Welding-free flange connecting device

Abstract

The utility model discloses a welding-free flange connecting device which comprises a pipeline, a connecting flange and a hoop sleeve, the connecting flange and the hoop sleeve are arranged on the pipeline in a sleeved mode, a hoop sleeve clamping groove is formed between the inner wall of the connecting flange and the outer wall of the pipeline, the hoop sleeve is tightly inserted in the hoop sleeve clamping groove, teeth are arranged on the inner wall of the hoop sleeve and abut against the outer wall of the pipeline, and the hoop sleeve is connected with the connecting flange. The flange has the advantages of simple structure, no need of welding, convenience in assembly and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of pipeline flange connection, in particular to a welding-free flange connection device. Background Art

[0002] Pipelines and pipes, pipes and valves are usually connected by flanges, and the connected flanges are fixed by threaded connections of bolts and nuts. In the prior art, the flanges on the pipes are generally fixed on the pipes by welding. The problems with welding are: first, the flange welding process is complicated, which requires high welding skills of the operators and takes a long time to operate; second, the welding process is likely to cause cracks, deformation and other problems in the pipes, affecting the working effect of the pipes; third, welding deviations are prone to occur, and after welding, the flange end face is not perpendicular to the pipe axis, resulting in loose flange connection and easy leakage of the medium in the pipe; fourth, the pipe is directly welded with the flange, and one end of the pipe flange can no longer be cut or modified, which has great limitations in use. Utility Model Content

[0003] The utility model aims to solve the above-mentioned deficiencies of the prior art and provide a welding-free flange connection device which has a simple structure, does not require flange welding, and is easy to assemble.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A welding-free flange connection device, characterized in that it comprises a pipeline, a connection flange and a hoop sleeve, wherein the connection flange and the hoop sleeve are sleeved on the pipeline, and a hoop sleeve groove is formed between the inner wall of the connection flange and the outer wall of the pipeline;

[0006] The hoop is inserted tightly into the hoop slot, and the inner wall of the hoop is provided with teeth, which abut against the outer wall of the pipe;

[0007] Through the cooperation of the connecting flange and the hoop, the connecting flange can be limited without being welded on the pipeline, the structure is simple, and the installation and disassembly are convenient.

[0008] The inner wall of the connecting flange of the utility model is provided with a conical guiding inclined surface 1, and a hoop clamping groove for the hoop to be inserted is formed between the conical guiding inclined surface 1 and the outer wall of the pipeline;

[0009] The outer wall of the hoop is provided with a second conical guiding slope, which is slidably matched with the first conical guiding slope. The hoop is tightly inserted into the hoop slot through the sliding match between the second conical guiding slope and the first conical guiding slope. The setting of the conical guiding slope facilitates the insertion of the hoop and the connecting flange.

[0010] The tooth of the utility model comprises a vertical surface and an inclined surface, wherein the vertical surface is perpendicular to the axis of the hoop sleeve, and the vertical surface and the inclined surface are connected to form a sharp angle of the tooth, and the sharp angle abuts against the outer wall of the pipe;

[0011] The sharp corners are pressed against the outer wall of the pipe to ensure the radial clamping effect. After the connecting flange and the clamp are clamped, the clamp will not be displaced. The single-sided inclined structure of the teeth makes the sharp corners have sharper edges, ensuring that the pipe can be better clamped. When the length of the teeth from the root to the sharp corner is constant, the acute angle formed by the vertical surface of the teeth and the inclined surface is set to be smaller than the acute angle formed by the connection of the two inclined surfaces, and the clamping effect is better.

[0012] The teeth of the utility model are arranged in an annular manner along the inner wall of the hoop sleeve, and a plurality of teeth are arranged closely in the axial direction;

[0013] The roots of the teeth form fillets at the junctions of adjacent teeth;

[0014] A plurality of tooth tip angles are connected along the axial direction to form a tooth tip connection line, and the tooth tip connection line is arranged to be inclined from rear to front and inward relative to the axis of the hoop;

[0015] Arranging a plurality of teeth can further ensure that it can be pressed tightly on the pipe. The roots of the teeth form fillets at the connection points of adjacent teeth, making the teeth stronger and less prone to metal fatigue. The connecting line of the tooth tips is inclined from back to front and inward relative to the axis of the hoop, so that when the rear section of the hoop shrinks and deforms inward, the force does not only act on the teeth at the rear end, but is shared by more teeth, further improving the strength of the teeth.

[0016] The end surface of the hoop sleeve of the utility model that extends into the hoop sleeve slot is provided with an open groove that penetrates inside and outside along the axial direction;

[0017] The bottom of the opening groove is connected to an adjustment groove which is arranged to penetrate inside and outside, the adjustment groove is connected to the opening groove, and the circumferential dimension of the adjustment groove is larger than the circumferential dimension of the opening groove;

[0018] The setting of the open groove facilitates the deformation of the hoop, so that the hoop can be clamped with the connecting flange and pressed against the outer wall of the pipe. The setting of the adjustment groove further facilitates the deformation of the hoop and clamping it in the hoop clamping groove, and the teeth are pressed against the outer wall of the pipe.

[0019] The utility model also includes a limiting sleeve, the front end of the inner wall of the limiting sleeve extends inward to form a limiting boss, the connecting flange, the hoop sleeve and the limiting sleeve are sequentially sleeved on the pipeline, the outer end face of the limiting boss conflicts with the fixed flange, the inner end face of the limiting boss conflicts with the front end face of the pipeline, the rear end of the limiting sleeve conflicts with the hoop sleeve, and the connecting flange and the fixed flange are threadedly connected and fixed by bolts and nuts; when the connecting flange on the pipeline is docked and installed with the valve or the fixed flange on another pipeline, the position of the hoop sleeve and the connecting flange is limited by the limiting sleeve.

[0020] A hoop limiting groove is formed between the rear end of the limiting sleeve inner wall and the outer wall of the pipeline, and an O-ring is also sleeved on the pipeline. The O-ring is arranged in the hoop limiting groove, and one end of the hoop away from the hoop clamping groove is inserted into the hoop limiting groove. The setting of the hoop limiting groove realizes axial limitation of the hoop, which is convenient for assembly, and the O-ring effectively prevents leakage of the medium in the pipeline.

[0021] The limit sleeve of the utility model comprises a limit sleeve front section, a limit sleeve middle section 2 and a limit sleeve rear section, wherein the limit sleeve front section, the limit sleeve middle section 2 and the limit sleeve rear section are arranged and fixed in sequence from front to back and are coaxially arranged, and the limit sleeve front section forms a limit boss extending inwardly, and when the limit sleeve is sleeved on the pipeline, the front end face of the limit sleeve conflicts with the inner end face of the fixed flange, and the front end face of the pipeline is limited by the limit boss;

[0022] The second inner wall of the middle section of the limiting sleeve is provided with a conical inclined surface arranged in a circumferential ring, and the large diameter end of the conical inclined surface is connected to the front end of the inner wall of the rear section of the limiting sleeve;

[0023] A hoop limiting groove is formed between the inner wall of the rear section of the limiting sleeve, the inner walls of the middle section of the limiting sleeve and the outer wall of the pipeline.

[0024] The front section of the hoop sleeve of the utility model is inserted between the rear section of the limiting sleeve and the outer wall of the pipeline, the inner diameter of the front section of the hoop sleeve matches the outer diameter of the pipeline, and the outer diameter of the front section of the hoop sleeve matches the inner diameter of the rear section of the limiting sleeve;

[0025] The connection between the front end of the outer wall of the hoop and the front end surface of the hoop is set as a rounded corner, and the rounded corner abuts against the conical inclined surface of the second middle section of the limiting sleeve;

[0026] The O-shaped sealing ring is set between the outer wall of the pipeline and the tapered inclined surfaces of the second inner wall of the middle section of the limiting sleeve, and the O-shaped sealing ring is tightly pressed against the front end surface of the hoop sleeve, the tapered inclined surface, and the outer wall of the pipeline;

[0027] By setting the fillet to conflict with the tapered slope, it can ensure that the connecting flange and the fixed flange have good rigidity after axial locking by bolts, and can also ensure that the hoop and the limit sleeve can be automatically centered under a certain axial offset, thereby ensuring a reliable seal. Under the extrusion of the axial force of the hoop and the tapered slope, the radial inward force generated enables the O-ring to fit tightly against the outer wall of the pipe, further ensuring the sealing effect.

[0028] The limit sleeve of the utility model also includes a limit sleeve middle section 1, the limit sleeve front section, the limit sleeve middle section 1, the limit sleeve middle section 2, and the limit sleeve rear section are arranged and fixed in sequence from front to back and are coaxially arranged, the limit sleeve front section forms a limit boss extending inward, the inner diameter of the limit sleeve middle section 1 matches the outer diameter of the pipeline, and an annular pipeline limit end face is formed between the inner wall of the limit sleeve front section and the inner wall of the limit sleeve middle section 1. When the limit sleeve is sleeved on the pipeline, the front end face of the limit sleeve conflicts with the inner end face of the fixed flange, and the pipeline limit end face is against the front end face of the pipeline;

[0029] The tapered inclined surface of the second middle section of the limiting sleeve has a small diameter end connected to the rear end of the inner wall of the first middle section of the limiting sleeve, and a large diameter end connected to the front end of the inner wall of the rear section of the limiting sleeve, further ensuring the stability of the matching between the limiting sleeve and the pipeline.

[0030] The beneficial effects of the utility model are as follows: through the cooperation between the connecting flange and the hoop, the connecting flange can be limited without being welded on the pipeline, the structure is simple, and the installation and disassembly are convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0032] Figure 2 It is a schematic diagram of the overall structure of the utility model from another angle.

[0033] Figure 3 It is the front view of the overall structure (with the fixing flange hidden) of the utility model.

[0034] Figure 4 yes Figure 3 Middle AA section view.

[0035] Figure 5 It is a schematic diagram of the hoop structure of the utility model.

[0036] Figure 6 It is a schematic structural diagram of the hoop sleeve of the utility model from another angle.

[0037] Figure 7 It is a front view of a hoop sleeve of the utility model.

[0038] Figure 8 yes Figure 7 Middle BB section view.

[0039] Fig. 9 yes Figure 8 Enlarged view of point C in the middle.

[0040] Fig.10 It is a schematic diagram of the structure of the limit sleeve of the utility model.

[0041] Fig.11 It is the front view of the limiting sleeve of the utility model.

[0042] Fig.12 yes Fig.11 Middle DD section view.

[0043] Reference numerals: pipeline-1;

[0044] Connecting flange-2, conical guide slope-201;

[0045] Fixed flange-3;

[0046] Bolts - 4;

[0047] Nut-5;

[0048] Hoop 6, hoop front section outer wall 6011, hoop front section inner wall 6012, fillet 1 6013, hoop middle section 602, conical guide inclined surface 2 6031, tooth 6032, vertical surface 60321, inclined surface 60322, sharp corner 60323, fillet 2 60324, tooth tip connecting line 60325, opening slot 604, adjustment slot 605;

[0049] Limiting sleeve 7, inner wall of the front section of the limiting sleeve 701, inner wall of the middle section 1 of the limiting sleeve 702, inner wall of the middle section 2 of the limiting sleeve 703, inner wall of the rear section of the limiting sleeve 704, and the pipe limiting end face 705;

[0050] O-rings-8. DETAILED DESCRIPTION

[0051] The utility model is described below in conjunction with the accompanying drawings and embodiments.

[0052] As shown in the accompanying drawings, a welding-free flange connection device comprises a pipeline 1, a connecting flange 2 and a hoop 6, wherein the connecting flange 2 and the hoop 6 are sequentially sleeved on the pipeline 1, and a hoop slot is formed between the inner wall of the connecting flange 2 and the outer wall of the pipeline 1;

[0053] The hoop 6 is inserted into the hoop slot, and the inner wall of the hoop is provided with teeth 6032, and the teeth 6032 abut against the outer wall of the pipe 1;

[0054] The connection flange 2 and the collar 6 cooperate, and the connection flange 2 does not need to be welded on the pipeline 1 to achieve the connection flange 2 limit, the structure is simple, and the installation and disassembly are convenient.

[0055] In this embodiment, the connecting flange 2 is sleeved on the pipeline 1, and a fixing flange 3 is fixed on a valve or another pipeline connected to the pipeline.

[0056] The inner wall of the connecting flange 2 is provided with a conical guide slope 201 arranged in an annular manner along the circumference of the inner wall, and a hoop clamping groove for inserting the hoop 6 is formed between the conical guide slope 201 and the outer wall of the pipe 1. In this embodiment, the front end of the inner wall of the connecting flange 2 is the large diameter end of the conical guide slope 201, and the rear end is the small diameter end of the conical guide slope 201.

[0057] The hoop 6 comprises a hoop front section, a hoop middle section 602 and a hoop rear section, wherein the hoop front section, the hoop middle section 602 and the hoop rear section are arranged and fixed in sequence from front to rear and are coaxially arranged. In this embodiment, the hoop front section, the hoop middle section 602 and the hoop rear section are integrally formed, and teeth 6032 are fixed on the inner wall of the hoop rear section, and the teeth 6032 are provided with a tip, and the tip of the teeth 6032 abuts against the outer wall of the pipe 1, and is pressed against the outer wall of the pipe by the tip of the teeth to ensure the pressing effect, and the teeth 6032 are arranged in an annular shape along the circumferential inner wall of the hoop rear section, and a plurality of annular teeth 6032 are provided, and the plurality of teeth 6032 are arranged closely along the axial direction of the hoop 6 to further ensure that it can be pressed on the pipe 1.

[0058] In this embodiment, the tip of the tooth 6032 is set as a sharp angle 60323, and the sharp angle 60323 is against the outer wall of the pipe 1; the sharp angle 60323 is pressed against the outer wall of the pipe 1 to ensure the radial compression effect, and the hoop 6 will not be displaced after the connecting flange 2 and the hoop 6 are clamped; in this embodiment, the tip of the tooth 6032 is set as a sharp angle 60323, and it can also be set as a rounded angle or a flat angle as needed;

[0059] In this embodiment, the tooth 6032 includes a vertical surface 60321 and an inclined surface 60322, wherein the vertical surface 60321 is perpendicular to the axis of the hoop 6, and the vertical surface 60321 and the inclined surface 60322 are connected to form a sharp angle 60323 of the tooth 6032; the single-sided inclined structure of the tooth 6032 makes the tip have a sharper edge, ensuring that the pipe 1 can be better clamped. When the length of the tooth 6032 from the root to the tip is constant, the acute angle formed by the connection of the vertical surface of the tooth and the inclined surface is set to be smaller than the acute angle formed by the connection of the two inclined surfaces, and the clamping effect is better;

[0060] The root of the tooth 6032 forms a fillet 60324 at the connection between adjacent teeth, making the tooth 6032 stronger and less prone to metal fatigue. Fig. 9It can be seen that the vertical surface of the rear tooth is connected to the inclined surface of the front tooth, and a fillet is formed at the connection;

[0061] The tips of several teeth 6032 are connected axially to form a tooth tip connection line 60325, and the tooth tip connection line 60325 is arranged to be inclined inward from rear to front relative to the axis of the hoop 6; when the rear section of the hoop 6 shrinks and deforms inward, the force does not only act on the teeth 6032 at the rear end, but is shared by more teeth 6032, thereby further improving the strength of the teeth 6032.

[0062] The outer wall of the rear section of the hoop 6 is set as a conical guide slope 2 6031 arranged in a circumferential ring direction. The front end of the conical guide slope 2 6031 is a large diameter end, and the rear end is a small diameter end. The size of the conical guide slope 2 6031 matches the size of the conical guide slope 1 201. The conical guide slope 2 6031 is slidably matched with the conical guide slope 1 201, and the rear section of the hoop is tightly inserted in the hoop slot.

[0063] The rear end surface of the hoop is provided with an open groove 604 that penetrates the inner and outer walls of the hoop in the axial direction; the setting of the open groove 604 can ensure that the hoop 6 is inserted into the hoop clamping groove and squeezed tightly, and the teeth 6032 can be pressed tightly against the outer wall of the pipe 1. In this embodiment, the size of the rear section of the hoop is set to be larger than the size of the hoop clamping groove, and the open groove is set. During the process of inserting the rear section of the hoop into the hoop clamping groove through the guiding effect of the conical guide inclined surface 1 and the conical guide inclined surface 2, the rear section of the hoop can be clamped in the hoop clamping groove through deformation, thereby realizing the limiting of the hoop and the connecting flange.

[0064] The hoop 6 is provided with a plurality of opening grooves 604 at intervals along the circumferential direction, which further facilitates the deformation of the hoop 6 .

[0065] The opening groove 604 extends forward along the axial direction of the hoop to the middle section 602 of the hoop, and the bottom of the opening groove 604 is connected with an adjustment groove 605 which is arranged inside and outside, and the adjustment groove 605 is connected with the opening groove 604, and the circumferential opening size of the adjustment groove 605 is larger than the circumferential opening size of the opening groove 604, so that the hoop 6 can be deformed and clamped in the hoop clamping groove, further ensuring that the hoop has a larger tightening space, and ensuring the radial clamping force of the teeth 6032.

[0066] This embodiment also includes a limiting sleeve 7, the connecting flange 2, the hoop 6, and the limiting sleeve 7 are sequentially sleeved on the pipeline, the limiting sleeve 7 includes a limiting sleeve front section, a limiting sleeve middle section 1, a limiting sleeve middle section 2, and a limiting sleeve rear section, the limiting sleeve front section, the limiting sleeve middle section 1, the limiting sleeve middle section 2, and the limiting sleeve rear section are sequentially arranged and fixed from front to back and coaxially arranged, in this embodiment, the limiting sleeve front section and the limiting sleeve middle section 1, the limiting sleeve middle section 2, and the limiting sleeve rear section are integrally formed, The inner diameter of the front section of the limiting sleeve is smaller than the inner diameter of the middle section of the limiting sleeve, and the front section of the limiting sleeve forms a limiting boss extending inwardly. An annular pipeline limiting end face 705 is formed between the inner wall 701 of the front section of the limiting sleeve and the inner wall 702 of the middle section of the limiting sleeve. When the limiting sleeve 7 is sleeved on the pipeline 1, the front end face of the limiting sleeve contacts the inner end face of the fixed flange, and the pipeline limiting end face 705 contacts the front end face of the pipeline. The inner diameter of the middle section of the limiting sleeve matches the outer diameter of the pipeline.

[0067] The second inner wall 703 of the middle section of the limiting sleeve is configured as a conical inclined surface arranged in a circumferential ring direction, the small diameter end of the conical inclined surface is connected to the rear end of the first inner wall 702 of the middle section of the limiting sleeve, and the large diameter end is connected to the front end of the inner wall 704 of the rear section of the limiting sleeve;

[0068] A hoop limiting groove is formed between the inner wall 704 of the rear section of the limiting sleeve and the second inner wall 703 of the middle section of the limiting sleeve and the outer wall of the pipe 1, and the front section of the hoop is inserted into the hoop limiting groove. The inner diameter of the front section of the hoop matches the outer diameter of the pipe, and the outer diameter of the front section of the hoop matches the inner diameter of the rear section of the limiting sleeve; the axial limitation of the hoop is realized, which is convenient for assembly.

[0069] The pipeline 1 is also sleeved with an O-ring 8, which is arranged in the limiting groove of the hoop. In this embodiment, the O-ring is arranged between the outer wall of the pipeline and the conical inclined surface of the inner wall 703 of the second middle section of the limiting sleeve. The O-ring 8 is simultaneously pressed against the front end face of the hoop, the conical inclined surface of the second middle section of the limiting sleeve, and the outer wall of the pipeline; under the extrusion of the axial force of the hoop and the conical inclined surface, the radial inward component of force generated by the O-ring enables the O-ring to be tightly attached to the outer wall of the pipeline, further ensuring the sealing effect and preventing leakage of the medium in the pipeline.

[0070] The connection between the front end of the outer wall of the hoop 6 and the front end face of the hoop is set as a rounded corner 6013, and the rounded corner 6013 is against the conical inclined surface; by setting the rounded corner 6013 to abut against the conical inclined surface, it can ensure that the connecting flange 2 and the fixing flange 3 have good rigidity after axial locking by the bolt 4, and can also ensure that the hoop 6 and the limit sleeve 7 can be automatically centered under a certain axial offset, thereby further ensuring the sealing effect.

[0071] When the utility model is used:

[0072] 1. During installation, the connecting flange 2, the hoop 6, the O-ring 8 and the limiting sleeve 7 are sequentially sleeved on the front end of the pipe 1, the pipe limiting end face 705 of the limiting sleeve 7 is pressed against the front end face of the pipe 1, the position of the hoop 6 is adjusted according to the position of the limiting sleeve 7, the front section of the hoop is inserted into the hoop limiting groove, the O-ring 8 is located between the tapered inclined surface and the outer wall of the pipe 1, and is pressed against the front end face of the hoop and the tapered inclined surface to achieve sealing;

[0073] 2. Move the connecting flange 2 axially forward, so that the rear section of the collar is deformed along the conical guide slope 201 and inserted into the collar groove. At this time, the tip of the teeth 6032 is radially pressed against the outer wall of the pipe 1.

[0074] 3. A plurality of bolt holes are provided on the connecting flange 2 and the fixing flange 3 at intervals along the circumferential direction. Bolts 4 pass through the bolt holes on the connecting flange 2 and the fixing flange 3 in sequence. Nuts 5 are sleeved on both ends of the bolts 4. The nuts 5 are threadedly connected with the bolts 4. One nut 5 is pressed against the outer end surface of the connecting flange 2, and the other nut 5 is pressed against the outer end surface of the fixing flange 3 to achieve the connection between the connecting flange 2 and the fixing flange 3. In this process, the fillet 1 6013 on the hoop is pressed against the conical inclined surface of the middle section 2 of the limit sleeve, which can be automatically centered.

[0075] 4. When it is necessary to cut or modify the pipeline 1, loosen the nut 5, pull out the bolt 4, move the connecting flange 2 backward, so that the rear section of the hoop sleeve can be disengaged from the hoop sleeve slot, and then remove the limit sleeve 7, hoop sleeve 6, and connecting flange 2 in sequence along the axial direction of the pipeline 1.

Claims

1. A welding-free flange connection device, characterized in that: It comprises a pipeline, a connecting flange and a hoop sleeve, wherein the connecting flange and the hoop sleeve are sleeved on the pipeline, and a hoop sleeve groove is formed between the inner wall of the connecting flange and the outer wall of the pipeline; The hoop is tightly inserted into the hoop slot, and the inner wall of the hoop is provided with teeth, which abut against the outer wall of the pipeline.

2. A welding-free flange connection device according to claim 1, characterized in that: The inner wall of the connecting flange is provided with a conical guiding inclined surface 1, and a hoop clamping groove for the hoop to be inserted is formed between the conical guiding inclined surface 1 and the outer wall of the pipeline; The outer wall of the hoop is provided with a second conical guiding slope, which is slidably matched with the first conical guiding slope. The hoop is tightly inserted into the hoop slot through the sliding match between the second conical guiding slope and the first conical guiding slope.

3. A welding-free flange connection device according to claim 1 or 2, characterized in that: The tooth comprises a vertical surface and an inclined surface, wherein the vertical surface is perpendicular to the axis of the hoop sleeve, and the vertical surface and the inclined surface are connected to form a sharp corner of the tooth, and the sharp corner abuts against the outer wall of the pipe.

4. The welding-free flange connection device according to claim 3, characterized in that: The teeth are arranged in an annular manner along the inner wall of the hoop sleeve, and a plurality of the teeth are arranged closely in the axial direction; The roots of the teeth form fillets at the junctions of adjacent teeth; A plurality of tooth tip angles are connected along the axial direction to form a tooth tip portion connection line, and the tooth tip portion connection line is arranged to be inclined from rear to front and inward relative to the axis of the hoop sleeve.

5. A welding-free flange connection device according to claim 1, 2 or 4, characterized in that: An open groove is axially provided on the end surface of the hoop that extends into the hoop slot; The bottom of the opening groove is connected with an adjustment groove which is arranged to penetrate inside and outside, the adjustment groove is connected with the opening groove, and the circumferential dimension of the adjustment groove is larger than the circumferential dimension of the opening groove.

6. A welding-free flange connection device according to claim 1, 2 or 4, characterized in that: It also includes a limiting sleeve, wherein the connecting flange, the hoop sleeve and the limiting sleeve are sequentially sleeved on the pipe, the front end of the inner wall of the limiting sleeve extends inward to form a limiting boss, the outer end face of the limiting boss conflicts with the fixed flange, the inner end face of the limiting boss conflicts with the front end face of the pipe, the rear end of the limiting sleeve conflicts with the hoop sleeve, and the connecting flange and the fixed flange are threadedly connected and fixed by bolts and nuts.

7. The welding-free flange connection device according to claim 6, characterized in that: A hoop limiting groove is formed between the rear end of the limiting sleeve inner wall and the outer wall of the pipe. An O-ring is also sleeved on the pipe. The O-ring is arranged in the hoop limiting groove. One end of the hoop away from the hoop clamping groove is inserted into the hoop limiting groove.

8. The welding-free flange connection device according to claim 7, characterized in that: The limiting sleeve comprises a limiting sleeve front section, a limiting sleeve middle section 2 and a limiting sleeve rear section, wherein the limiting sleeve front section, the limiting sleeve middle section 2 and the limiting sleeve rear section are arranged and fixed in sequence from front to back and are coaxially arranged, and the limiting sleeve front section forms a limiting boss extending inwardly, and when the limiting sleeve is sleeved on the pipeline, the front end face of the limiting sleeve conflicts with the inner end face of the fixed flange, and the front end face of the pipeline is limited by the limiting boss; The second inner wall of the middle section of the limiting sleeve is provided with a conical inclined surface arranged in a circumferential ring, and the large diameter end of the conical inclined surface is connected to the front end of the inner wall of the rear section of the limiting sleeve; A hoop limiting groove is formed between the inner wall of the rear section of the limiting sleeve, the inner walls of the middle section of the limiting sleeve and the outer wall of the pipeline.

9. The welding-free flange connection device according to claim 8, characterized in that: The front section of the hoop is inserted between the rear section of the limiting sleeve and the outer wall of the pipeline, the inner diameter of the front section of the hoop matches the outer diameter of the pipeline, and the outer diameter of the front section of the hoop matches the inner diameter of the rear section of the limiting sleeve; The connection between the front end of the outer wall of the hoop and the front end surface of the hoop is set as a rounded corner, and the rounded corner abuts against the conical inclined surface of the second middle section of the limiting sleeve; The O-shaped sealing ring is set between the outer wall of the pipeline and the conical inclined surfaces of the two inner walls of the middle section of the limiting sleeve. The O-shaped sealing ring is tightly pressed against the front end surface of the hoop, the conical inclined surface and the outer wall of the pipeline.

10. A welding-free flange connection device according to claim 8 or 9, characterized in that: The limiting sleeve also includes a limiting sleeve middle section 1, the limiting sleeve front section, the limiting sleeve middle section 1, the limiting sleeve middle section 2, and the limiting sleeve rear section are arranged and fixed in sequence from front to back and are coaxially arranged, the limiting sleeve front section forms a limiting boss extending inward, the inner diameter of the limiting sleeve middle section 1 matches the outer diameter of the pipeline, and an annular pipeline limiting end face is formed between the inner wall of the limiting sleeve front section and the inner wall of the limiting sleeve middle section 1, and when the limiting sleeve is sleeved on the pipeline, the front end face of the limiting sleeve conflicts with the inner end face of the fixed flange, and the pipeline limiting end face conflicts with the front end face of the pipeline; The small diameter end of the tapered inclined surface of the middle section 2 of the limiting sleeve is connected to the rear end of the inner wall of the middle section 1 of the limiting sleeve, and the large diameter end is connected to the front end of the inner wall of the rear section of the limiting sleeve.

Images