Metal hose for high-pressure water-based fog fire extinguishing system

Abstract

The utility model relates to a metal hose for a high-pressure water-based fog fire extinguishing system, and belongs to the technical field of fire extinguishing pipelines. The hose comprises a first connector assembly and a second connector assembly which are fixedly connected to the two ends of a flexible body. A main body of the first joint assembly is formed by butt welding a conical connecting pipe with an outer section being an expanding gradually-shrinking outer conical section and one of the inner connecting pipes, and a loop nut is sleeved outside a straight pipe of the conical connecting pipe; the second joint assembly is formed by butt welding of an external thread joint and another internal connecting pipe; the flexible body consists of an inner-layer metal corrugated hose of which the outer layer is covered with a metal wire mesh sleeve; the two ends of the corrugated hose are cut off at wave crests respectively, 1.5-3.5 corrugated knocking and gathering ends are formed, the knocking and gathering ends are fixedly connected with the inner end of the inner connecting pipe in a welded mode, and the welding position of the corrugated hose and the inner connecting pipe is sleeved with a net cover fixed through a buckling ring in a buckled mode. According to the utility model, the overall bursting strength is obviously improved; and the service life of the metal hose for the high-pressure water-based fog fire extinguishing system is remarkably prolonged.

Description

Technical Field

[0001] The utility model relates to a metal hose, in particular to a metal hose for a high-pressure water-based mist fire extinguishing system, belonging to the technical field of fire-fighting pipelines. Background Art

[0002] In order to overcome the shortcomings of traditional fire-fighting systems that use relatively low pressure sources to drive water sprinklers for fire extinguishing, resulting in large water consumption and unsatisfactory fire-fighting effects, the high-pressure water-based mist fire-fighting system uses fine water-based mist formed by high-pressure water flowing through special nozzles to extinguish fires. The average diameter of the fine water-based mist droplets sprayed out is 50μm to 200μm. When encountering the high temperature of the flame, it quickly vaporizes, greatly reducing the oxygen concentration. It has strong vaporization cooling, oxygen isolation and suffocation, dilution of combustible gases and heat insulation effects, and can achieve rapid fire extinguishing.

[0003] The formation of fine water-based mist requires a pressure source of 10MPa to 25MPa. For example, a DN08 metal hose used in a yacht water-based mist fire extinguishing system has a design pressure of 18MPa, a burst pressure of more than 72MPa when the bending radius is 50mm, and a service life of 25 years. However, the burst pressure of metal hoses used in traditional firefighting systems is only about 50MPa, which cannot meet the strength requirements, and will corrode and perforate after several years of use, resulting in a short service life. Utility Model Content

[0004] The purpose of the utility model is to improve the structure of the above-mentioned existing technology to provide a metal hose for a high-pressure water-based mist fire extinguishing system whose bursting pressure can meet the use requirements, thereby adapting to the development of fire fighting technology.

[0005] In order to achieve the above-mentioned purpose, the basic technical scheme of the metal hose for high-pressure water-based mist fire extinguishing system of the utility model is: it is composed of a first joint assembly and a second joint assembly fixedly connected to both ends of the flexible body;

[0006] The main body of the first joint assembly is formed by butt welding a tapered pipe having an outer section of an expanded and tapered outer cone section and one of the inner pipes, and a slip-on nut is provided on the outer sleeve of the straight pipe of the tapered pipe; the second joint assembly is formed by butt welding an external threaded joint and another inner pipe;

[0007] The flexible body is composed of an inner metal corrugated hose with an outer metal mesh sleeve;

[0008] The two ends of the metal corrugated hose are cut off at the wave crests respectively, and 1.5 to 3.5 corrugated flattened and gathered ends are formed, and the flattened and gathered ends are welded and fixedly connected to the inner end of the inner pipe. The outer jacket of the metal corrugated hose and the inner pipe is buckled and fixed to the mesh sleeve by a buckling ring at the welding point.

[0009] A further improvement of the utility model is that the inner section of the inner pipe is an enlarged diameter section.

[0010] A further improvement of the utility model is that the outer circle of the outer section of the external threaded joint has an external thread matched with the slip-on nut, and the inner hole is a tapered hole matched with the tapered outer cone section of the tapered connecting pipe.

[0011] A further improvement of the utility model is that the metal corrugated hose is a dense-wave annular metal corrugated hose with a ratio of wave pitch to median diameter of ≤20%.

[0012] A further improvement of the utility model is that an O-ring is embedded in the outer cone section of the conical pipe.

[0013] Compared with existing fire-fighting metal hoses, the utility model has significantly improved overall burst strength; the end treatment method of cutting the wave crest and then flattening it is adopted, so that the corrugated pipe can withstand the corrosive environment caused by the static pressure of fire-fighting water for a long time, and significantly improves the service life of the metal hose used in the high-pressure water-based mist fire-extinguishing system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an embodiment of the utility model.

[0015] Figure 2 yes Figure 1 A schematic diagram of a partially enlarged structure of an embodiment. Implementation Example

[0016] A metal hose for a high-pressure water-based mist fire extinguishing system is used in a yacht fire-fighting fine water-based mist sprinkler system with a caliber of DN08 and a total length of 600mm. The actual use pressure is 14MPa and the required design pressure is 18MPa. The hose is bent into several circles with a radius of 50mm in the flexible body for bursting pressure testing, and the bursting pressure meets ≥72Pa.

[0017] To this end, the applicant conducted relevant research and realized that: as an important connector of the sprinkler system pipeline, it continuously bears high pressure from fire water during its life cycle. In the non-working state, the fire water is in a static state for a long time. Pressure fluctuations will only occur when the pipeline expands and contracts due to temperature changes. The pressure is stabilized by the pressure relief valve and the booster pump. For example, when the pressure drop reaches the system setting value, the system will automatically start the water pump to increase the pressure. In addition to the high water pressure, the technical problems that the hose needs to face are the corrosiveness of fire water, because fire water contains 5-10 mg / L of chloride ions. If the cut section of the bellows is continuously immersed in water, the end face has no oxide film, the texture is rough and contains a large amount of impurities such as chromium carbide, which is easily corroded by chloride ions. Once corrosion occurs, it is easy to expand and extend when the fire water flows until the bellows is corroded and perforated and fails; in addition, corrosion products such as iron oxide are transmitted in the fire pipeline. In addition to local scaling, it can also wear the seals in the water pump and other components, and even cause leakage.

[0018] Based on the above research, the metal hose for high-pressure water-based mist fire extinguishing system provided in this embodiment is as follows Figure 1 and Figure 2 As shown, it is composed of a flexible body 1, a first joint component 2 and a second joint component 3 located at two ends of the flexible body 1.

[0019] The main body of the first joint assembly 2 is formed by butt welding a tapered pipe 8 whose outer section is a 24° expanded and tapered outer cone section and an internal pipe 7 whose inner section is an expanded diameter section, the outer cone section of the tapered pipe 8 is embedded with an O-ring 10, and the outer sleeve of the straight pipe is covered with a slip-on nut 9. The second joint assembly 3 is formed by butt welding an external threaded joint 11 and an internal pipe 7 whose inner section is an expanded diameter section, the outer circle of the outer section of the external threaded joint 11 has an external thread adapted to the slip-on nut 9, and the inner hole is a tapered hole adapted to the tapered outer cone section of the tapered pipe 8, so that the two joint assemblies 2 and 3 can be connected end to end.

[0020] The flexible body 1 is composed of an inner stainless steel corrugated hose 6 covering an outer stainless steel wire mesh sleeve 5. In actual manufacturing, the two ends of the corrugated hose 6 are cut off at the wave crests when cutting, and then the positive wave side of 1.5 (1.5 to 3.5) waves away from the end is flattened to form a gathered end, and all the wave crests of the flattened gathered end are welded to the inner end of the inner pipe 7, and then put on the mesh sleeve 5, and the mesh sleeve 5 at the welding point of the corrugated hose 6 and the inner pipe 7 is fixed after being buckled with the buckling ring 4. Then, the outer ends of the inner pipe 7 at both ends are respectively butt-welded to the tapered pipe 8 and the external threaded joint 11. Except that the O-ring 10 is made of rubber NBR and the slip-on nut is made of carbon steel galvanized, the rest are made of stainless steel.

[0021] When in use, this embodiment is installed in the pipeline from the outlet of the pump group to the nozzle, the external threaded joint 11 is tightened and connected with the nut pipe (with O-ring) assembly at the nozzle end, and the tapered pipe 8 and the O-ring 10 are connected with the external threaded joint at the outlet of the pump group through the slip-on nut 9, so as to achieve sealing, withstand high pressure, compensate for installation deviation, and reduce shock.

[0022] Practice has proved that the average bursting pressure of this embodiment is increased from 58MPa to 77Mpa, which can fully meet the bursting strength requirement of 72MPa. In addition, the design of cutting the material from the wave crest and then flattening it can achieve a smooth inner wall without any burrs, avoiding the corrosion problem of the traditional cutting method of cutting the material from the wave trough and then immersing the cutting port in the fire-fighting water containing chloride ions. As an important pipeline connector used in the yacht cabin, the metal hose for the high-pressure water-based mist fire extinguishing system has passed all Lloyd's certification type tests and also passed the 1440-hour acid salt spray test.

[0023] In summary, this embodiment has the following beneficial effects:

[0024] The bellows adopts dense waves, and the metal mesh sleeve adopts more reasonable weaving parameters, which can significantly reduce the circumferential film stress borne by the bellows, thereby improving the bursting strength of the corrugated flexible body, and at the same time make the hose suitable for installation occasions with smaller bending radius;

[0025] The wave crest at the end of the bellows is cut off and then flattened, and the cut surface is welded to the inner pipe to avoid direct contact between the cut surface and the fire water, thus avoiding corrosion. The inner wall of the hose is clean and beautiful, without burrs, welding slag, and corrosive substances, ensuring the safe and normal operation of other components of the sprinkler system;

[0026] 3) The double sealing structure of the slip-on nut, 24° conical joint and O-ring is adopted. Even if the O-ring ages and causes the seal to fail, the mechanical sealing method of the cone-cone combination can still ensure the sealing performance of the joint assembly. It can also absorb the vibration of pressure sources such as water pumps and adapt to the occasions where the fire protection system is installed in a sports environment.

[0027] The present invention is not limited to the above-mentioned embodiments. Any technical solution formed by equivalent replacement or transformation, whether used in a fire protection system or other application scenarios, falls within the protection scope required by the present invention.

Claims

1. A metal hose for a high-pressure water-based mist fire extinguishing system, comprising a first joint assembly and a second joint assembly fixedly connected to both ends of a flexible body; The main body of the first joint assembly is formed by butt welding a tapered pipe having an outer section of an expanded and tapered outer cone section and one of the inner pipes, and a slip-on nut is provided on the straight pipe outer sleeve of the tapered pipe; the second joint assembly is formed by butt welding an external threaded joint and another inner pipe; the flexible body is formed by an inner metal corrugated hose with an outer layer covered with a metal wire mesh sleeve; Features: The two ends of the metal corrugated hose are cut off at the wave crests, and 1.5 to 3.5 corrugated flattened and gathered ends are formed, and the flattened and gathered ends are welded and fixed to the inner end of the inner pipe. The outer jacket buckling ring buckles and fixes the mesh sleeve at the welding point between the metal corrugated hose and the inner pipe.

2. The metal hose for high-pressure water-based mist fire extinguishing system according to claim 1 is characterized in that: The inner section of the inner tube is an expanded diameter section.

3. The metal hose for high-pressure water-based mist fire extinguishing system according to claim 2 is characterized in that: The outer circle of the outer section of the external thread joint has an external thread matched with the slip-on nut, and the inner hole is a tapered hole matched with the tapered outer cone section of the tapered connecting pipe.

4. The metal hose for high-pressure water-based mist fire extinguishing system according to claim 3 is characterized in that: The metal corrugated hose is a dense-wave annular metal corrugated hose with a ratio of wave pitch to median diameter of ≤20%.

5. The metal hose for high-pressure water-based mist fire extinguishing system according to claim 4, characterized in that: The outer cone section of the conical pipe is embedded with an O-ring.

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