Corrosion-resistant multi-layer composite sealed metal hose assembly

Abstract

The utility model discloses a multilayer composite sealed corrosion -resistant metal hose assembly relates to metal hose technical field, including pipe body and connecting interface, the pipe body comprises corrosion -resistant inner layer, reinforcing seal layer and protection outer layer gradually from inside to outside, the connecting interface sets up in pipe body both ends, contains multilayer composite sealing structure, the corrosion -resistant inner layer with reinforcing seal layer between be provided with auxiliary structure, the utility model discloses a PTFE sliding ring (static seal), elastic packing ring (dynamic compensation) and the three -level sealing structure of metal tooth mechanical lock, realize leakage rate 1*10 ‑9 m 3 / s, and the sealing reliability promotes 60% or more, and PTFE inner layer and ceramic coating outer layer form chemical protection double screen, cooperate 316L stainless steel matrix, make the salt mist corrosion time more than 1000 hours, compared with traditional hose and promote 3 times, double -layer reinforcing layer (stainless steel braid + steel belt spiral) combines elastic seal layer, and the compression capacity is 25MPa, and the tensile strength is 15kN, and the high -pressure, high -frequency vibration working condition is adapted.

Description

Technical Field

[0001] This utility model relates to the field of metal hose technology, and more specifically to a corrosion-resistant metal hose assembly with multi-layer composite sealing. Background Technology

[0002] In the field of industrial fluid transportation, metal hoses are widely used due to their excellent flexibility and pressure resistance. However, traditional metal hoses have the following problems in highly corrosive environments: First, the single-layer sealing structure is prone to leakage due to media erosion or pressure fluctuations, especially under high temperature and high pressure conditions where the risk of seal failure is high; second, their corrosion resistance is insufficient, and direct contact between the metal substrate and corrosive media can easily lead to chemical corrosion, shortening their service life; third, the joints mostly use single thread seals or rubber ring seals, lacking a dynamic compensation mechanism, making it difficult to adapt to the attenuation of sealing performance caused by pipeline displacement or vibration.

[0003] While existing technologies offer improvements by adding sealing layers or using corrosion-resistant materials, they generally suffer from complex structures, high manufacturing costs, or insufficient sealing reliability. Therefore, there is an urgent need for a metal flexible hose assembly with a rational structure, excellent sealing performance, and strong corrosion resistance. Utility Model Content

[0004] The purpose of this invention is to provide a multi-layer composite sealed corrosion-resistant metal hose assembly to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A multi-layer composite sealed corrosion-resistant metal hose assembly includes a tube body and a connecting interface. The tube body includes, from the inside out, a corrosion-resistant inner layer, a reinforced sealing layer, and a protective outer layer. The connecting interface is located at both ends of the tube body and includes a multi-layer composite sealing structure. An auxiliary structure is provided between the corrosion-resistant inner layer and the reinforced sealing layer.

[0007] A further improvement of this utility model is that the corrosion-resistant inner layer is made of polytetrafluoroethylene (PTFE) or perfluoroethylene propylene (FEP) with a thickness of 0.3-0.5 mm.

[0008] A further improvement of this utility model is that the reinforcing sealing layer includes a first reinforcing layer, an elastic sealing layer, and a second reinforcing layer arranged sequentially from the inside to the outside; the first reinforcing layer is a stainless steel wire woven mesh with a mesh count of 80-120; the elastic sealing layer is a layer of ethylene propylene diene monomer (EPDM) or fluororubber (FKM) filling the gaps in the first reinforcing layer, with a thickness of 1-2 mm; the second reinforcing layer is a steel strip spiral winding layer with a steel strip thickness of 0.1-0.2 mm and a spiral angle of 30°-45°.

[0009] A further improvement of the present invention is that the protective outer layer is a spirally wound layer of 316L stainless steel strip, and the surface is coated with a ceramic coating with a thickness of 0.05-0.1mm.

[0010] A further improvement of this utility model is that the connection interface includes an interface body and a triple sealing structure; the interface body is a forged 316L stainless steel connector with a trapezoidal thread (tooth angle 30°) machined on the inner wall; the triple sealing structure includes a PTFE slip ring embedded in the inner wall of the interface, an O-ring fluororubber seal in the middle, and stepped metal teeth on the outer side; the O-ring seal is provided with a preload of 50-100N by a spring preload device.

[0011] A further improvement of this utility model is that the auxiliary structure is an annular negative pressure ring disposed between the corrosion-resistant inner layer and the first reinforcing layer. The annular negative pressure ring is made of stainless steel with a thickness of 0.2 mm and is fixed by mechanical nesting.

[0012] Due to the adoption of the above technical solution, the technological progress achieved by this utility model compared to the prior art is as follows:

[0013] 1. This utility model provides a corrosion-resistant metal hose assembly with multi-layer composite sealing. The multi-layer composite sealing system consists of a three-stage sealing structure that mechanically locks together a PTFE slip ring (static seal), an elastic sealing ring (dynamic compensation), and metal teeth, achieving a leakage rate ≤1×10⁻⁶. -9 m 3 / s, improving sealing reliability by more than 60%.

[0014] 2. This utility model provides a multi-layer composite sealed corrosion-resistant metal hose assembly with enhanced corrosion resistance: the PTFE inner layer and the ceramic coating outer layer form a chemical protection double barrier, combined with a 316L stainless steel substrate, making the salt spray corrosion resistance time exceed 1000 hours, which is 3 times higher than that of traditional hoses.

[0015] 3. This utility model provides a multi-layer composite sealed corrosion-resistant metal hose assembly with optimized structural strength: a double-layer reinforcing layer (stainless steel braided mesh + steel strip spiral) combined with an elastic sealing layer, with a pressure resistance ≥25MPa and a tensile strength ≥15kN, adaptable to high-pressure and high-frequency vibration conditions.

[0016] 4. This utility model provides a corrosion-resistant metal hose assembly with multi-layer composite sealing, dynamic adaptability: the spring preload device automatically compensates for the wear of the sealing ring, the annular negative pressure ring solves the problem of negative pressure delamination, the applicable temperature range is -50℃ to 200℃, and the adaptability to medium pressure fluctuations is improved by 40%. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram showing the detailed structure of the interface of this utility model;

[0019] Figure 3 This is a schematic diagram of the tube structure of this utility model;

[0020] Figure 4 This is an enlarged schematic diagram of the structure at point A of this utility model.

[0021] In the diagram: 1. Corrosion-resistant inner layer; 2. First reinforcing layer; 3. Elastic sealing layer; 4. Second reinforcing layer; 5. Protective outer layer; 6. Interface body; 7. PTFE slip ring; 8. O-ring seal; 9. Spring preload device; 10. Metal teeth; 11. Annular negative pressure ring; 12. Pipe body; 13. Connection interface. Detailed Implementation

[0022] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] The present invention will be further described in detail below with reference to embodiments:

[0024] Example 1

[0025] like Figure 1-4 As shown, this utility model provides a multi-layer composite seal corrosion-resistant metal hose assembly, including a tube body 12 and a connection interface 13. The tube body 12 includes a corrosion-resistant inner layer 1, a reinforced sealing layer and a protective outer layer 5 from the inside to the outside. The connection interface 13 is disposed at both ends of the tube body 12 and includes a multi-layer composite seal structure. An auxiliary structure is provided between the corrosion-resistant inner layer 1 and the reinforced sealing layer.

[0026] The corrosion-resistant inner layer 1 is made of polytetrafluoroethylene (PTFE) or perfluoroethylene propylene (FEP) with a thickness of 0.3-0.5 mm.

[0027] The reinforcing sealing layer includes a first reinforcing layer 2, an elastic sealing layer 3, and a second reinforcing layer 4 arranged sequentially from the inside out; the first reinforcing layer 2 is a stainless steel wire woven mesh with a mesh size of 80-120; the elastic sealing layer 3 is a layer of ethylene propylene diene monomer (EPDM) or fluororubber (FKM) filling the gaps in the first reinforcing layer 2, with a thickness of 1-2 mm; the second reinforcing layer 4 is a steel strip spiral winding layer with a steel strip thickness of 0.1-0.2 mm and a spiral angle of 30°-45°.

[0028] The outer protective layer 5 is a spiral-wound layer of 316L stainless steel strip, with a ceramic coating of 0.05-0.1mm thickness sprayed on the surface.

[0029] Example 2

[0030] like Figure 1-4 As shown, based on Embodiment 1, the present invention provides the following technical solution: Preferably, the connection interface 13 includes an interface body 6 and a triple sealing structure; the interface body 6 is a forged 316L stainless steel connector with a trapezoidal thread (tooth angle 30°) machined on the inner wall; the triple sealing structure includes a PTFE slip ring 7 embedded in the inner wall of the interface, an O-ring seal 8 in the middle, and a stepped metal tooth 10 on the outer side; the O-ring seal 8 is provided with a preload force of 50-100N by a spring preload device 9.

[0031] The auxiliary structure is an annular negative pressure ring 11 set between the corrosion-resistant inner layer 1 and the first reinforcing layer 2. The annular negative pressure ring 11 is made of stainless steel with a thickness of 0.2mm and is fixed by mechanical nesting.

[0032] Example 3

[0033] like Figure 1-4 As shown, based on Embodiment 1, the present invention provides the following technical solution: Preferably, the corrosion-resistant inner layer 1 is made of a molded PTFE tube with an inner wall roughness Ra≤0.2μm and a thickness of 0.4mm, and is bonded to the stainless steel wire mesh of the first reinforcing layer 2 by a hot-melt process, with a bonding strength ≥5MPa.

[0034] Reinforced sealing layer: First reinforcement layer 2: 304 stainless steel wire, 100 mesh, warp and weft weaving angle 90°, forming a uniform mesh structure;

[0035] Elastic sealing layer 3: Liquid fluororubber is injected into the gaps of the woven mesh, and after vulcanization, the thickness is 1.5mm and the Shore hardness is 65A; Second reinforcing layer 4: 0.15mm thick 316L stainless steel strip is wound at a 40° helical angle with a pitch of 5mm, and is tightly attached to the first reinforcing layer.

[0036] The outer protective layer 5 is made of 0.2mm thick 316L stainless steel strip spirally wound (8mm pitch), with an Al2O3 ceramic coating sprayed on the surface. The coating thickness is 0.08mm, and a dense protective layer is formed by high-temperature sintering.

[0037] The interface body 6 of the connection interface 13 is made of forged 316L stainless steel, with trapezoidal threads (pitch 2mm, tooth angle 30°) machined on the inner wall and thread depth 1.5mm, forming a mechanical engagement with the steel strip spiral of the second reinforcing layer 4 of the tube body 12.

[0038] Triple sealing structure: First sealing layer: PTFE slip ring 7 is interference-fitted into the groove of the inner wall of the interface, with a slip ring thickness of 2mm, forming a 0.5mm axial sealing surface with the end face of the corrosion-resistant inner layer 1;

[0039] Second sealing layer: O-ring (3mm diameter) is installed in the annular groove in the middle of the interface, and spring preload device 9 (spring stiffness 10N / mm, pre-compression 5mm) provides 80N preload force;

[0040] The third sealing layer 10: Three sets of stepped metal teeth (tooth height 0.5mm, tooth pitch 1mm) are machined on the outside of the interface to form a 3mm deep embedded locking with the groove of the matching flange.

[0041] Negative pressure protection: Annular negative pressure rings 11 (5mm wide, 0.2mm thick) are spot-welded to the outer surface of the corrosion-resistant inner layer 1, evenly distributed at 50mm intervals to prevent the inner layer from collapsing under negative pressure. Assembly and testing: After threaded engagement of both ends of the tube body 12 with the interface body 6, PTFE slip rings, O-ring seals 8, and spring preload devices 9 are installed in sequence. PTFE tape is wrapped around the threads, and a silicone sealing sleeve is fitted onto the outside and heat-shrinkable for fixation.

[0042] The finished product must pass the following tests:

[0043] Static pressure test: No leakage was observed after holding the pressure at 25MPa for 30 minutes.

[0044] Pulse test: 100,000 cycles of 10-25MPa pressure, no decrease in sealing performance;

[0045] Salt spray test: Sprayed with 5% NaCl solution for 1000 hours, no rust was found on the surface and no penetration was observed in the inner layer.

[0046] The working principle of this multi-layer composite sealed corrosion-resistant metal hose assembly will be explained in detail below.

[0047] like Figure 1-4 As shown, the multi-layer composite sealed corrosion-resistant metal hose assembly provided by this utility model achieves sealed protection against corrosive media and stable operation under complex working conditions through the synergistic effect of the multi-layer composite structure of the hose body 12 and the triple sealing structure of the connection interface 13. The specific working principle is as follows:

[0048] I. Synergistic Sealing and Protection Principle of the 12-Layer Composite Structure of the Pipe Body

[0049] The media isolation function of corrosion-resistant inner layer 1

[0050] Made of polytetrafluoroethylene (PTFE) or perfluoroethylene propylene (FEP), utilizing its excellent chemical inertness and corrosion resistance, it directly contacts the transported medium, blocking chemical erosion between the medium and the outer structure. The molded PTFE tube has a low inner wall roughness (Ra≤0.2μm) and a thickness of 0.4mm. It is bonded to the stainless steel wire mesh of the first reinforcing layer 2 through a hot-melt process (bonding strength ≥5MPa), ensuring a tight bond between the inner layer and the reinforcing layer and preventing the medium from penetrating into the interlayer gaps.

[0051] Enhanced mechanical support and dynamic sealing of the sealing layer

[0052] First reinforcing layer 2: 80-120 mesh stainless steel wire woven mesh (such as 100 mesh 304 stainless steel wire in Example 3, woven at 90° in the warp and weft directions) forms a uniform mesh structure, providing mechanical support for the inner layer and resisting radial expansion caused by the internal pressure of the medium and external mechanical stress.

[0053] Elastic sealing layer 3: Liquid EPDM or fluororubber (FKM) is injected into the gaps of the braided mesh and then vulcanized (thickness 1-2mm). It fills the mesh holes and forms a continuous elastomer. Under pressure, it deforms to fill the micro gaps and achieves dynamic sealing. Its elastic properties with a Shore hardness of 65A make it both flexible and tear-resistant, and it can adapt to the deformation when the hose is bent.

[0054] The second reinforcing layer 4 consists of a 0.1-0.2mm thick steel strip (such as 316L stainless steel strip) wound at a 30°-45° helical angle (5mm pitch), which is tightly fitted with the first reinforcing layer 2 to form a "rigid-flexible" composite support structure: the helical steel strip restricts excessive radial expansion while allowing axial stretching and compression within a certain range, thus improving the fatigue resistance of the hose.

[0055] External protection of outer layer 5

[0056] The 316L stainless steel strip is spirally wound (0.2mm thickness, 8mm pitch) to form a mechanical protective layer, resisting external impact, wear and stress; the surface is sprayed with a 0.05-0.1mm ceramic coating (such as Al2O3), which is sintered at high temperature to form a dense oxide film, further isolating it from corrosive environments such as humidity and salt spray (e.g., no rust after 1000 hours of salt spray testing), extending the service life of the hose.

[0057] II. Multi-stage sealing mechanism of triple sealing structure of connection interface 13

[0058] First sealing layer: PTFE slip ring 7 axial seal

[0059] The PTFE slip ring 7 is interference-fitted into the groove on the inner wall of the interface, forming a 0.5mm axial sealing surface with the end face of the corrosion-resistant inner layer 1. Utilizing the low friction and chemical stability of PTFE, under the action of medium pressure, the slip ring 7 presses the end face of the inner layer axially, blocking the leakage of medium along the gap between the inner wall of the interface and the pipe body 12, while accommodating slight axial displacement.

[0060] Second sealing layer: O-ring 8 radial dynamic seal

[0061] An O-ring seal 8 (3mm diameter) is installed in the annular groove in the middle of the interface. A preload of 50-100N is provided by a spring preload device 9 (e.g., in Example 3, the spring stiffness is 10N / mm, the pre-compression is 5mm, and the preload is 80N). Under the pressure of the medium or external vibration, the seal 8 is radially compressed and deformed, tightly fitting the mating surfaces of the interface and the connecting parts, compensating for machining tolerances and dynamic deformation, and ensuring long-term sealing reliability (no attenuation after 100,000 pulse tests).

[0062] Third sealing layer: stepped metal teeth 10 mechanical locking

[0063] The three sets of stepped metal teeth 10 (tooth height 0.5mm, tooth pitch 1mm) on the outside of the interface form a 3mm deep embedded locking with the matching flange groove. The mechanical interlocking restricts the relative displacement between the interface and the flange, preventing the sealing ring 8 from failing due to excessive stretching or torsion. At the same time, it forms a physical barrier to block the leakage of the medium along the outside of the interface, which is especially suitable for high pressure and high frequency vibration conditions.

[0064] III. Negative Pressure Protection and Assembly Reinforcement of Auxiliary Structures

[0065] Anti-collapse design of annular negative pressure ring 11

[0066] Stainless steel annular negative pressure rings 11 (5mm wide, 0.2mm thick, spaced 50mm apart) are fixed to the outer surface of the corrosion-resistant inner layer 1 by mechanical nesting or spot welding, forming an annular support structure. When negative pressure occurs inside the pipe, the negative pressure rings 11 resist the radial contraction of the inner layer, preventing the inner layer from collapsing or wrinkling due to the pressure difference between the inside and outside, and ensuring the structural integrity of the hose under alternating positive and negative pressure environments.

[0067] Sealing enhancement in assembly process

[0068] The pipe body 12 and the interface body 6 are mechanically engaged by a trapezoidal thread (30° thread angle, 2mm pitch). The thread depth is 1.5mm and it forms a spiral engagement with the steel strip of the second reinforcing layer 4 to enhance the connection strength. Polytetrafluoroethylene raw material tape is wrapped around the thread, and a silicone sealing sleeve is inserted on the outside and heat-shrinked to fix it, further sealing the thread gap and forming multiple sealing redundancies.

[0069] IV. Operating Condition Adaptability and Performance Assurance

[0070] Through the above structural design, the hose assembly achieves the following:

[0071] High-pressure sealing: No leakage was observed after holding the static pressure at 25MPa for 30 minutes. This is achieved through the combined pressure bearing of the steel strip spiral of the reinforced sealing layer and the elastic rubber, as well as the gradient pressure compensation of the triple seal at the interface.

[0072] Dynamic fatigue resistance: The sealing performance showed no degradation after 100,000 cycles of pulse testing at 10-25MPa, thanks to the flexible support of the braided mesh and spiral steel belt, which reduced stress concentration;

[0073] Corrosion resistance and environmental adaptability: The protective outer layer 5 ceramic coating is combined with the corrosion-resistant inner layer 1, and is made of 316L stainless steel to meet the long-term use requirements in harsh environments such as salt spray and acid and alkali.

[0074] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A multi-layer composite sealed corrosion-resistant metal hose assembly, comprising a hose body (12) and a connecting interface (13), characterized in that: The tube body (12) includes a corrosion-resistant inner layer (1), an enhanced sealing layer and a protective outer layer (5) from the inside to the outside. The connection interface (13) is located at both ends of the tube body (12) and includes a multi-layer composite sealing structure. An auxiliary structure is provided between the corrosion-resistant inner layer (1) and the enhanced sealing layer.

2. The corrosion-resistant metal hose assembly with multi-layer composite sealing according to claim 1, characterized in that: The corrosion-resistant inner layer (1) is made of polytetrafluoroethylene or polytetrafluoroethylene, with a thickness of 0.3-0.5 mm.

3. The corrosion-resistant metal hose assembly with multi-layer composite sealing according to claim 1, characterized in that: The reinforced sealing layer includes a first reinforcing layer (2), an elastic sealing layer (3), and a second reinforcing layer (4) arranged sequentially from the inside to the outside; the first reinforcing layer (2) is a stainless steel wire woven mesh with a mesh count of 80-120; the elastic sealing layer (3) is a layer of EPDM rubber or fluororubber filling the gaps in the first reinforcing layer (2), with a thickness of 1-2 mm; the second reinforcing layer (4) is a steel strip spiral winding layer with a steel strip thickness of 0.1-0.2 mm and a spiral angle of 30°-45°.

4. The corrosion-resistant metal hose assembly with multi-layer composite sealing according to claim 1, characterized in that: The protective outer layer (5) is a spiral-wound layer of 316L stainless steel strip, with a ceramic coating of 0.05-0.1mm thickness sprayed on the surface.

5. The corrosion-resistant metal hose assembly with multi-layer composite sealing according to claim 1, characterized in that: The connection interface (13) includes an interface body (6) and a triple sealing structure; the interface body (6) is a forged 316L stainless steel connector with trapezoidal threads machined on the inner wall; the triple sealing structure includes a PTFE slip ring (7) embedded in the inner wall of the interface, an O-ring seal (8) in the middle and stepped metal teeth (10) on the outer side; the O-ring seal (8) is provided with a preload of 50-100N by a spring preload device (9).

6. The corrosion-resistant metal hose assembly with multi-layer composite sealing according to claim 1, characterized in that: The auxiliary structure is an annular negative pressure ring (11) set between the corrosion-resistant inner layer (1) and the first reinforcing layer (2). The annular negative pressure ring (11) is made of stainless steel with a thickness of 0.2 mm and is fixed by mechanical nesting.

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