Drainage device and fire-fighting water crane drainage system

Abstract

The invention relates to the field of drainage equipment of fire hydrants, in particular to a drainage device and a fire-fighting water crane drainage system. The drainage system is used for solving the problems that a drainage system of an existing fire-fighting water crane breaks down easily and operation is complex. The water drainage device comprises a valve body communicated with the main water supply pipeline, a valve element is movably installed in a valve cavity of the valve body in an up-down guiding mode, and an elastic piece providing upward acting force for the valve element is arranged between the valve body and the valve element so that the valve element can be located at a conduction position separated from the valve element matching face in the natural state. When high-pressure water exists in the main water supply pipeline, the high-pressure water impacts the valve element, the valve element is impacted to move downwards to a cut-off position attached to the matching face of the valve element, and when pressure in the main water supply pipeline is lost, the elastic piece overcomes water pressure to drive the valve element to reset. The connection position and the disconnection position of the valve element are controlled through the elastic force of the elastic piece and the acting force of water pressure impact, manual operation is not needed, and drainage is reliable and efficient.

Description

Technical Field

[0001] The invention relates to the field of water discharge equipment of fire hydrants, and in particular to a water discharge device and a fire fighting water crane drainage system. Background Art

[0002] Fire water crane is a common firefighting equipment, which plays a very important role in urban firefighting. When the water source stored in the fire truck is exhausted, water can be added at the fire water crane. The drainage of the fire water crane is very important. After the water filling work is completed, the residual water in the water pipe needs to be discharged in time, otherwise the pipe will freeze and crack in the low temperature environment, affecting the normal firefighting and rescue. In the prior art, an electromagnetic drain valve or a manual drain valve is usually installed on the pipeline of the fire water crane. The electromagnetic drain valve is prone to malfunction in a humid environment; the manual drain valve requires manual power to turn the drain switch, and repeatedly turning the switch will increase the risk of damage and maintenance, wasting manpower and time. Summary of the invention

[0003] The purpose of the present invention is to provide a water discharge device to solve the problem that the water discharge device of the existing fire water crane is prone to malfunction and complicated to operate; the purpose of the present invention is also to provide a fire water crane drainage system to solve the problem that the drainage system of the existing fire water crane is prone to malfunction and complicated to operate.

[0004] To solve the above technical problems, a water discharge device of the present invention includes a valve body, the upper end of the valve body is used to communicate with a main water supply pipeline, a valve core is movably installed in the valve cavity of the valve body with upper and lower guides, the valve cavity has a valve core mating surface that cooperates with the valve core, an elastic member that provides an upward force to the valve core is arranged between the valve body and the valve core, so that the valve core is in a high position separated from the valve core mating surface in a natural state, the valve core has an upward pressure-bearing surface, a water-blocking and pressure-boosting plate is provided above the valve core in the valve cavity, and a high-pressure water spray hole facing the pressure-bearing surface is provided on the water-blocking and pressure-boosting plate. When there is high-pressure water in the main water supply pipeline, the high-pressure water impacts the valve core through the high-pressure water spray hole, and the valve core is impacted to overcome the force of the elastic member and move downward until it is in the cut-off position that fits with the valve core mating surface. When the main water supply pipeline loses pressure, the elastic member overcomes the water pressure and drives the valve core to reset.

[0005] Furthermore, the valve core comprises a plate-shaped core body, and the pressure-bearing surface is an upper plate surface of the plate-shaped core body.

[0006] Furthermore, the valve cavity includes a funnel-shaped inner cavity, and the plate-shaped core body is located in the funnel-shaped inner cavity. When in the cut-off position, the outer edge surface of the plate-shaped core body is sealed and matched with the inner wall surface of the funnel-shaped inner cavity.

[0007] Furthermore, the valve chamber has a lower drainage chamber on the lower side of the funnel-shaped inner chamber, the funnel-shaped inner chamber is connected to the lower drainage chamber, the valve core includes a top support bottom located on the lower side of the plate-shaped core body, the elastic member is arranged in the lower drainage chamber and directly acts on the top support bottom of the valve core.

[0008] Furthermore, the valve core includes an upwardly extending straightening rod located on the upper part of the plate-shaped core body, and a straightening hole for the straightening rod to pass through is provided on the water-blocking and pressurizing plate. The cross-sectional size of the straightening rod is smaller than the cross-sectional size of the straightening hole so as to realize the straightening of the valve core when the guide movement of the valve core deviates.

[0009] Furthermore, the elastic member is an elastic airbag, and the bottom of the top support is disc-shaped.

[0010] Furthermore, the funnel-shaped inner cavity has a cavity bottom, and a leakage port connected to the lower drainage cavity is provided on the cavity bottom. The valve core guide is movably installed on the cavity bottom. An airbag protection mounting cover is fixedly connected to the lower side of the cavity bottom. The elastic airbag is installed in the airbag protection mounting cover, and the top support bottom of the valve core extends into the airbag protection mounting cover.

[0011] Furthermore, the airbag protective mounting cover includes a cover body and a base plate, the air nozzle of the elastic airbag passes downward through the base plate and is locked and fixed by a locking nut so that the elastic airbag is fixedly mounted on the base plate, and the base plate is detachably connected to the cover body.

[0012] Furthermore, a protective tube section surrounding the gas nozzle is provided on the lower side of the bottom plate, and a protective cover is threadedly connected to the bottom of the protective tube section.

[0013] The present invention proposes a new technical solution to the above technical problems: a valve body is installed on the main water supply pipeline, a valve core is installed in the valve cavity of the valve body in an upward and downward guiding manner, a valve core mating surface that cooperates with the valve core is provided in the valve cavity, and an elastic member that can provide an upward elastic force for the valve core is arranged at the bottom of the valve core. The high-pressure water in the main water supply pipeline impacts the valve core to move the valve core downward until it is in the cut-off position where it fits with the valve core mating surface, and the elastic member is used to push the valve core upward until it is in the conduction position separated from the valve core mating surface during the water pressure reduction stage in the main water supply pipeline, so that the accumulated water can flow out of the valve body through the valve core. The conduction position and the cut-off position of the valve core are controlled by the elastic force of the elastic member and the force of the water pressure impact, without manual operation, and the drainage is reliable and efficient.

[0014] Another aspect of the present invention provides a fire water crane drainage system, which includes a ground main structure and an underground main water supply pipeline, wherein a water inlet valve and a water discharge device are arranged on the main water supply pipeline, wherein the water discharge device includes a valve body, wherein the upper end of the valve body is used to communicate with the main water supply pipeline, and a valve core is movably installed in the valve cavity of the valve body in an upper and lower guiding manner, wherein the valve cavity has a valve core mating surface that cooperates with the valve core, and an elastic member that provides an upward force to the valve core is arranged between the valve body and the valve core, so that the valve core is in a high position separated from the valve core mating surface in a natural state, and the valve core has an upward pressure-bearing surface, and a water-blocking and pressure-boosting plate is arranged above the valve core in the valve cavity, and a high-pressure water spraying hole facing the pressure-bearing surface is arranged on the water-blocking and pressure-boosting plate. When there is high-pressure water in the main water supply pipeline, the high-pressure water impacts the valve core through the high-pressure water spraying hole, and the valve core is impacted to overcome the force of the elastic member and move downward until it is in a cut-off position that fits with the valve core mating surface, and when the main water supply pipeline loses pressure, the elastic member overcomes the water pressure to drive the valve core to reset.

[0015] Furthermore, the valve core comprises a plate-shaped core body, and the pressure-bearing surface is an upper plate surface of the plate-shaped core body.

[0016] Furthermore, the valve cavity includes a funnel-shaped inner cavity, and the plate-shaped core body is located in the funnel-shaped inner cavity. When in the cut-off position, the outer edge surface of the plate-shaped core body is sealed and matched with the inner wall surface of the funnel-shaped inner cavity.

[0017] Furthermore, the valve chamber has a lower drainage chamber on the lower side of the funnel-shaped inner chamber, the funnel-shaped inner chamber is connected to the lower drainage chamber, the valve core includes a top support bottom located on the lower side of the plate-shaped core body, the elastic member is arranged in the lower drainage chamber and directly acts on the top support bottom of the valve core.

[0018] Furthermore, the valve core includes an upwardly extending straightening rod located on the upper part of the plate-shaped core body, and a straightening hole for the straightening rod to pass through is provided on the water-blocking and pressurizing plate. The cross-sectional size of the straightening rod is smaller than the cross-sectional size of the straightening hole so as to realize the straightening of the valve core when the guide movement of the valve core deviates.

[0019] Furthermore, the elastic member is an elastic airbag, and the bottom of the top support is disc-shaped.

[0020] Furthermore, the funnel-shaped inner cavity has a cavity bottom, and a leakage port connected to the lower drainage cavity is provided on the cavity bottom. The valve core guide is movably installed on the cavity bottom. An airbag protection mounting cover is fixedly connected to the lower side of the cavity bottom. The elastic airbag is installed in the airbag protection mounting cover, and the top support bottom of the valve core extends into the airbag protection mounting cover.

[0021] Furthermore, the airbag protective mounting cover includes a cover body and a base plate, the air nozzle of the elastic airbag passes downward through the base plate and is locked and fixed by a locking nut so that the elastic airbag is fixedly mounted on the base plate, and the base plate is detachably connected to the cover body.

[0022] Furthermore, a protective tube section surrounding the gas nozzle is provided on the lower side of the bottom plate, and a protective cover is threadedly connected to the bottom of the protective tube section.

[0023] The present invention proposes a new technical solution to the above technical problems: a valve body is installed on the main water supply pipeline, a valve core is installed in the valve cavity of the valve body in an upward and downward guiding manner, a valve core mating surface that cooperates with the valve core is provided in the valve cavity, and an elastic member that can provide an upward elastic force for the valve core is arranged at the bottom of the valve core. The high-pressure water in the main water supply pipeline impacts the valve core to move the valve core downward until it is in the cut-off position where it fits with the valve core mating surface, and the elastic member is used to push the valve core upward until it is in the conduction position separated from the valve core mating surface during the water pressure reduction stage in the main water supply pipeline, so that the accumulated water can flow out of the valve body through the valve core. The conduction position and the cut-off position of the valve core are controlled by the elastic force of the elastic member and the force of the water pressure impact, without manual operation, and the drainage is reliable and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a drainage device of the present invention; Figure 2 It is a structural schematic diagram of a fire fighting water crane drainage system of the present invention.

[0025] In the figure: 1. threaded barrel section; 2. water-blocking booster plate; 3. upper shell; 4. connecting thread; 5. plate-shaped core; 6. fixing plate; 7. lower shell; 8. fixing pin; 9. top support bottom; 10. airbag protection mounting cover; 11. elastic airbag; 12. bottom plate; 13. locking nut; 14. bottom plate fixing pin; 15. air nozzle; 16. protective barrel section; 17. protective cover; 18. telescopic mechanism; 19. rotating mechanism; 20. water diversion and guide pipe; 21. sheath; 22. main water supply pipeline; 23. water inlet valve; 24. water discharge device; 25. fire hose interface; 26. outlet mounting thread. DETAILED DESCRIPTION

[0026] The present invention proposes a brand-new technical solution to the above-mentioned technical problems. The core concept of the present invention is: a valve body is installed on the main water supply pipeline, and a valve core is installed in the valve cavity of the valve body in an upward and downward guiding manner. The valve cavity has a valve core mating surface that cooperates with the valve core, and the lower part of the valve core is provided with an elastic member that can provide an upward elastic force for the valve core. The high-pressure water in the main water supply pipeline impacts the valve core to move the valve core downward until it is in the cut-off position where it fits with the valve core mating surface, and the elastic member is used to push the valve core upward in the stage of water pressure reduction in the main water supply pipeline until it is in the conduction position separated from the valve core mating surface, so that the accumulated water can flow out of the valve body. The elastic force of the elastic member and the force of the water pressure impact are used to control the conduction position and the cut-off position of the valve core, without the need for manual operation, and the drainage is reliable and efficient.

[0027] According to the above concept, a drain device of the present invention includes a valve body, the upper end of the valve body is used to communicate with the main water supply pipeline 22. Specifically, the upper end of the valve body has a threaded barrel section 1, which is screwed on the main water supply pipeline 22 through the threaded barrel section 1. A valve core is installed in the valve cavity of the valve body for upward and downward guiding movement. The valve cavity has a valve core matching surface that matches the valve core. An elastic member that provides an upward force to the valve core is arranged between the valve body and the valve core, so that the valve core is in a high conduction position separated from the valve core matching surface in a natural state. The valve core has an upward pressure-bearing surface, and the valve cavity is provided with a valve core above the valve core. Figure 1 The water-blocking and boosting plate 2 shown is installed on the step on the valve cavity by screws. The water-blocking and boosting plate 2 is provided with a high-pressure water spray hole facing the pressure-bearing surface. When there is high-pressure water in the main water supply pipeline 22, the high-pressure water impacts the valve core through the high-pressure water spray hole. The valve core overcomes the force of the elastic member under the impact and moves downward until it is in contact with the cut-off position of the matching surface of the valve core. When the main water supply pipeline 22 loses pressure, the elastic member overcomes the water pressure and drives the valve core to reset.

[0028] When using a fire-fighting water crane for firefighting, open the water inlet valve 23 on the main water supply pipeline 22, and water flows into the ground body through the main water supply pipeline 22. Since the main water supply pipeline 22 is connected to a water discharge device 24, the water flows through the high-pressure water spray port on the water-blocking booster plate 2 in the water discharge device 24 to impact the pressure-bearing surface of the valve core, so that the valve core overcomes the elastic force and moves downward. During this stage, the water can flow through the valve core and fall into the pool below; when the pressure in the main water supply pipeline 22 of the fire-fighting water crane increases to 0 When the pressure is above .1 MPa, the valve core and the valve core matching surface fit together to block the water flow; when the firefighting work is completed, the upstream water inlet valve 23 needs to be closed and the downstream valve needs to be opened. At this time, the water pressure of the main water supply pipeline 22 is reduced, and the elastic member provides an upward elastic force for the valve core to separate the valve core from the valve core matching surface. At this time, the accumulated water in the main water supply pipeline of the fire water crane and the main structure on the ground will flow through the valve core of the drainage device under the action of gravity and fall into the pool below, thus realizing the discharge of the accumulated water in the fire water crane. The elastic force of the elastic member and the force of the water pressure impact are used to control the conduction position and the cut-off position of the valve core. No manual operation is required, and the drainage is reliable and efficient.

[0029] In this embodiment, the valve core includes: Figure 1 The pressure-bearing surface of the plate-shaped core 5 shown is the upper plate surface of the plate-shaped core 5. The plate-shaped core 5 has a simple structure. In addition, in other embodiments, the valve core may also be block-shaped.

[0030] In this embodiment, the valve cavity includes a funnel-shaped inner cavity, and the plate-shaped core 5 is located in the funnel-shaped inner cavity. When in the cut-off position, the outer edge surface of the plate-shaped core 5 is sealed with the inner wall surface of the funnel-shaped inner cavity. Figure 1As shown, the inner cavity is funnel-shaped, and at this time, the outer edge surface of the plate-shaped core 5 also matches the shape of the inner cavity, that is, it is funnel-shaped. In another embodiment, the inner cavity can also be conical or trumpet-shaped, and the outer edge surface of the plate-shaped core is matched with the shape of the inner cavity, and it only needs to ensure that it cooperates reliably with the valve core. In another embodiment, the valve cavity can also be box-shaped, and a water hole for water flow to pass through is provided at the bottom. When in the cut-off position, the lower side of the plate-shaped core covers the water hole and is sealed with the water hole.

[0031] In this embodiment, the valve cavity has a lower drainage cavity at the lower side of the funnel-shaped inner cavity, the funnel-shaped inner cavity is connected with the lower drainage cavity, the valve core includes a top support bottom 9 at the lower side of the plate-shaped core 5, and the elastic member is arranged in the lower drainage cavity and directly acts on the top support bottom 9 of the valve core. In this way, the arrangement of the elastic member is convenient, and it is also ensured that the elastic member reliably applies an upward elastic force to the valve core. Of course, in another embodiment, the top support bottom may not be provided, and the elastic member directly acts on the bottom surface of the plate-shaped core 5. The lower end of the lower drainage cavity is provided with an outlet mounting thread 26, and is connected to a pipeline through the outlet mounting thread 26 to drain the accumulated water into the pool.

[0032] In this embodiment, the valve core includes a straightening rod extending upward on the upper part of the plate-shaped core body 5, and a straightening hole for the straightening rod to penetrate is provided on the water-blocking and pressure-boosting plate 2. The cross-sectional size of the straightening rod is smaller than the cross-sectional size of the straightening hole so as to realize the straightening of the valve core when the guided movement of the valve core deviates. In this way, the straightening rod can cooperate with the straightening hole to straighten the valve core when the deflection angle of the valve core is large, thereby ensuring the upward and downward guided movement of the valve core.

[0033] In this embodiment, the elastic member is an elastic airbag 11, and the top support bottom 9 is disc-shaped. The elastic airbag 11 has a simple structure and can reliably exert an upward elastic force on the valve core when it cooperates with the valve core. The disc-shaped top support bottom 9 ensures the uniformity of the force on the valve core. In addition, in another embodiment, the top support bottom can also be a plate-shaped structure of other shapes. In other embodiments, the elastic member can also be a compression spring, one end of which directly abuts against the bottom of the valve core to exert an upward elastic force on the valve core.

[0034] In this embodiment, the funnel-shaped inner cavity has a cavity bottom, and a water leakage port connected to the lower drainage cavity is provided on the cavity bottom. The valve core guide is movably installed on the cavity bottom. The lower side of the cavity bottom is fixedly connected with an airbag protection mounting cover 10, and the elastic airbag 11 is installed in the airbag protection mounting cover 10. The top support bottom 9 of the valve core extends into the airbag protection mounting cover 10. A fixing plate 6 is also installed on the lower side of the cavity bottom. The fixing plate 6 is arranged close to the lower side of the cut-off position of the plate-shaped core 5 to limit the downward movement of the plate-shaped core 5. The top of the airbag protection mounting cover 10 is installed on the fixing plate 6 through a fixing pin 8. The airbag protection mounting cover 10 can protect the elastic airbag 11 from the impact of the water flow when there is water flowing down in the drainage cavity, thereby extending the service life of the elastic airbag 11. Of course, in another embodiment, the elastic airbag 11 can also be cylindrical and installed on a bottom plate, and the upper end of the airbag is connected to the top support bottom. The valve body of this embodiment is divided into upper and lower petals in the upper area of ​​the conduction position of the valve core, and is divided into an upper shell 3 and a lower shell 7. The upper shell 3 and the lower shell 7 are connected by a connecting thread 4, thereby achieving convenience in replacement and maintenance.

[0035] In the present embodiment, the airbag protection mounting cover 10 includes a cover body and a base plate 12, the air nozzle 15 of the elastic airbag 11 passes downward through the base plate 12 and is locked and fixed by a locking nut 13, so that the elastic airbag 11 is fixedly mounted on the base plate 12, and the base plate 12 and the cover body are detachably connected by a base plate fixing pin 14. The detachable connection between the base plate 12 and the cover body makes the installation of the elastic airbag 11 easier. Installing the air nozzle 15 of the elastic airbag 11 on the base plate 12, on the one hand, facilitates the fixation of the elastic airbag 11, and on the other hand, prevents the air nozzle 15 thereon from affecting the elastic force of the elastic airbag 11 in the up and down directions in the airbag protection mounting cover 10. In addition, in other embodiments, the airbag protection mounting cover may also be drum-shaped as a whole, and a side door for loading the elastic airbag therein is provided on its side wall. In another embodiment, the air nozzle of the elastic airbag may also be installed on the side wall of the airbag protective cover; of course, the elastic airbag may also be directly placed in the airbag protective mounting cover without being fixed, as long as the elastic airbag can provide an upward elastic force for the valve core.

[0036] In this embodiment, a protective tube section 16 is provided on the lower side of the bottom plate 12 to enclose the air nozzle 15, and a protective cover 17 is threadedly connected to the bottom of the protective tube section 16. The protective tube section 16 can prevent damage to the air nozzle 15 and ensure the structural integrity of the elastic airbag 11. The protective cover 17 threadedly connected to the bottom of the protective tube section 16 can be unscrewed when the elastic airbag 11 needs to be maintained, saving maintenance costs. In addition, in other embodiments, the protective tube section 16 and the protective cover 17 may not be provided, and the air nozzle 15 is exposed to the outside after extending out of the bottom plate 12.

[0037] In this embodiment, the lower drainage cavity is a tower-shaped cavity, and the cover body is a tower-shaped cover body. The tower-shaped cavity and the tower-shaped cover body are structurally adapted to make the water flow direction at different heights relatively uniform. In addition, in other embodiments, the lower drainage cavity may also be a columnar cavity or a conical cavity; the cover body may also be a columnar cover body or a box-shaped cover body.

[0038] Another aspect of the present invention provides a fire hydrant drainage system, which includes a ground main structure and an underground fire main pipeline. The ground main structure includes: Figure 2 The fire hose interface 25, water diversion pipe 20, rotating mechanism 19, sheath 21 and telescopic mechanism 18 are shown, and the underground main water supply pipeline 22 is provided with a water inlet valve 23 and a drainage device. Since the embodiment of the drainage device is the same as the embodiment of the drainage device 24 mentioned above, it will not be repeated here.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should also be included in the protection scope of the present invention.

Claims

1. A water discharge device, characterized in that: The utility model comprises a valve body, the upper end of which is used to be connected with the main water supply pipeline, a valve core is movably installed with upper and lower guides in the valve cavity of the valve body, a valve core mating surface which cooperates with the valve core is provided in the valve cavity, an elastic member which provides an upward force to the valve core is arranged between the valve body and the valve core, so that the valve core is in a high conduction position separated from the valve core mating surface in a natural state, the valve core has an upward pressure-bearing surface, a water-blocking and pressure-boosting plate is provided above the valve core in the valve cavity, and a high-pressure water spraying hole facing the pressure-bearing surface is provided on the water-blocking and pressure-boosting plate. When there is high-pressure water in the main water supply pipeline, the high-pressure water impacts the valve core through the high-pressure water spraying hole, and the valve core overcomes the force of the elastic member under the impact and moves downward until it is in a cut-off position which fits with the valve core mating surface, and when the main water supply pipeline loses pressure, the elastic member overcomes the water pressure and drives the valve core to reset.

2. The water discharge device according to claim 1, characterized in that: The valve core comprises a plate-shaped core body, and the pressure-bearing surface is the upper plate surface of the plate-shaped core body.

3. The water discharge device according to claim 2, characterized in that: The valve cavity comprises a funnel-shaped inner cavity, in which the plate-shaped core body is located. When in the cut-off position, the outer edge surface of the plate-shaped core body is sealed and matched with the inner wall surface of the funnel-shaped inner cavity.

4. The water discharge device according to claim 3, characterized in that: The valve cavity has a lower drainage cavity on the lower side of the funnel-shaped inner cavity, the funnel-shaped inner cavity is connected to the lower drainage cavity, the valve core includes a top support bottom on the lower side of the plate-shaped core body, the elastic member is arranged in the lower drainage cavity and directly acts on the top support bottom of the valve core.

5. The water discharge device according to any one of claims 2 to 4, characterized in that: The valve core includes an upwardly extending straightening rod located on the upper part of the plate-shaped core body. A straightening hole for the straightening rod to pass through is provided on the water-blocking and pressurizing plate. The cross-sectional size of the straightening rod is smaller than the cross-sectional size of the straightening hole so as to realize the straightening of the valve core when the guide movement of the valve core deviates.

6. The water discharge device according to claim 4, characterized in that: The elastic part is an elastic air bag, and the bottom of the top support is disc-shaped.

7. The water discharge device according to claim 6, characterized in that: The funnel-shaped inner cavity has a cavity bottom, and the cavity bottom is provided with a leakage port connected to the lower drainage cavity. The valve core guide is movably installed on the cavity bottom. The lower side of the cavity bottom is fixedly connected with an airbag protection mounting cover, and the elastic airbag is installed in the airbag protection mounting cover. The top support bottom of the valve core extends into the airbag protection mounting cover.

8. The water discharge device according to claim 7, characterized in that: The airbag protective mounting cover comprises a cover body and a bottom plate, the air nozzle of the elastic airbag passes downward through the bottom plate and is locked and fixed by a locking nut so that the elastic airbag is fixedly mounted on the bottom plate, and the bottom plate is detachably connected to the cover body.

9. The water discharge device according to claim 8, characterized in that: A protective tube section surrounding the gas nozzle is provided on the lower side of the bottom plate, and a protective cover is threadedly connected to the bottom of the protective tube section.

10. A fire-fighting water crane drainage system, characterized in that: It comprises a main structure on the ground and a main water supply pipeline underground. The main water supply pipeline is provided with a water inlet valve and a water discharge device. The water discharge device is the water discharge device according to any one of claims 1 to 9.

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