Zirconium material port reducing integral flange and liner tube structure thereof

Abstract

The invention discloses a zirconium material opening reducing integral flange and a liner tube structure thereof, and belongs to the technical field of special material flange connection, the zirconium material opening reducing integral flange comprises a liner tube, a first flange and a second flange, and the double flanges sleeve the surface of the liner tube and are fixed through locking bolts; a first zirconium sealing face is arranged between the first flange and the liner tube, a sealing assembly is arranged between the connecting faces of the two flanges, the assembly comprises a second zirconium sealing face embedded in a sealing groove and is pressed and fixed through a zirconium screw, and the screw and the sealing face form a wedge-shaped plug welding area which is sealed through argon tungsten-arc welding. And a spiral-wound gasket filled with a zirconium belt and fluoride is arranged in the sealing surface. Through a double-side flange integrated structure and a double zirconium sealing surface and integrated plug welding structure, the sealing performance and the corrosion resistance are improved, electrochemical corrosion is avoided, and the sealing device is suitable for extreme working conditions of chemical engineering, petrochemical engineering and the like and has the advantages of being compact in structure, convenient to install, long in service life and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of special material flange connection, and particularly relates to a zirconium material nozzle reducer integral flange and a liner pipe structure thereof. BACKGROUND

[0002] In the high-end manufacturing field of chemical industry, petrochemical industry, medicine and the like, the nozzle flange as a core component for connecting equipment and pipelines directly relates to the safe operation of the system in terms of sealing performance, corrosion resistance and structural stability. Zirconium material is widely used in equipment under severe corrosion conditions, such as reactors, heat exchangers, storage tanks and pipelines, because it has excellent corrosion resistance and can resist the corrosion of most strong chemical media such as acids, alkalis and salts. However, the existing zirconium nozzle flange structure still has the following technical defects in actual application: If the traditional flange wants to realize the variable diameter connection, the combined structure of "equipment pipe flange + flange cover" is usually adopted, which needs to be welded and fixed after the hole is opened on the flange cover and the pipeline is inserted. Since zirconium material cannot be directly welded with other steel types, in order to ensure the sealing effect, zirconium plates need to be connected on both sides of the flange cover, which greatly increases the wall thickness of the liner pipe (usually 2-3 times of the conventional design), not only increasing the manufacturing cost, but also increasing the processing difficulty. At the same time, the connection between the flange on the other end and the zirconium pipe is mostly in the form of a live sleeve, which is poor in stress condition. If a necked butt welding structure is used, the entire flange needs to be made of zirconium material, further increasing the engineering cost.

[0003] In terms of sealing performance, the traditional flange mostly relies on a single sealing surface design, which realizes sealing by directly pressing the gasket with bolts. In high temperature (>200℃), high pressure (>10MPa) or strong corrosive medium environment, the sealing may fail due to small deformation of the flange surface, aging of the gasket or decay of the bolt pre-tightening force, and there is a risk of leakage. The existing sealing gasket (such as rubber gasket, asbestos gasket) may lose its resilience or the material may decompose under extreme conditions, and the metal gasket may be prone to crevice corrosion due to the mismatch of the expansion coefficient with zirconium material.

[0004] In addition, the connection between the traditional flange and the liner pipe is usually by welding or sleeving: the welding process may produce a heat-affected zone, resulting in a decrease in the corrosion resistance of zirconium material; the sleeving method may have the risk of crevice corrosion between the liner pipe and the flange. If the fastener and the sealing surface material are made of stainless steel or alloy, electrochemical corrosion may be caused due to the potential difference with zirconium material, shortening the service life of the equipment.

[0005] In view of the above problems, although some technologies attempt to use corrosion-resistant materials such as titanium or hastelloy to replace, there are problems such as high material cost, great processing difficulty, and insufficient compatibility with zirconium liner pipe material, and the traditional split type sealing design cannot meet the long-term stable operation requirement. Therefore, developing a zirconium nozzle flange structure with high sealing performance, corrosion resistance and structural reliability has become the key to solving the problem of equipment connection under extreme conditions. SUMMARY

[0006] The application provides a zirconium material nozzle reducing integral flange and a liner pipe structure thereof, which realizes reliable connection of intermetallic non-welding fusion by setting a sealing assembly, using a split design of a double-sided zirconium sealing surface and an integral flange body, and combining zirconium screw plug welding fixation, so as to solve the problems of insufficient structural strength and sealing failure caused by the welding limitation of zirconium material and realize stable connection under high pressure and strong corrosion working conditions.

[0007] To achieve the above object, the application provides a zirconium material nozzle reducing integral flange and a liner pipe structure thereof, which comprises a liner pipe, a first flange and a second flange, the first flange and the second flange are sleeved on the surface of the liner pipe, and the first flange and the second flange are fixed by shrink bolts, a first zirconium sealing surface is arranged between the end of the first flange away from the second flange and the liner pipe, and a sealing assembly is arranged between the connecting surface of the second flange and the first flange.

[0008] In an embodiment, the sealing assembly comprises a sealing groove opened on the opposite surface of the first flange and the second flange, a second zirconium sealing surface is embedded in the sealing groove, a screw hole is opened through the second zirconium sealing surface and connected to the first flange, a screw is screwed in the screw hole, and the second zirconium sealing surface is pressed and fixed in the sealing groove.

[0009] In an embodiment, the screw and the surface of the second zirconium sealing surface form a wedge-shaped plug welding area after the screw is tightened, the wedge-shaped plug welding area is sealed by plug welding, and the screw and the second zirconium sealing surface form an integrated fixed structure.

[0010] In an embodiment, the screw is made of zirconium, and the size of the screw is selected according to the connection and sealing requirements of the first flange and the second flange.

[0011] In an embodiment, the opening length of the screw hole is 1.5 to 2 times the nominal diameter of the screw.

[0012] In an embodiment, the bevel of the plug welding area within a range of 50 mm needs to be mechanically cleaned before plug welding to remove the surface oxide film and perform degreasing treatment.

[0013] In an embodiment, the plug welding adopts tungsten argon arc welding, and no post-welding heat treatment is performed after plug welding.

[0014] In an embodiment, the first zirconium sealing surface and the second zirconium sealing surface are both provided with a sealing gasket.

[0015] In an embodiment, the sealing gasket adopts a winding gasket.

[0016] Compared with the prior art, the application has the beneficial effects that: By adopting the structure design of double-flange sleeve setting liner pipe, and cooperating with the double sealing mechanism of the first zirconium sealing surface and the sealing assembly, the overall sealing performance and structural stability of the material port connection are significantly improved. The second zirconium sealing surface in the sealing assembly is fixed in the sealing groove through a zirconium screw, and an integrated fixed structure is formed through the wedge-shaped plug welding area plug welding process, effectively preventing the loosening risk that may occur in the traditional connection mode, enhancing the connection strength between the sealing surface and the flange, and avoiding the corrosion risk of exposed fasteners, especially suitable for high-temperature, high-pressure and strong corrosive medium environment.

[0017] The overall application of zirconium materials (including sealing surface, screw) ensures the consistency of the material quality of each component, can effectively prevent electrochemical corrosion, and cooperates with the optimized design of the screw hole length (1.5 to 2 times the nominal diameter of the screw), further guarantees the reliability and anti-tripping capability of the connection.

[0018] Mechanical cleaning and degreasing treatment before plug welding, combined with the tungsten electrode argon arc welding process and the characteristics of post-welding heat treatment-free, not only ensures the welding quality and weld tightness, but also avoids the influence of heat treatment on the corrosion resistance of zirconium materials, prolonging the service life of the assembly.

[0019] In addition, the winding gasket arranged in the sealing surface has excellent resilience and corrosion resistance, can compensate for the slight deformation of the flange surface, ensure the long-term sealing reliability under harsh working conditions, and has compact overall structure and convenient installation, and is suitable for high-end equipment fields such as chemical industry and petrochemical industry which have strict sealing requirements. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0021] Fig. 1 A zirconium material port reducing integral flange and its liner pipe structure are provided. Fig. 2 A zirconium material port reducing integral flange and its liner pipe structure are provided.

[0022] Explanation of reference signs: 1, first flange; 2, first zirconium sealing surface; 3, second zirconium sealing surface; 4, screw; 5, liner pipe; 6, wedge-shaped plug welding area; 7, second flange; 8, locking bolt. DETAILED DESCRIPTION

[0023] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application are clearly and completely described below. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0024] Referring to Figs. 1-2 As shown in the drawings, the present application provides a zirconium material port reducing whole flange and its liner pipe structure, which comprises a liner pipe 5, a first flange 1 and a second flange 7, the first flange 1 and the second flange 7 are sleeved on the surface of the liner pipe 5, and the first flange 1 and the second flange 7 are connected and fixed through a shrink bolt 8, a first zirconium sealing surface 2 is arranged between the end of the first flange 1 away from the second flange 7 and the liner pipe 5, and a sealing assembly is arranged between the connecting surface of the second flange 7 and the first flange 1.

[0025] When connected and installed, the first flange 1 is welded with the equipment body by welding, the liner pipe 5 is inserted into the equipment to a specified position, the second flange 7 is sleeved on the liner pipe 5 and forms a floating connection with the liner pipe 5, then a sealing fit is realized through the first zirconium sealing surface 2 between the end of the first flange 1 away from the second flange 7 and the liner pipe 5, at the same time, a sealing assembly is installed between the connecting surface of the second flange 7 and the first flange 1, after the sealing assembly is installed, the first flange 1 and the second flange 7 are pressed tightly by the locking bolt 8 to ensure reliable connection and tight sealing.

[0026] It should be noted that the first flange 1 and the second flange 7 are concentric double-sided whole flange bodies, the two sides thereof can be processed into flange plates of different sizes by installing the nominal diameter of the connected pipe port, so that the reducing structure design is realized, and the butt joint demand of different pipe diameters is met. At the same time, when the nominal diameter changes, the number of plug weld points on the sealing surface is also adjusted accordingly to ensure the sealing strength and connection stability. The distribution of plug weld points follows the principle of equidistant distribution, and is arranged symmetrically along the circumferential direction of the sealing surface, so that the stress is uniform and local stress concentration is prevented. In the reducing process, the number of plug weld points on the smaller diameter side is appropriately reduced, and the number of plug weld points on the larger diameter side is increased accordingly, so as to adapt to the sealing demand and structural bearing capacity under different diameters.

[0027] Optionally, the sealing assembly comprises a sealing groove opened on the opposite surface of the first flange 1 and the second flange 7, a second zirconium sealing surface 3 is embedded in the sealing groove, a screw hole is opened through the second zirconium sealing surface 3 and communicates to the first flange 1, a screw 4 is screwed into the screw hole, and the second zirconium sealing surface 3 is pressed and fixed in the sealing groove.

[0028] In this embodiment, the second zirconium sealing surface 3 is firmly fixed in the sealing groove by the screw 4, effectively preventing displacement during installation or operation and ensuring sealing stability; at the same time, the close fit of the second zirconium sealing surface 3 and the sealing groove further improves the pressure resistance and leakage resistance of the flange connection.

[0029] Optionally, the screw 4 forms a wedge plug welding area 6 with the surface of the second zirconium sealing surface 3 after being tightened, and the wedge plug welding area 6 is sealed by plug welding, so that the screw 4 and the second zirconium sealing surface 3 form an integrated fixed structure.

[0030] In this embodiment, the setting of the wedge plug welding area 6 not only enhances the connection strength between the screw 4 and the second zirconium sealing surface 3, but also effectively eliminates the risk of loosening caused by vibration or thermal cycling, further improving the long-term reliability of the sealing structure; at the same time, the plug welding process makes the overall structure more compact, avoiding the corrosion risk caused by exposed fasteners, and is suitable for high temperature, high pressure and strong corrosive medium environment, significantly prolonging the service life of the flange assembly.

[0031] It should be noted that the first flange 1 and the second flange 7 are made of steel material, while the first zirconium sealing surface 2, the second zirconium sealing surface 3 and the liner pipe 5 are made of zirconium material, which is fixed by the zirconium screw 4 and reliably connected in the wedge plug welding area 6, avoiding the process difficulty caused by direct welding of zirconium material and steel flange.

[0032] Optionally, the screw 4 is made of zirconium, and the size of the screw 4 is selected according to the connection and sealing requirements of the first flange 1 and the second flange 7.

[0033] In this embodiment, the screw 4 made of zirconium material is matched with the structure of the second zirconium sealing surface 3, ensuring excellent corrosion resistance in a strong corrosive medium environment and avoiding electrochemical corrosion problems caused by material differences. At the same time, the zirconium screw can be accurately selected according to the sealing grade of the flange connection, the pressure and temperature conditions and the structure size, ensuring the stability and reliability of the overall sealing system, especially suitable for high-end equipment fields such as chemical industry and petrochemical industry which have strict sealing requirements.

[0034] Optionally, the length of the screw hole is 1.5 to 2 times the nominal diameter of the screw 4. This design ensures that the screw 4 has enough engagement length when bearing the working load, effectively preventing unclamping or breaking and improving the reliability of the connection; at the same time, combined with the characteristics of zirconium material, it avoids stress concentration caused by too short engagement, further ensuring the long-term stable operation of the sealing structure under high temperature, high pressure and corrosive medium.

[0035] Optionally, before the plug welding seal, the bevel within 50mm of the plug welding area needs to be mechanically cleaned to remove the surface oxide film and degrease. This treatment ensures the welding area is clean and avoids oxide or grease contamination affecting the weld quality.

[0036] Optionally, the plug seal is achieved using tungsten inert gas (TIG) welding, and no post-weld heat treatment is performed after the plug weld is completed. Using TIG welding ensures a stable welding process, good weld formation, and, combined with the properties of zirconium, effectively controls heat input and reduces the tendency for intergranular corrosion. The absence of post-weld heat treatment avoids damaging the original corrosion resistance of the zirconium material, ensuring the long-term reliability of the welded joint under harsh operating conditions.

[0037] During welding, the welding current is controlled between 160A and 180A, and the interpass temperature is strictly controlled below 60℃ to ensure effective cooling of the welding area and prevent overheating that could lead to grain coarsening or localized deformation. Argon gas with a purity of not less than 99.999% is used as the shielding gas to effectively isolate the weld from air, prevent oxidation of the weld metal, and ensure the weld's density and corrosion resistance. After welding, the surface of the plug weld area undergoes 100% PT testing and is rated as Grade I qualified according to NB / T47013.5-2015 standard, ensuring the absence of surface defects.

[0038] Optionally, a sealing gasket is provided in both the first zirconium sealing surface 2 and the second zirconium sealing surface 3, and the sealing gasket is a spiral wound gasket.

[0039] In this embodiment, the spiral wound gasket is made of zirconium strip and fluoride filler material alternately wound, and the inner and outer rings and metal strips can be made of SB551, R50702, or other corrosion-resistant materials. It possesses both good resilience and corrosion resistance, effectively compensating for minor deformations of the flange surface under high temperature and pressure conditions, ensuring a long-lasting and reliable seal. The gasket's structural design ensures a tight fit with the zirconium sealing surface, avoiding stress concentration and preventing interfacial corrosion caused by media penetration.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A zirconium material inlet reducing integral flange and its liner structure, comprising a liner (5), a first flange (1), and a second flange (7), characterized in that: The first flange (1) and the second flange (7) are fitted onto the surface of the liner (5), and the first flange (1) and the second flange (7) are connected and fixed by tightening bolts (8). A first zirconium sealing surface (2) is provided between the end of the first flange (1) away from the second flange (7) and the liner (5), and a sealing assembly is provided between the connection surface of the second flange (7) and the first flange (1). The sealing assembly includes a sealing groove on the opposite surfaces of the first flange (1) and the second flange (7). A second zirconium sealing surface (3) is embedded in the sealing groove. A screw hole is provided in the first flange (1) through the second zirconium sealing surface (3) and connected to it. A screw (4) is screwed into the screw hole to press and fix the second zirconium sealing surface (3) in the sealing groove.

2. The zirconium-made material inlet reducing integral flange and its liner structure according to claim 1, characterized in that: After the screw (4) is tightened, it forms a wedge-shaped plug welding area (6) with the surface of the second zirconium sealing surface (3). The wedge-shaped plug welding area (6) is sealed by plug welding, so that the screw (4) and the second zirconium sealing surface (3) form an integrated fixing structure.

3. The zirconium material inlet reducing integral flange and its liner structure according to claim 1, characterized in that: The screw (4) is made of zirconium, and the screw (4) is selected according to the connection and sealing requirements of the first flange (1) and the second flange (7).

4. The zirconium-made material inlet reducing integral flange and its liner structure according to claim 1, characterized in that: The length of the screw hole is 1.5 to 2 times the nominal diameter of the screw (4).

5. The zirconium material inlet reducing integral flange and its liner structure according to claim 2, characterized in that: Before the plug welding seal, the bevel within 50mm of the plug welding area needs to be mechanically cleaned to remove the surface oxide film and degrease.

6. The zirconium material inlet reducing integral flange and its liner structure according to claim 5, characterized in that: The plug welding seal is performed using tungsten inert gas welding, and no post-weld heat treatment is performed after the plug welding is completed.

7. The zirconium material inlet reducing integral flange and its liner structure according to claim 1, characterized in that: Both the first zirconium sealing surface (2) and the second zirconium sealing surface (3) are provided with sealing gaskets.

8. The zirconium-made material inlet reducing integral flange and its liner structure according to claim 7, characterized in that: The sealing gasket is a spiral wound gasket.

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