penetrating into the valve body and symmetrically distributed on the left and right sides of the drain nut. Two sets of support platforms are provided at the bottom of the gate plate to cooperate with the support screws. The lowest point of the support platform should be higher than or equal to the highest point of the flushing port. The symmetrically arranged support screws, in cooperation with the support platforms at the bottom of the gate plate, provide vertical support for the fully closed gate plate, ensuring that the flushing port is always exposed and not obstructed by the gate plate. This ensures stable and effective flushing function with each closure, guaranteeing the structural stability of the equipment during long-term operation.

[0013] As a preferred embodiment of a low-frequency cleaning and maintenance type pipeline gate valve, the support screw is also fitted with a set nut located outside the valve body and firmly secured thereto. The set nut can lock and position the support screw to prevent it from loosening or shifting during pipeline medium impact and long-term valve opening and closing vibration, thus ensuring the stability of the support structure. At the same time, the screw height can be finely adjusted according to the actual working conditions to adapt to different gate closure strokes, thereby improving structural adaptability and equipment operational reliability.

[0014] As a preferred embodiment of a low-frequency cleaning and maintenance-oriented pipeline gate valve, positioning flanges are coaxially fixed to the front and rear sides of the valve body for sealing connection with the pipeline. A valve cover is also bolted and fixed to the top of the valve body. A valve stem, threaded onto the top of the valve cover, extends vertically into the valve body and drives the gate to move up and down. The positioning flanges ensure a coaxial and sealed connection between the valve body and the external pipeline, providing precise installation positioning, good sealing performance, and compatibility with conventional pipeline installation standards. The bolt-removable valve cover facilitates inspection, cleaning, and maintenance of the internal structure of the valve body. The threaded valve stem enables stable vertical lifting and lowering transmission, precisely driving the gate to complete the opening and closing action.

[0015] As a preferred embodiment of a low-frequency cleaning and maintenance type pipeline gate valve, a non-slip handwheel is coaxially fixed at the top of the valve stem. The non-slip handwheel can increase the grip friction of the operator, making it less prone to slippage during opening and closing operations, improving the safety and convenience of manual operation, and making operation labor-saving and highly practical.

[0016] As a preferred embodiment of a low-frequency cleaning and maintenance type pipeline gate valve, the bottom end of the valve stem is further rotatably connected to a T-shaped groove on the top of the gate through a T-shaped head fixed thereto. The plug-in rotatable connection structure of the T-shaped head and the T-shaped groove can realize the efficient conversion of the valve stem rotational motion to the vertical linear motion of the gate, with stable transmission and no jamming; at the same time, a slight rotation gap is reserved, which allows the gate to self-adjust and finely adjust its alignment, ensuring precise sealing between the gate and the valve seat, improving the valve sealing performance, and the structure is wear-resistant and has a long service life.

[0017] The beneficial effects of this invention are: 1. Automatic sludge removal, significantly reducing maintenance frequency: Utilizing the gate valve's own closing mechanical stroke, through the air pressure compression structure of the avoidance chamber and the blow-off pipe, the valve automatically flushes the accumulated impurities in the guide groove with high pressure every time it closes, eliminating the need for frequent manual shutdowns for cleaning. This solves the problems of severe sludge accumulation, high maintenance frequency, and large workload of traditional gate valves when used with rainwater and sewage media. The frequency of manual cleaning and maintenance is greatly reduced, significantly saving on pipeline maintenance labor and time costs. 2. Thorough cleaning with no dead corners: The circumferential array of long strip flushing outlets, combined with the pressure difference boosting design of different diameters, achieves 360° full coverage high-pressure flushing of the bottom of the guide groove, which can effectively peel off and blow away the clumps of impurities in dead corners, greatly improving the valve's operational stability and service life. 3. Stable structure and strong protection: The interference fit between the blow pipe and the clearance cavity ensures air pressure compression sealing and sufficient flushing power; the symmetrical support screw and limiting structure can effectively protect the blow pipe structure and avoid extrusion deformation and functional failure. The set nut can prevent the structure from loosening. The equipment has high long-term operational stability and is suitable for complex pipeline network conditions such as outdoor, humid and impurity-rich environments. 4. Convenient maintenance and high versatility: The blow-off pipe adopts a threaded detachable sewage nut installation structure, which makes it convenient to disassemble, repair and replace accessories without disassembling the valve body, thus reducing equipment maintenance costs; the whole body retains the flange installation and manual opening and closing structure of the traditional gate valve, which is fully compatible with existing municipal, chemical and water conservancy pipeline systems, with strong versatility and low modification difficulty. 5. No additional energy consumption required, energy-saving and environmentally friendly: The entire automatic slag removal process is completed by the mechanical power of valve opening and closing. No external power supply, air supply or other auxiliary equipment are required. There is no additional energy consumption. The structure is simple, energy-saving and environmentally friendly, and the operating cost is extremely low. It is suitable for large-scale pipeline network application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A 3D structural diagram of a low-frequency cleaning and maintenance type pipeline gate valve; Figure 2 This is a front view of a low-frequency cleaning and maintenance type pipeline gate valve; Figure 3 Right view of a low-frequency cleaning and maintenance type pipeline gate valve; Figure 4 A bottom view of a low-frequency cleaning and maintenance type pipeline gate valve; Figure 5 To display along the valve body axial direction Figure 1 A three-dimensional structural diagram of the internal structure; Figure 6 for Figure 5 A magnified view of a section at point A in the middle; Figure 7 for Figure 5 Plan view of the middle gate when it is closed; Figure 8 for Figure 5 Plan view of the middle gate when it is open; Figure 9 To display along the circumference of the valve body Figure 1 A three-dimensional structural diagram of the internal structure; Figure 10 for Figure 9 A magnified view of a section at point B in the middle; Figure 11 for Figure 9 Plan view of the middle gate when it is closed; Figure 12 for Figure 9 Plan view of the middle gate when it is open.

[0020] The markings in the diagram are: 1. Valve body; 2. Guide groove; 3. Gate; 4. Blow pipe; 5. Air inlet; 6. Sewage outlet; 7. Reflux cavity; 8. Drain nut; 9. Support screw; 10. Support platform; 11. Set nut; 12. Positioning flange; 13. Valve cover; 14. Valve stem; 15. Handwheel; 16. T-head; 17. T-slot; 18. Guide rib. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figures 1 to 5 , Figure 9 As shown, a low-frequency cleaning and maintenance type pipeline gate valve is provided, mainly used in low-pressure pipeline network systems such as chemical water supply and drainage, municipal rainwater collection, and sewage transportation. Specifically, it includes a valve body 1, with a recessed guide groove 2 opened in the inner cavity cross section of the valve body 1. A gate 3, which can move up and down to open or close the valve body 1, is slidably installed in the guide groove 2 through guide ribs 18. Positioning flanges 12, which are coaxially fixed to the front and rear sides of the valve body 1 and are sealed to the pipeline, are distributed. A valve cover 13 is also fixed to the top of the valve body 1 by bolts. A valve stem 14, which extends vertically into the valve body 1 and drives the gate 3 to move up and down, is installed on the top of the valve cover 13 by threads. An anti-slip handwheel 15 is coaxially fixed to the top of the valve stem 14. The bottom end of the valve stem 14 is further rotatably connected to the T-shaped groove 17 opened on the top of the gate 3 through a T-shaped head 16 fixed to it.

[0023] like Figures 5 to 12 As shown, a vertically arranged and hollow blowpipe 4 is fixed at the bottom of the guide groove 2. An air inlet 5 and a flushing port 6 are sequentially opened at the top and bottom of the blowpipe 4. A clearance cavity 7 located on the same axis as the blowpipe 4 and closed at the top is opened at the bottom of the gate plate 3. When the gate plate 3 moves down to close the valve body 1, the air pressure in the clearance cavity 7 is gradually compressed by the blowpipe and enters the blowpipe 4 from the air inlet 5. At this time, under the downward pressure of atmospheric pressure, the liquid in the blowpipe 4 is rushed out at high speed from the flushing port 6, and then the impurities in the guide groove 2 are partially or completely blown out. By adding a hollow blow pipe 4 and a pneumatically coordinated structure with the bottom clearance cavity 7 of the gate 3, no external air source or manual operation is required. The mechanical stroke of the gate valve's own closure is used to achieve pneumatic energy storage and high-pressure flushing. During the downward closing process of the gate 3, the clearance cavity 7 and the blow pipe 4 form a sealed compression space. High-pressure fluid is generated through pneumatic compression and is sprayed at high speed from the bottom flushing port 6 to directionally flush the mud and impurities accumulated at the bottom of the guide groove 2. This achieves automatic slag removal every time the valve closes, reducing the amount of impurities accumulated at the source and significantly reducing the frequency of manual cleaning. This solves the core problems of slag accumulation, opening and closing jamming, and frequent maintenance in traditional gate valves, and is suitable for long-term stable operation of high-impurity rainwater and sewage media.

[0024] Continue as Figures 5 to 12As shown, the opening diameter of the flushing port 6 is larger than that of the flushing port 6. By setting a diameter difference structure of small diameter air inlet 5 and large diameter flushing port 6, the gas can quickly enter the inside of the blow pipe 4 and accumulate and pressurize, forming a high-pressure airflow and medium mixed fluid in the closed space, so as to increase the impact force of fluid jet and improve the flushing, stripping and discharge effect of impurities in the guide groove 2.

[0025] Continue as Figures 5 to 12 As shown, the flushing port 6 is a long, narrow opening with four ports. All flushing ports 6 are located near the bottom of the guide channel 2 and are arranged in a circumferential array along the bottom side of the blowpipe 4. Compared to a single-hole structure, the long, narrow, multi-hole array structure can achieve 360° circumferential full-coverage jet flushing, precisely targeting all siltation areas at the bottom of the guide channel 2 without any dead corners. The long, narrow hole structure can increase the fluid jet coverage area, and the multiple flushing ports 6 arranged in the array can simultaneously spray high-pressure fluid, impacting and blowing away the silt and clumps of impurities accumulated in the guide channel 2 from all directions, resulting in a uniform and thorough cleaning effect and further reducing the need for manual maintenance.

[0026] Continue as Figures 5 to 12 As shown, the outer wall of the blow pipe 4 and the inner wall of the clearance cavity 7 are interference fit. The interference fit can ensure that the clearance cavity 7 and the outer wall of the blow pipe 4 are completely sealed during the downward movement of the gate 3, eliminating the problem of air pressure leakage, ensuring that the air pressure in the cavity continues to rise and the pressure is stable during the compression process, and ensuring sufficient power for high-pressure flushing.

[0027] like Figure 6 , Figure 10 As shown, a drain nut 8 is also installed at the bottom of the guide groove 2 via a threaded detachable type. The drain nut 8 is coaxially fixedly connected to the bottom end of the blow-off pipe 4. The threaded detachable drain nut 8 enables quick disassembly, maintenance, and replacement of the blow-off pipe 4. When the blow-off port is blocked or the blow-off pipe 4 is aged and damaged, the drain nut 8 can be directly removed to replace the parts without disassembling the entire valve body 1, making maintenance convenient and cost-effective. At the same time, the drain nut 8 can seal the bottom end of the blow-off pipe 4 to ensure the air pressure compression is airtight, taking into account both the conventional automatic flushing function and the convenience of later maintenance.

[0028] like Figure 10 As shown, two support screws 9, threaded through the valve body 1 and symmetrically distributed on the left and right sides of the drain nut 8, are also installed at the bottom of the guide groove 2. Two sets of support platforms 10, which cooperate with the support screws 9, are provided at the bottom of the gate 3. The lowest position of the support platform 10 should be higher than or equal to the highest position of the flushing port 6. The symmetrically arranged support screws 9, in cooperation with the support platforms 10 at the bottom of the gate 3, can provide vertical support for the fully closed gate 3, ensuring that the flushing port 6 is always in an exposed working state and will not be obstructed by the gate 3. This ensures the stable and effective flushing function with each closure and guarantees the structural stability of the equipment during long-term operation.

[0029] Continue as Figure 10 As shown, the support screw 9 is also fitted with a set nut 11 located outside the valve body 1 and firmly secured thereto. The set nut 11 can lock and position the support screw 9 to prevent the screw from loosening or shifting during pipeline medium impact and long-term valve opening and closing vibration, thus ensuring the stability of the support structure. At the same time, the screw height can be finely adjusted according to the actual working conditions to adapt to different gate 3 closing strokes, thereby improving the structural adaptability and equipment operation reliability.

[0030] like Figures 1 to 12 As shown, this low-frequency cleaning and maintenance type pipeline gate valve, based on the conventional gate valve opening and closing structure, adds an automatic pneumatic flushing structure. The overall operation is divided into two core working conditions: valve opening and automatic sludge removal when the valve is closed. The specific operation process is as follows: Valve opening condition: The operator turns the top anti-slip handwheel 15, which drives the valve stem 14 to rotate and rise. Through the transmission cooperation between the bottom T-shaped head 16 and the T-shaped groove 17, the gate 3 is lifted and moves vertically upward along the guide groove 2. The clearance cavity 7 at the bottom of the gate 3 moves upward synchronously with the gate 3 and gradually separates from the blow pipe 4. The flow channel of the valve body 1 is fully open, and the pipeline medium flows normally. There is no flushing action in this process, and it does not affect the normal water supply and sewage discharge of the pipeline. Valve closing and automatic slag removal operation: When the pipeline needs to be closed, turn the handwheel 15 in the reverse direction. The valve stem 14 drives the gate 3 to move vertically downward along the guide groove 2. The clearance cavity 7, which is closed at the bottom and top of the gate 3, is gradually fitted onto the outside of the blow pipe 4 and forms a sealed cavity through interference fit. As the gate 3 continues to move downward, the internal space of the clearance cavity 7 is continuously compressed, and the air in the cavity is compressed and pressurized. The high-pressure gas quickly enters the hollow blow pipe 4 through the air inlet 5 at the top of the blow pipe 4. High-pressure slag flushing operation: The air pressure inside the blow pipe 4 continues to rise. Under the action of atmospheric pressure difference, the medium inside the pipe mixes with the high-pressure gas to form a high-speed fluid, which is sprayed out at high speed from the long strip-shaped slag flushing ports 6 arranged in a circumferential array on the bottom side of the blow pipe 4. This precisely flushes the mud, sand and clumps of dirt accumulated at the bottom of the guide groove 2, blowing all or part of the impurities away from the guide groove 2, thus achieving automatic slag removal. Limit protection condition: When the gate 3 moves down to the closed limit position, the bottom support platform 10 and the support screw 9 cooperate to limit the movement, preventing the gate 3 from being pressed down too much and damaging the blow pipe 4, ensuring that the flushing port 6 is always exposed and effective, and ensuring that stable cleaning operation can be completed with each closing action; after long-term use, the blow pipe 4 can be dredged, repaired or replaced by disassembling the bottom drain nut 8, making maintenance convenient.

[0031] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-frequency cleaning and maintenance type pipeline gate valve, comprising a valve body, wherein a recessed guide groove is formed in the cross-section of the inner cavity of the valve body, and a gate plate capable of moving up and down to open or close the valve body is slidably installed in the guide groove via guide ribs; characterized in that: A vertically arranged, hollow blowpipe is fixed at the bottom of the guide groove. An air inlet and a flushing outlet are sequentially opened at the top and bottom of the blowpipe. A clearance cavity with the same axis as the blowpipe and closed at the top is opened at the bottom of the gate. When the gate moves down to close the valve body, the air pressure in the clearance cavity is gradually compressed by the blowpipe and enters the blowpipe through the air inlet. At this time, under the downward pressure of atmospheric pressure, the liquid in the blowpipe is rushed out at high speed from the flushing outlet, and then the impurities in the guide groove are partially or completely blown out.

2. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 1, characterized in that: The diameter of the flushing outlet is larger than that of the main flushing outlet.

3. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 1, characterized in that: The flushing ports are elongated and there are multiple ports. All flushing ports are located near the bottom of the guide groove and are arranged in a circumferential array along the bottom side of the blow pipe.

4. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 1, characterized in that: The outer wall of the blowpipe and the inner wall of the clearance cavity are interference fit.

5. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 1, characterized in that: A drain nut is also installed at the bottom of the guide groove via a threaded detachment mechanism. This drain nut is coaxially and fixedly connected to the bottom end of the blow pipe.

6. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 5, characterized in that: Two support screws are threaded into the valve body and symmetrically distributed on the left and right sides of the drain nut at the bottom of the guide groove. Two sets of support platforms are provided at the bottom of the gate plate to cooperate with the support screws. The lowest position of the support platform should be higher than or equal to the highest position of the drain port.

7. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 6, characterized in that: The support screw is also fitted with a set nut located outside the valve body and firmly securing it.

8. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 1, characterized in that: Positioning flanges that are coaxially fixed to the front and rear sides of the valve body and sealed to the pipeline are distributed. A valve cover is also fixed to the top of the valve body by bolts. A valve stem that extends vertically into the valve body and drives the gate to move up and down is installed on the top of the valve cover by threads.

9. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 8, characterized in that: A non-slip handwheel is coaxially fixed at the top of the valve stem.

10. The low-frequency cleaning and maintenance type pipeline gate valve according to claim 8, characterized in that: The bottom end of the valve stem is further rotatably connected to a T-shaped groove on the top of the gate via a T-shaped head fixed thereto.

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