Pressure release valve for airport apron well lid

Abstract

The utility model relates to the technical field of well lid breather valves, and discloses a pressure release valve for an airport apron well lid, which is characterized in that a spring is fixedly arranged at the bottom of the inner side of an external thread steel sleeve, a lower breather plug is arranged at the upper end of the spring, O rings are arranged on the outer surface of the lower breather plug, and a waterproof breathable film is arranged at the upper end of the lower breather plug; an upper breathing plug is arranged at the upper end of the waterproof breathable film, a filter screen is arranged at the upper end of the upper breathing plug, a moving rod is slidably arranged in the well lid sliding groove, a clamping block is arranged at one end of the moving rod, a fixing plate sleeves the end, away from the clamping block, of the moving rod, and a first reset spring fixed between the clamping block and the fixing plate sleeves the moving rod; the ventilation core structure has waterproof and ventilation functions, liquid sealing performance is ensured while air pressure inside and outside a well body is balanced, meanwhile, the filter screen effectively filters impurities of water entering the ventilation core, the structure failure risk is remarkably reduced, the maintenance frequency is reduced, and the ventilation core structure is particularly suitable for harsh environments such as airports and the like which are difficult to overhaul frequently.

Description

Technical Field

[0001] This utility model relates to the field of manhole cover breathing valve technology, specifically a pressure relief valve for apron manhole covers. Background Technology

[0002] The shafts beneath the airport apron serve as integrated carriers for various facilities such as fuel pipelines, water supply and drainage pipes, and cables. During operation, their internal pressure fluctuates significantly due to factors such as temperature fluctuations, dynamic changes in pipeline fluids, and equipment operation. Once the pressure exceeds the limit, it can easily lead to serious safety accidents such as damage to the shaft structure, pipeline rupture, or even fuel leaks, posing a major threat to airport operational safety and the lives and property of personnel.

[0003] Due to temperature differences and airflow variations between the inside and outside of manhole covers, a significant pressure difference easily forms between the internal and external air pressure. When the internal pressure is significantly lower than the external pressure, the manhole cover is firmly held onto the seat by the negative pressure, making it difficult to open. Conversely, when the internal pressure is too high, the manhole cover risks being lifted or even blown away, seriously affecting the safe operation of aircraft on the apron. Traditional breather valves lack effective filtration devices, and the venting core structure is prone to clogging, significantly increasing the probability of structural failure and the frequency of maintenance and repair. Based on this background, designing a pressure relief valve for apron manhole covers can effectively solve the problems of pressure imbalance between the inside and outside of the manhole and the easy clogging of the venting core structure, which has significant practical implications for the operational safety of aircraft on the apron. Utility Model Content

[0004] The purpose of this invention is to provide a pressure relief valve for apron manhole covers, solving the following technical problems: Due to temperature differences and air velocity variations inside and outside the manhole box, a significant pressure difference easily forms between the internal and external air pressure. When the internal air pressure is significantly lower than the external pressure, the manhole cover will be firmly adhered to the seat by the negative pressure, making it difficult to open; while when the internal air pressure is too high, the manhole cover is at risk of being lifted or even blown away, seriously affecting the safe operation of aircraft on the apron. Traditional breather valves lack effective filtering devices, and the venting core structure is prone to blockage, which not only significantly increases the probability of structural failure but also significantly increases the frequency of maintenance and repair.

[0005] The objective of this utility model can be achieved through the following technical solution: a pressure relief valve for apron manhole covers, comprising an externally threaded steel sleeve, a spring fixedly installed at the bottom of the inner side of the externally threaded steel sleeve, a lower breathing plug installed at the upper end of the spring, an O-ring installed on the outer surface of the lower breathing plug, the O-ring being tightly fitted to the inner wall of the externally threaded steel sleeve, a waterproof and breathable membrane installed at the upper end of the lower breathing plug, an upper breathing plug installed at the upper end of the waterproof and breathable membrane, and a filter assembly installed at the upper end of the upper breathing plug, the filter assembly being used to filter water entering the breathable core.

[0006] As a further embodiment of this utility model: a sealing ring is provided between the upper end of the upper breathing plug and the well cover.

[0007] As a further embodiment of this invention: both the upper and lower breathing plugs allow air and water to pass through, while the waterproof and breathable membrane only allows air to pass through.

[0008] As a further embodiment of this utility model: the filter assembly includes a filter screen disposed at the upper end of the upper breathing plug, the two ends of the filter screen are provided with limiting components, and a sealing gasket is provided between the filter screen and the manhole cover.

[0009] As a further embodiment of this utility model: the limiting component includes a movable rod slidably disposed in the sliding groove of the manhole cover, one end of the movable rod is provided with a locking block, the end of the movable rod away from the locking block is sleeved with a fixing plate, the outer surface of the movable rod is provided with a lever extending to the upper end of the manhole cover, and a first return spring is sleeved on the movable rod and fixed between the locking block and the fixing plate.

[0010] As a further embodiment of this utility model: the two ends of the filter screen are symmetrically provided with slots that match the card blocks.

[0011] As a further embodiment of this utility model, a second reset spring is symmetrically arranged at both ends of the filter screen.

[0012] As a further aspect of this utility model: the working pressure of the spring is greater than the force generated by the pressure difference on the corresponding area of ​​the ventilated core.

[0013] The beneficial effects of this utility model are:

[0014] (1) This utility model uses a waterproof and breathable device and upper and lower breathing valves to work together to balance the air pressure inside and outside the well box, effectively avoiding the risks of the well cover being sucked tight and difficult to open, or being blown away due to the air pressure difference. It provides a solid guarantee for the stable operation of well equipment and the safe take-off and landing of aircraft on the apron. When the well box air pressure exceeds the external air pressure threshold, the upper breathing valve can automatically push out the water in the upper breathing plug when the well box air pressure exceeds the external air pressure threshold. It can quickly open the air path, eliminate the pressure difference, and prevent the well cover from being pushed up due to the high pressure inside the box, making it difficult to open the well. By separating the O-ring on the upper breathing plug from the external threaded steel sleeve, the breathing valve can be quickly opened, which is convenient for the inspection and maintenance of the inside of the well cover. The product has significant advantages such as stable structure, convenient operation, and strong waterproof and breathable performance.

[0015] (2) This utility model filters water entering the breathable core structure by setting a filter screen. The lever drives the moving rod to move backward, releasing the limit of the card block and the card slot. The second reset spring drives the filter screen to move upward, which can quickly complete the cleaning or replacement of the filter screen, thereby effectively avoiding the blockage of the waterproof and breathable device, reducing the probability of structural failure, reducing maintenance needs, and is suitable for scenarios such as aprons where frequent maintenance is not advisable.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1 This is a cross-sectional structural diagram of the entire utility model;

[0019] Figure 2 This is a schematic diagram of the structure of the filter assembly of this utility model;

[0020] Figure 3 This is a structural schematic diagram of the installation position of the manhole cover and breather valve of this utility model.

[0021] In the diagram: 1. External threaded steel sleeve; 2. Spring; 3. Lower breathing plug; 4. O-ring; 5. Waterproof and breathable membrane; 6. Upper breathing plug; 7. Sealing ring; 8. Filter assembly; 81. Filter screen; 82. Limiting assembly; 821. Moving rod; 822. Locking block; 823. Fixing plate; 824. Toggle lever; 825. First return spring; 83. Second return spring. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0024] In the field of valve technology, when the air pressure inside the manhole box is too low compared to the outside air pressure, the manhole cover will be sucked onto the seat and difficult to open; when the air pressure inside the manhole box is too high compared to the outside air pressure, there is a risk that the manhole cover will be lifted and blown away. Therefore, the problem of air pressure balance between the inside and outside of the manhole has an important impact on the operational safety of aircraft on the tarmac. This utility model provides a pressure relief valve for tarmac manhole covers to solve the problem of air pressure balance and anti-clogging of tarmac manhole covers. It achieves air pressure balance between the inside and outside of the manhole through a series of innovative designs. The specific implementation method is as follows:

[0025] like Figure 1 , Figure 3 As shown, a pressure relief valve for apron manhole covers is disclosed. The breather valve is installed on the manhole cover and mainly consists of an upper breather plug 6, a waterproof and breathable membrane 5, a lower breather plug 3, an external threaded steel sleeve 1, a spring 2, and a sealing ring 7. The spring 2 is fixedly installed at the bottom of the inner side of the external threaded steel sleeve 1, and the lower breather plug 3 is installed at the upper end of the spring 2. The inner wall of the external threaded steel sleeve 1 is provided with a smooth sealing surface, and the outer surface of the lower breather plug 3 is provided with an O-ring 4. The O-ring 4 is tightly fitted with the smooth sealing surface of the inner wall of the external threaded steel sleeve 1 to ensure airtightness under normal conditions. The O-ring 4 on the outer surface of the lower breather plug 3 forms a dynamic seal with a specific area of ​​the inner wall of the steel sleeve. When the lower breather plug 3 moves downward, its O-ring disengages from the sealing surface of the inner wall of the external threaded steel sleeve 1, opening the air passage. The upper end of the lower breather plug 3 is provided with a waterproof and breathable membrane 5, and the upper end of the waterproof and breathable membrane 5 is provided with an upper breather plug 6.

[0026] The working pressure of spring 2 is greater than the force generated by the pressure difference of 101.3 kPa on the corresponding area of ​​the vent core, so as to prevent the vent core structure inside the steel sleeve from being pushed down when the external air pressure is greater than the air pressure inside the well box, thus preventing external water from flowing into the well box.

[0027] Both the upper breathing plug 6 and the lower breathing plug 3 allow air and water to pass through, while the waterproof and breathable membrane 5 only allows air to pass through. When there is no water accumulation in the upper breathing plug 6, the breathing valve can connect the air inside and outside the manhole box, reducing the pressure difference between the inside and outside. This achieves a balance between the pressure inside and outside the manhole box while ensuring a certain degree of liquid sealing. When there is water accumulation in the upper breathing plug 6, the pressure regulation mechanism of the breathing valve will be automatically activated. Once the air pressure inside the manhole box exceeds the outside air pressure due to factors such as gas accumulation and temperature changes, and the pressure difference reaches a preset critical threshold, the water accumulated in the upper breathing plug 6 will be pushed out by the air pressure inside the manhole, thereby opening the air passage between the inside and outside of the manhole box, reducing the pressure difference, and preventing the excessive air pressure inside the manhole box from lifting the manhole cover. If the manhole cover is lifted and blown away, it will seriously affect the operational safety of aircraft on the apron. The pressure balance inside and outside the manhole cover is of irreplaceable importance for ensuring the safety of apron operations and maintaining the order of air transport.

[0028] When the air pressure inside the well box is lower than the outside air pressure, the well cover will be sucked onto the seat ring and difficult to open. At this time, the staff needs to press the vent core downwards to disengage the O-ring on the lower breather plug from the steel sleeve. Under the action of the outside air pressure, the water accumulated in the upper breather plug 6 will be forced into the well box. At this time, the breather valve is opened, reducing the pressure difference between the inside and outside, making it easier for the staff to open the well cover.

[0029] A sealing ring 7 is provided between the upper end of the upper breathing plug 6 and the manhole cover. The sealing ring 7 fills the physical gap between the upper breathing plug 6 and the manhole cover, preventing rainwater, water accumulation or other external liquids from seeping into the manhole body through the gap (especially in the complex environment of the apron, water accumulation, oil stains, etc. may invade through the edge of the manhole cover).

[0030] In summary, when the upper breathing plug 6 is free of water, the breathing valve can directly connect the air inside and outside the well box, reducing the pressure difference between the inside and outside. When the upper breathing plug 6 is filled with water, the air pressure inside the well box is greater than the outside air pressure and reaches a certain level. The water inside the upper breathing plug 6 will be pushed out by the air pressure inside the well, opening the air passage between the inside and outside, reducing the pressure difference, and avoiding the risk of the well cover being blown off. When the air pressure inside the well box is less than the outside air pressure, the well cover is difficult to open. By pressing the filter assembly 8, the venting core is pushed downwards, and the O-ring on the upper breathing plug 6 is disengaged from the external threaded steel sleeve 1. The filtered water will be forced into the well box, and the breathing valve will be open, making it convenient for workers to open the well cover for maintenance and repair.

[0031] Example 2: Based on Example 1, as follows Figure 2 As shown, a filter assembly 8 is installed at the upper end of the upper breathing plug 6. The filter assembly 8 is used to filter the water entering the breathable core structure. The apron environment is complex, and there may be dust, mud, oil and other particulate matter around the manhole cover. If these impurities enter the breathing valve, they may clog the waterproof breathable membrane 5, the upper breathing plug 6 or the lower breathing plug 3, causing the air pressure regulation to fail. Impurities clog the breathable core structure, requiring frequent manual cleaning or replacement of the breathing valve. The filter assembly 8 can significantly reduce maintenance needs and is suitable for scenarios such as aprons where frequent maintenance is not advisable.

[0032] The filter assembly 8 includes a filter screen 81 disposed on the upper end of the upper breathing plug 6. Limiting components 82 are provided at both ends of the filter screen 81. The limiting components 82 are used to replace the filter screen 81 periodically. A sealing gasket is provided between the filter screen 81 and the manhole cover.

[0033] The manhole cover has symmetrical sliding grooves at both ends of the filter screen 81. The limiting assembly 82 includes a movable rod 821 symmetrically slidably disposed within the sliding groove of the manhole cover. One end of the movable rod 821 is provided with a locking block 822, and the end of the movable rod 821 away from the locking block 822 is sleeved with a fixing plate 823. The fixing plate 823 is fixedly connected to the sliding groove of the manhole cover. The movable rod 821 passes through the fixing plate 823 and has a limiting block at its end. The limiting block is used to limit the displacement of the movable rod 821 and prevent it from moving. Slide out of the fixed plate 823. The outer surface of the moving rod 821 is provided with a lever 824 extending to the upper end of the manhole cover. The upper end of the manhole cover is provided with a slot that communicates with the sliding groove. The lever 824 moves back and forth in the slot. The upper end of the lever 824 is provided with a groove. The groove makes it easy for the staff to manually move the lever 824 to quickly replace the filter screen 81. The moving rod 821 is fitted with a first return spring 825 that is fixed between the locking block 822 and the fixed plate 823.

[0034] The filter screen 81 has symmetrical slots at both ends that match the locking block 822, and the filter screen 81 is fixed by the locking block 822 and the locking slots.

[0035] The filter screen 81 is symmetrically provided with second return springs 83 at both ends. After the limiting component 82 is released, the second return springs 83 can quickly push the filter screen 81 out, making it easy to remove the filter screen 81. At the same time, when the air pressure inside the well box is lower than the outside air pressure and the well cover is difficult to open, after the limiting component 82 is released, the filter screen 81 can be pressed or the filter screen 81 can be removed and the upper breather plug 6 can be pressed. The O-ring on the upper breather plug 6 will disengage from the external threaded steel sleeve 1, and the filtered water will be forced into the well box. The breather valve will be opened, making it easy to open the well cover for internal maintenance and repair.

[0036] The bottom of the breathing valve is equipped with a pressure plate, and screws are installed at both ends of the pressure plate. The pressure plate is used to press it down to prevent it from falling off. The pressure plate is fixed with screws, which makes it easy to replace the device.

[0037] In summary, during use, the breather valve can be quickly replaced by installing screws and pressure plates. The apron environment is complex, and there may be dust, mud, oil, and other particulate matter around the manhole cover. Water entering the venting core is first filtered through the filter screen 81. The operator can periodically move the moving lever 824 to move the moving rod 821 backward, squeezing the first return spring 825 and removing the locking block 822 from the slot, thus releasing the restriction on the filter screen 81. At this time, the second return spring 83 moves the filter screen 81 upward, which can quickly clean or replace the filter screen 81. When the filtered water enters the venting core, the waterproof and breathable membrane 5 is not easily blocked, reducing the probability of structural failure and reducing maintenance requirements. It is suitable for scenarios such as aprons where frequent maintenance is difficult, while also ensuring the safety of aircraft operation on the apron.

[0038] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A pressure relief valve for apron manhole covers, characterized in that, The device includes an externally threaded steel sleeve (1), a spring (2) fixedly installed at the bottom of the inner side of the externally threaded steel sleeve (1), a lower breathing plug (3) installed at the upper end of the spring (2), an O-ring (4) installed on the outer surface of the lower breathing plug (3), the O-ring (4) being tightly fitted to the inner wall of the externally threaded steel sleeve (1), a waterproof and breathable membrane (5) installed at the upper end of the lower breathing plug (3), an upper breathing plug (6) installed at the upper end of the waterproof and breathable membrane (5), and a filter assembly (8) installed at the upper end of the upper breathing plug (6). The filter assembly (8) is used to filter water entering the breathable core.

2. A pressure relief valve for apron manhole covers according to claim 1, characterized in that, A sealing ring (7) is provided between the upper end of the upper breathing plug (6) and the well cover.

3. A pressure relief valve for apron manhole covers according to claim 1, characterized in that, Both the upper breathing plug (6) and the lower breathing plug (3) allow air and water to pass through, while the waterproof and breathable membrane (5) only allows air to pass through.

4. A pressure relief valve for apron manhole covers according to claim 1, characterized in that, The filter assembly (8) includes a filter screen (81) disposed at the upper end of the upper breathing plug (6), with limit components (82) disposed at both ends of the filter screen (81), and a sealing gasket disposed between the filter screen (81) and the manhole cover.

5. A pressure relief valve for apron manhole covers according to claim 4, characterized in that, The limiting component (82) includes a movable rod (821) slidably disposed in the sliding groove of the manhole cover. One end of the movable rod (821) is provided with a locking block (822). The end of the movable rod (821) away from the locking block (822) is sleeved with a fixing plate (823). The outer surface of the movable rod (821) is provided with a lever (824) extending to the upper end of the manhole cover. A first return spring (825) is sleeved on the movable rod (821) and fixed between the locking block (822) and the fixing plate (823).

6. A pressure relief valve for apron manhole covers according to claim 4, characterized in that, The filter screen (81) has symmetrical slots at both ends that match the card block (822).

7. A pressure relief valve for apron manhole covers according to claim 4, characterized in that, The filter screen (81) is provided with second return springs (83) symmetrically arranged at both ends.

8. A pressure relief valve for apron manhole covers according to claim 1, characterized in that, The working pressure of the spring (2) is greater than the force generated by the pressure difference on the corresponding area of ​​the ventilated core.

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