Socket crimping type double-layer pipe joint and pipe connecting structure

Abstract

The utility model discloses a socket crimping type double-layer pipe joint and a pipe connecting structure, and belongs to the technical field of pipeline connection, the pipe connecting structure comprises a pipe and a socket crimping type double-layer pipe joint, the socket crimping type double-layer pipe joint comprises a connector, the connector comprises an outer end and an inner end, the outer end of the core sleeve is provided with a socket crimping ring groove formed by the shell and the core sleeve, a special-shaped sealing ring is arranged in the socket crimping ring groove and comprises a sealing ring body and a radial flange integrally formed at the end of the sealing ring body, the core sleeve is fixedly sleeved with the sealing ring body, and the radial flange is located at the bottom of the socket crimping ring groove. The spigot-and-socket gap is formed between the sealing ring body and the shell, the end of the pipe is inserted into the spigot-and-socket gap and abuts against the radial flange, the pipe and the spigot-and-socket compression joint type double-layer pipe joint are sealed and fixed through a compression joint tool, the problems that the sealing ring is extruded and disengaged from a compression joint port and sealing fails are solved, and the spigot-and-socket compression joint type double-layer pipe joint has the advantage of being high in sealing performance.

Description

Technical Field

[0001] This utility model belongs to the field of pipeline connection technology, specifically relating to a socket-type double-layer pipe joint and pipe connection structure. Background Technology

[0002] In recent years, stainless steel pipes connected by cold extrusion have been increasingly used in the field of pipe connection technology due to their advantages such as no threading, no welding, and convenient and quick installation. Currently, the publicly available and mature cold extrusion connection structures for steel pipes mainly include press-fit connections, ring press connections, and socket press connections. However, all three connection structures have certain technical problems, as follows:

[0003] The press-fit connection structure, based on the connection specifications on page 24 of the National Building Standard Design Atlas "22S407-2: Installation of Thin-Walled Stainless Steel Pipes for Building Water Supply" published by the China Academy of Building Research, uses socket fittings with special sealing rings to connect pipes. A crimping tool is used to press the pipe ends together to achieve sealing and fastening. It forces the connecting fittings and pipes into a hexagonal shape, forming a square recess. The rigidity of the metal increases the frictional resistance between the pipe and fitting at the six corners of the hexagon, achieving a lock-in effect. Simultaneously, the O-ring seal on the fitting socket provides a seal. While this structure possesses certain tensile strength and sealing performance, because the connection method creates a single-layer structure, the strength of the single-layer structure itself and the six corners are not subjected to sufficient compressive force during the pressing and locking process, thus affecting its sealing performance.

[0004] The ring-press connection structure is a mechanical pipe connection method based on the connection specifications on page 33 of the National Building Standard Design Atlas "22S407-2: Installation of Thin-Walled Stainless Steel Pipes for Building Water Supply" published by the China Academy of Building Research. It uses a crimping tool to press the pipe fitting and a cylindrical rubber sealing ring together with the pipe material inwards along the circumference to form a single unit. The biggest advantage of this connection method is that it replaces the O-ring used in press-fit connections with a cylindrical rubber sealing ring. The locking structure formed during compression is more stable than that of press-fit connections. However, this connection structure is still greatly affected by the strength of the product's own materials. When the pressure inside the pipe increases, there is a risk that the cylindrical rubber sealing ring may be squeezed out from the crimping port, which will directly lead to seal failure and thus limit the pipe's pressure-bearing capacity.

[0005] The socket-crimped joint structure is based on the connection specifications on page 37 of the National Building Standard Design Atlas "22S407-2 Installation of Thin-Walled Stainless Steel Pipes for Building Water Supply". It uses a crimping tool to press the fitting and pipe together circumferentially. Figure 8As shown, the crimping tool 7 typically includes a left crimping groove and a right crimping groove. A cavity 71 is located between the left and right crimping grooves. The horizontal surface of the cavity 71 is a straight horizontal line. A limiting step 72 for limiting and fixing the end face of the pipe fitting is also provided at the end of the right crimping groove 1. The socket crimping structure includes an outer jacket and a core sleeve. The sealing material between the outer jacket and the core sleeve is changed to anaerobic adhesive. Although this connection structure has higher tensile strength and sealing performance after compression and locking, because the outer jacket and core sleeve structure are not independently sealed, the core sleeve only serves a supporting function. Furthermore, the sealant is a fluid sealing material, which can cause the sealant to overflow into the pipe after crimping, blocking the pipe and its auxiliary equipment. Simultaneously, because the outer jacket and core sleeve of this connection structure are not completely sealed, the anaerobic adhesive is prone to failure to solidify upon contact with an aerobic environment, ultimately leading to loss of sealing performance and reduced pressure resistance.

[0006] Therefore, there is an urgent need to design a new type of pipe fitting and pipe connection structure to improve the sealing performance of the connected pipes and thus enhance their pressure resistance. Utility Model Content

[0007] The purpose of this invention is to solve the above-mentioned problems existing in the prior art and to provide a socket-type double-layer pipe joint and pipe connection structure. This invention uses a shell and a core sleeve to form a socket-type pressing ring groove, and the sealing ring body and radial flange of the irregular sealing ring form a cooperative seal in the socket-type pressing ring groove. This effectively solves the technical problems of the sealing ring being squeezed out of the pressing port and the sealing failure in the existing pipe connection technology, and greatly improves the sealing performance of the pipe connection.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0009] On one hand, this utility model provides a socket-press type double-layer pipe joint, including a connector and a pipe cap. The connector includes an inner end and an outer end. The inner end is fixedly connected to the pipe cap. The outer end is provided with a socket-pressing ring groove formed by a shell and a core sleeve. A special-shaped sealing ring is provided in the socket-pressing ring groove. The special-shaped sealing ring includes a sealing ring body and a radial flange integrally formed at the end of the sealing ring body. The sealing ring body is fixedly sleeved on the core sleeve. The radial flange is located at the bottom of the socket-pressing ring groove. The shell and the sealing ring body form a socket gap with the radial flange as the pipe end face sealing structure.

[0010] The outer shell and the core sleeve are welded and fixed together, and the tube cap is welded to the inner end of the connector.

[0011] The inner end face of the outer shell and the inner end face of the core sleeve are both located on the same plane. The outer shell and the core sleeve are sealed and fixed by welding the inner end faces. The cross-section of the tube cap is U-shaped, and the open end of the tube cap is welded to the inner end faces of the outer shell and the core sleeve.

[0012] This utility model also provides another type of socket-pressed double-layer pipe joint, including a main body section. The main body section is provided with at least two communicating connectors. Each connector includes an inner end and an outer end. The inner end is fixedly connected to the main body section, and the outer end is provided with a socket-pressed ring groove formed by a shell and a core sleeve. A special-shaped sealing ring is provided in the socket-pressed ring groove. The special-shaped sealing ring includes a sealing ring body and a radial flange integrally formed at the end of the sealing ring body. The sealing ring body is fixedly sleeved on the core sleeve, and the radial flange is located at the bottom of the socket-pressed ring groove. The shell and the sealing ring body form a socket gap with the radial flange as the pipe end face sealing structure.

[0013] The outer shell and the core sleeve are welded and fixed together, and the inner end of the connector is welded to the main body section.

[0014] The inner end face of the outer shell and the inner end face of the core sleeve are both located on the same plane. The outer shell and the core sleeve are sealed and fixed by welding the inner end faces. The inner end faces of the outer shell and the core sleeve are welded to the main body section.

[0015] Preferably, the bottom cross-section of the socket crimping ring groove is a conical structure, and the radial flange has a conical portion that matches the shape of the conical structure.

[0016] Preferably, the outer end face of the core sleeve and the outer end face of the outer shell are located on the same plane, or the outer end face of the core sleeve extends out of the outer shell.

[0017] Preferably, the wall thickness of the core sleeve is greater than or equal to the wall thickness of the outer shell.

[0018] On the other hand, this utility model provides a pipe connection structure, including a pipe and a socket-pressed double-layer pipe joint. The socket-pressed double-layer pipe joint includes a connector, which includes an outer end and an inner end. The outer end is provided with a socket-pressed ring groove formed by a shell and a core sleeve. A special-shaped sealing ring is provided in the socket-pressed ring groove. The special-shaped sealing ring includes a sealing ring body and a radial flange integrally formed at the end of the sealing ring body. The sealing ring body is fixedly sleeved on the core sleeve. The radial flange is located at the bottom of the socket-pressed ring groove. A socket gap is formed between the sealing ring body and the shell. The end of the pipe is inserted into the socket gap and abuts against the radial flange. The pipe and the socket-pressed double-layer pipe joint are sealed and fixed by a pressing tool.

[0019] When the pipe and the socket-type double-layer pipe joint are sealed and fixed by a crimping tool, the end face of the sealing ring body away from the radial flange corresponds to the cavity range of the crimping tool.

[0020] The socket-type double-layer pipe joint also includes a pipe cap. The outer shell and the core sleeve are welded and fixed together, and the pipe cap is welded to the inner end of the connector.

[0021] The inner end face of the outer shell and the inner end face of the core sleeve are both located on the same plane. The outer shell and the core sleeve are sealed and fixed by welding the inner end faces. The cross-section of the tube cap is U-shaped, and the open end of the tube cap is welded to the inner end faces of the outer shell and the core sleeve.

[0022] The socket-type double-layer pipe joint also includes a main body section, and at least two connectors are disposed on the main body section in a communicating manner. The connectors are fixedly connected to the main body section through their inner ends.

[0023] Preferably, the inner end face of the outer shell and the inner end face of the core sleeve are both located on the same plane, and the outer shell and the core sleeve are sealed and fixed by welding the inner end faces. The end of the main body segment is welded to the inner end faces of the outer shell and the core sleeve.

[0024] Preferably, an anaerobic adhesive layer is provided between the pipe and the outer shell.

[0025] Preferably, the bottom cross-section of the socket crimping ring groove is a conical structure, and the radial flange has a conical portion that matches the shape of the conical structure.

[0026] Preferably, the outer end face of the core sleeve and the outer end face of the outer shell are located on the same plane, or the outer end face of the core sleeve extends out of the outer shell.

[0027] Preferably, the wall thickness of the core sleeve is greater than or equal to the wall thickness of the outer shell.

[0028] The advantages of using this utility model are:

[0029] 1. In this utility model, firstly, a structure consisting of a shell and a core sleeve forming a socket crimping groove is adopted, which provides space for the installation and positioning of the irregular sealing ring, and also provides a structural basis for the insertion and crimping of the pipe, thereby improving the stability and reliability of the connection between the pipe joint and the pipe, enhancing the pressure-bearing capacity and pull-out resistance of the pipeline, and ensuring the firmness of the connection.

[0030] Secondly, by setting a special-shaped sealing ring containing a sealing ring body and a radial flange in the socket crimping ring groove, the special-shaped sealing ring is fixedly sleeved on the core sleeve, and the radial flange is located at the bottom of the socket crimping ring groove, a socket gap is formed between the outer shell and the sealing ring body with the radial flange as the pipe end face sealing structure. When the pipe is inserted into the socket crimping ring groove and abuts against the radial flange, the pipe end face and the radial flange form an end face sealing structure. The inner surface of the pipe and the outer surface of the sealing ring body are closely fitted to form a circumferential surface sealing structure. The double sealing structure significantly improves the structural sealing performance.

[0031] Third, the shaped sealing ring and its radial flange structure expand the applicable pipe diameter range. When positive pressure inside the pipe acts on the shaped sealing ring, the pressure causes the shaped sealing ring to fit more tightly with the core sleeve, pipe material, and outer shell contact surfaces, achieving a self-tightening seal. In addition, the shaped sealing ring and radial flange reduce the dependence on anaerobic adhesive. Even if anaerobic adhesive is filled in the socket crimping ring groove, the anaerobic adhesive will not overflow into the pipe. This significantly improves sealing reliability and reduces maintenance costs while avoiding the risk of pipe blockage.

[0032] In summary, compared with existing crimping, ring crimping, and socket crimping structures, the double-layer crimping structure composed of the outer shell and core sleeve of this utility model, as well as the design of the irregular sealing ring and its radial flange working together for sealing, expands the applicable pipe diameter range. While reducing the dependence on anaerobic adhesive, it effectively solves the problems of sealing ring extrusion and sealing failure, and has higher tensile strength and pressure bearing capacity, thus improving the safety, stability, and reliability of the pipeline system.

[0033] 2. In this utility model, the inner end face of the outer shell and the inner end face of the core sleeve are both located on the same plane, and the outer shell and the core sleeve are sealed and fixed by welding the inner end faces. The open end of the pipe cap or the end of the main body section is welded to the inner end faces of the outer shell and the core sleeve. The pipe cap or the main body section and the connector form an integral structure at the inner end face position, which enhances the sealing performance of the pipe socket crimping double-layer pipe joint and the structural strength of the inner end of the connector.

[0034] 3. In this utility model, by having the end face of the sealing ring body away from the radial flange correspond to the cavity range of the crimping tool, the irregular sealing ring cannot be squeezed out of the socket crimping ring groove under pressure, thus avoiding the sealing ring material from falling into the pipe due to circumferential deformation during crimping, preventing the possibility of sealing failure, and improving the reliability of the pipe connection structure.

[0035] 4. In this utility model, the anaerobic adhesive layer set between the pipe and the outer shell ensures that when the pipe end is inserted, the anaerobic adhesive only adheres to the socket gap formed between the outer surface of the pipe and the inner surface of the outer shell. Furthermore, the irregular sealing ring and its radial flange structure effectively prevent the anaerobic adhesive from overflowing into the pipe. At the same time, because the anaerobic adhesive is isolated from the oxygen environment by the circumferential pressing of the pressing tool within the narrow gap, the anaerobic adhesive can quickly solidify to form a secondary seal, significantly enhancing the sealing performance and pull-out resistance.

[0036] 5. In this utility model, the sealing effect is improved by the bottom cross-section of the socket pressing ring groove being a conical structure and the radial flange having a conical part that matches the shape of the conical structure.

[0037] 6. In this utility model, by having the end face of the core sleeve and the end face of the outer shell on the same plane, or by having the end of the core sleeve extend out of the outer shell, the collapse of the end of the core sleeve after crimping is avoided, which affects the sealing effect and improves the sealing reliability of the pipe connection structure.

[0038] 7. In this utility model, by ensuring that the wall thickness of the core sleeve is greater than or equal to the wall thickness of the outer shell, the core sleeve has sufficient strength, preventing the problem of pipe wall collapse and sealing failure during crimping, and further improving the sealing reliability. Attached Figure Description

[0039] Figure 1 This is a schematic diagram showing the connection between the socket-type double-layer pipe joint and the pipe cap in this utility model;

[0040] Figure 2 This is a schematic diagram of the irregular-shaped sealing ring in this utility model;

[0041] Figure 3 This is a schematic diagram showing the connection between the socket-type double-layer pipe joint and the main body section in this utility model;

[0042] Figure 4 This is an exploded view of the pipe connection structure in this utility model;

[0043] Figure 5 This is a schematic diagram of the structure of the pipe connection structure before it is fixed in this utility model;

[0044] Figure 6 This is a schematic diagram of the structure of the pipe connection structure in this utility model, where the pressure ring is two-layered after fixing.

[0045] Figure 7 This is a schematic diagram of the structure of the pipe connection structure in this utility model, where the pressure ring has three rings after fixing.

[0046] Figure 8 This is a schematic diagram of a structure in the prior art that uses a crimping tool to seal and fix pipe fittings and pipes.

[0047] The numbers in the diagram are: 1. Outer shell, 2. Core sleeve, 3. Connector, 4. Shaped sealing ring, 40. Radial flange, 41. Sealing ring body, 5. Pipe, 6. Anaerobic adhesive layer, 7. Crimping tool, 71. Cavity, 72. Limiting step, 73. Pressure ring, 8. Inner end face, 9. Socket crimping ring groove, 10. Main body section, 11. Pipe cap. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. For ease of description, the description of the relative positional relationships of each component is based on the layout of the accompanying drawings, such as the positional relationships of front, back, top, bottom, left, and right, which are determined according to the layout direction of the accompanying drawings.

[0049] Example 1

[0050] In this embodiment, a socket-type double-layer pipe joint is provided, such as... Figure 1-2 As shown, it includes a connector 3 and a cap 11. The connector 3 includes an inner end and an outer end. The inner end is fixedly connected to the cap 11, and the outer end is provided with a socket crimping ring groove 9 formed by the outer shell 1 and the core sleeve 2. The outer shell 1 and the core sleeve 2 form a double-layer crimping structure at the outer end. A special-shaped sealing ring 4 is provided in the socket crimping ring groove 9, which is combined with... Figure 2 To understand this from the enlarged partial schematic diagram, the irregular sealing ring 4 includes a sealing ring body 41 and a radial flange 40 integrally formed at the end of the sealing ring body 41. The sealing ring body 41 is fixedly sleeved on the core sleeve 2. The radial flange 40 is located at the bottom of the socket crimping ring groove 9. The end face of the sealing ring body 41 away from the radial flange 40 is also located in the socket crimping ring groove 9. The outer shell 1 and the sealing ring body 41 form a socket gap with the radial flange 40 as the pipe end face sealing structure.

[0051] For easy and quick installation, the irregularly shaped sealing ring 4 is preferably made of self-lubricating silicone rubber, EPDM rubber, mild steel or copper, etc. For the gas field, the sealing ring is preferably made of self-lubricating fluororubber or nitrile rubber.

[0052] When the pipe is inserted into the socket for crimping, the pipe end face will press against the radial flange 40, thus forming an end face sealing structure; the inner surface of the pipe will be tightly fitted with the outer surface of the shaped sealing ring 4, thus forming a circumferential sealing structure. When positive pressure occurs inside the pipe, that is, when the pressure generated by the fluid flow acts on the shaped sealing ring 4 radially outward along the pipe, this positive pressure will squeeze the shaped sealing ring 4. Under positive pressure, due to its own structure and installation position, the shaped sealing ring 4 will be squeezed tighter and tighter in the socket crimping ring groove 9, and will fit more tightly with the contact surface of the core sleeve 2, the outer shell 1 and the inserted pipe, thus achieving a better sealing effect.

[0053] Furthermore, the outer shell 1 and the core sleeve 2 are welded together, and the tube cap 11 is welded to the inner end of the connector 3. Specifically, as shown... Figure 1 As shown, the inner end face 8 of the outer shell 1 and the inner end face 8 of the core sleeve 2 are both located on the same plane. The outer shell 1 and the core sleeve 2 are sealed and fixed by welding through the inner end face 8. The cross-section of the pipe cap 11 is U-shaped, and the open end of the pipe cap 11 is welded to the inner end face 8 of the outer shell 1 and the core sleeve 2. Thus, the connector 3 and the pipe cap 11 form an integrated structure by using a circumferential full welding seal at the inner end face 8, which enhances the sealing performance of the pipe socket crimping double-layer pipe joint and the structural strength of the inner end of the connector 3.

[0054] Furthermore, the bottom section of the socket crimping ring groove 9 is a conical structure, and the radial flange 40 has a conical part that matches the shape of the conical structure to improve the sealing effect.

[0055] The outer end face of the core sleeve 2 is on the same plane as the outer end face of the outer shell 1, or the outer end face of the core sleeve 2 extends beyond the outer end face of the outer shell 1, so as to avoid the collapse of the end of the core sleeve 2 after pressing, which would affect the sealing effect.

[0056] Provided that the core sleeve 2 and the outer shell 1 are made of the same material, the wall thickness of the core sleeve 2 is greater than or equal to the wall thickness of the outer shell 1 to ensure that the core sleeve 2 has sufficient strength and to prevent the pipe wall from collapsing during crimping, which would lead to sealing failure.

[0057] Example 2

[0058] This embodiment provides another type of socket-press-fit double-layer pipe joint, such as... Figure 3 As shown, it includes a main body segment 10, which has at least two communicating connectors 3. When the main body segment 10 has two connectors 3, it will form as shown in the figure. Figure 3 , Figure 6-7The pipe joint shown in the diagram, when the main body section 10 has three connectors 3, will form a tee pipe joint; when the main body section 10 has four connectors 3, it will form a four-way pipe joint. This can be understood in conjunction with the patent document with publication number CN102563243A, and will not be elaborated further here. Of course, the main body section 10 can also be designed as a variable diameter pipe structure.

[0059] The connector 3 includes an inner end and an outer end. The inner end is fixedly connected to the main body section 10, and the outer end is provided with a socket crimping ring groove 9 formed by the outer shell 1 and the core sleeve 2. The outer shell 1 and the core sleeve 2 form a double-layer crimping structure at the outer end. A shaped sealing ring 4 is provided inside the socket crimping ring groove 9, which, in conjunction with… Figure 2 To understand this from the enlarged partial schematic diagram, the irregular sealing ring 4 includes a sealing ring body 41 and a radial flange 40 integrally formed at the end of the sealing ring body 41. The sealing ring body 41 is fixedly sleeved on the core sleeve 2. The radial flange 40 is located at the bottom of the socket crimping ring groove 9. The end face of the sealing ring body 41 away from the radial flange 40 is also located in the socket crimping ring groove 9. The outer shell 1 and the sealing ring body 41 form a socket gap with the radial flange 40 as the pipe end face sealing structure.

[0060] For easy and quick installation, the irregularly shaped sealing ring 4 is preferably made of self-lubricating silicone rubber, EPDM rubber, mild steel or copper, etc. For the gas field, the sealing ring is preferably made of self-lubricating fluororubber or nitrile rubber.

[0061] When the pipe is inserted into the socket for crimping, the pipe end face will press against the radial flange 40, thus forming an end face sealing structure; the inner surface of the pipe will be tightly fitted with the outer surface of the shaped sealing ring 4, thus forming a circumferential sealing structure. When positive pressure occurs inside the pipe, that is, when the pressure generated by the fluid flow acts on the shaped sealing ring 4 radially outward along the pipe, this positive pressure will squeeze the shaped sealing ring 4. Under positive pressure, due to its own structure and installation position, the shaped sealing ring 4 will be squeezed tighter and tighter in the socket crimping ring groove 9, and will fit more tightly with the contact surface of the core sleeve 2, the outer shell 1 and the inserted pipe, thus achieving a better sealing effect.

[0062] Furthermore, the outer shell 1 and the core sleeve 2 are welded and fixed together, and the inner end of the connector 3 is welded to the main body section 10. Specifically, as shown... Figure 3 As shown, the inner end face 8 of the outer shell 1 and the inner end face 8 of the core sleeve 2 are both located on the same plane. The outer shell 1 and the core sleeve 2 are sealed and fixed by welding through the inner end face 8. The inner end faces of the outer shell 1 and the core sleeve 2 are welded to the main body section 10. Thus, the connector 3 and the main body section 10 form an integrated structure by using a circumferential full welding seal at the inner end face 8, which enhances the sealing performance of the pipe socket crimping double-layer pipe joint and the structural strength of the inner end of the connector 3.

[0063] Furthermore, the bottom section of the socket crimping ring groove 9 is a conical structure, and the radial flange 40 has a conical part that matches the shape of the conical structure to improve the sealing effect.

[0064] The outer end face of the core sleeve 2 is on the same plane as the outer end face of the outer shell 1, or the outer end face of the core sleeve 2 extends beyond the outer end face of the outer shell 1, so as to avoid the collapse of the end of the core sleeve 2 after pressing, which would affect the sealing effect.

[0065] Provided that the core sleeve 2 and the outer shell 1 are made of the same material, the wall thickness of the core sleeve 2 is greater than or equal to the wall thickness of the outer shell 1 to ensure that the core sleeve 2 has sufficient strength and to prevent the pipe wall from collapsing during crimping, which would lead to sealing failure.

[0066] Example 3

[0067] This embodiment provides a pipe connection structure, such as Figure 4-5 As shown, the device includes pipe 5 and a socket-pressed double-layer pipe fitting. The socket-pressed double-layer pipe fitting includes a connector 3, which has an outer end and an inner end. The inner end is sealed and fixed by a shell 1 and a core sleeve 2. The outer end is provided with a socket-pressing annular groove 9 formed by the shell 1 and the core sleeve 2. The shell 1 and the core sleeve 2 form a double-layer pressing structure at the outer end.

[0068] A special-shaped sealing ring 4 is provided in the socket crimping ring groove 9, which is combined with Figure 2 and Figure 4 To understand this from a magnified partial schematic diagram, the irregular sealing ring 4 includes a sealing ring body 41 and a radial flange 40 integrally formed at the end of the sealing ring body 41. The sealing ring body 41 is fixedly sleeved on the core sleeve 2. The radial flange 40 is located at the bottom of the socket crimping ring groove 9. The end face of the sealing ring body 41 away from the radial flange 40 is also located in the socket crimping ring groove 9. A socket gap is formed between the sealing ring body 41 and the outer shell 1. The end of the pipe 5 is inserted into the socket gap and abuts against the radial flange 40. The pipe 5 and the socket crimping double-layer pipe joint are sealed and fixed by the crimping tool 7.

[0069] For easy and quick installation, the irregularly shaped sealing ring 4 is preferably made of self-lubricating silicone rubber, EPDM rubber, mild steel or copper, etc. For the gas field, the sealing ring is preferably made of self-lubricating fluororubber or nitrile rubber.

[0070] When the pipe is inserted into the socket for crimping, the pipe end face will press against the radial flange 40, thus forming an end face sealing structure; the inner surface of the pipe will be tightly fitted with the outer surface of the shaped sealing ring 4, thus forming a circumferential sealing structure. When positive pressure occurs inside the pipe, that is, when the pressure generated by the fluid flow acts on the shaped sealing ring 4 radially outward along the pipe, this positive pressure will squeeze the shaped sealing ring 4. Under positive pressure, due to its own structure and installation position, the shaped sealing ring 4 will be squeezed tighter and tighter in the socket crimping ring groove 9, and will fit more tightly with the contact surface of the core sleeve 2, the outer shell 1 and the inserted pipe, thus achieving a better sealing effect.

[0071] When positive pressure occurs inside the pipe connection structure formed by the connection of pipe 5 and the socket-pressed double-layer pipe fitting, i.e., when the pressure generated by fluid flow acts radially outward along the pipe connection structure on the shaped sealing ring 4, this positive pressure will squeeze the shaped sealing ring 4. After being subjected to positive pressure, due to its own structure and installation position, the shaped sealing ring 4 is squeezed tighter and tighter in the socket-pressing ring groove 9, and fits more closely with the contact surfaces of the core sleeve 2, the outer shell 1 and the inserted pipe 5, thus achieving a better sealing effect. At this time, even if the outer surface of the shaped sealing ring 4 is filled with a sealing material such as anaerobic adhesive between the outer surface of the sealing ring 4 and the inner surface of the outer shell 1, the structural design of the shaped sealing ring 4 and its radial flange 40 can effectively prevent the sealing material from overflowing into the pipe connection structure during the process of the pressing tool 7 pressing inward along the circumference.

[0072] When pipe 5 and socket-type double-layer pipe fitting are sealed and fixed together by crimping tool 7, such as Figure 5 As shown, the end face of the sealing ring body 41 away from the radial flange 40 corresponds to the cavity 71 of the crimping tool 7. Through the structure of the irregularly shaped sealing ring 4 and its radial flange 40, and the design of the pressing position of the end face of the sealing ring body 41 away from the radial flange 40 corresponding to the cavity 71 of the crimping tool 7, the irregularly shaped sealing ring 4 cannot be squeezed out of the socket crimping groove 9 under pressure, preventing the possibility of seal failure. Preferably, when the pipe 5 and the socket crimping double-layer pipe joint are sealed and fixed using the crimping tool 7, the... Figure 5 Taking the direction shown as an example, the end face of the sealing ring body 41 that is away from the radial flange 40 is close to the right-hand groove of the crimping tool 7, thereby preventing the irregular sealing ring material from falling into the pipe due to circumferential deformation during crimping.

[0073] Furthermore, such as Figure 4-5 As shown, an anaerobic adhesive layer 6 is provided between the pipe 5 and the outer shell 1. That is, the axial length of the anaerobic adhesive layer 6 is L, and the axial distance formed between the radial flange 40 and the outer end face of the outer shell 1 is L1, and L = L1. Therefore, when the end of the pipe 5 is inserted into the socket gap and abuts against the radial flange 40, this precise length matching design eliminates glue waste and saves material resources.

[0074] After the end of the pipe 5 is inserted into the socket gap and crimped, the anaerobic adhesive layer 6 is only attached to the narrow gap formed between the outer surface of the pipe 5 and the inner surface of the outer shell 1 in the socket crimping ring groove 9. In addition, the structural design of the irregular sealing ring 4 and its radial flange 40, through the circumferential crimping of the crimping tool 7, effectively isolates the oxygen environment, and the anaerobic adhesive solidifies quickly. After solidification, the anaerobic adhesive has good adhesion and torque resistance, thus playing the role of secondary sealing and enhancing pull-out resistance.

[0075] Furthermore, the bottom section of the socket crimping ring groove 9 is a conical structure, and the radial flange 40 has a conical part that matches the shape of the conical structure to improve the sealing effect.

[0076] The outer end face of the core sleeve 2 is on the same plane as the outer end face of the outer shell 1, or the outer end face of the core sleeve 2 extends beyond the outer end face of the outer shell 1, so as to avoid the collapse of the end of the core sleeve 2 after pressing, which would affect the sealing effect.

[0077] Provided that the core sleeve 2 and the outer shell 1 are made of the same material, the wall thickness of the core sleeve 2 is greater than or equal to the wall thickness of the outer shell 1 to ensure that the core sleeve 2 has sufficient strength and to prevent the pipe wall from collapsing during crimping, which would lead to sealing failure.

[0078] In this embodiment, when using the crimping tool 7 to crimp and seal the pipe 5 and the socket crimp-type double-layer pipe joint, the following steps are included:

[0079] (1) Select pipe material 5 with no burrs on the cross section, and whose cutting angle and non-roundness meet the national standards. If pipe material 5 does not meet the requirements, it should be treated (refer to GB / T12771).

[0080] (2) Coat the outer surface of the selected pipe 5 with an anaerobic adhesive layer 6, such that the coating length, i.e. the axial length L of the anaerobic adhesive layer 6, is equal to the axial distance L1 formed between the radial flange 40 and the outer end face of the outer shell 1. This step can be omitted when the pressure rating of the connected pipeline system is ≤1.6MPa.

[0081] (3) Insert the end of the pipe 5 into the socket gap, and the end of the pipe 5 abuts against the radial flange 40. To visually feel whether the end of the pipe 5 is fully inserted into the socket gap, the pipe 5 can be marked according to the axial distance L1 formed between the radial flange 40 and the outer end face of the outer shell 1 before insertion.

[0082] (4) After the end of the pipe 5 is fully inserted into the socket gap, the socket-pressed double-layer pipe joint can be rotated appropriately to make the anaerobic adhesive layer 6 more evenly distributed. If the on-site construction conditions do not allow it, it can be left unrotated.

[0083] (5) Finally, use the crimping tool 7 to crimp the pipe 5 and the socket crimping double-layer pipe joint. When crimping, pay attention to placing the end face of the outer shell 1 on the limiting step 72 of the crimping tool 7 before applying pressure, and form a shape as shown in the figure. Figure 5-6 The crimping effect. Specifically, before the pipe connection structure is crimped, the limiting step 72 of the crimping tool 7 is positioned by the end face of the outer shell 1. After shrink crimping, the pipe connection structure is formed as follows: Figure 5 The two pressure rings 73 shown or as Figure 6 The circumferential sealing structure of the three pressure rings 73 shown is preferably used in the form of two pressure rings when connecting pipes with a diameter of DN200 or less, and in the form of three or more pressure rings when connecting pipes with a diameter greater than DN200.

[0084] To ensure effective solidification of the anaerobic adhesive layer 6, a raised ring is added between the cavities 71 of the crimping tool 7. This raised ring can be circumferential or spiral. During pipe crimping, this raised ring reduces the gap between the outer shell 1 and the pipe 5, preventing oxygen from entering the gap. Simultaneously, it ensures that the irregularly shaped sealing ring 4 is also uniformly compressed and filled, allowing the outer shell 1, anaerobic adhesive layer 6, pipe 5, sealing ring 4, and core sleeve 2 to form a... Figure 5-6 The dense, monolithic tubular connection structure shown.

[0085] Example 4

[0086] Based on Example 3, the structure of the socket-type double-layer pipe joint has been optimized in this example.

[0087] like Figure 1 As shown, the socket-type double-layer pipe joint also includes a pipe cap 11. The outer shell 1 and the core sleeve 2 are welded and fixed together, and the pipe cap 11 is welded to the inner end of the connector 3.

[0088] Specifically, the inner end face 8 of the outer shell 1 and the inner end face 8 of the core sleeve 2 are both located on the same plane, and the outer shell 1 and the core sleeve 2 are sealed and fixed by welding through the inner end face 8. The cross-section of the pipe cap 11 is U-shaped, and the open end of the pipe cap 11 is welded to the inner end face 8 of the outer shell 1 and the core sleeve 2. Thus, the connector 3 and the pipe cap 11 form an integrated structure by using a circumferential full welding seal at the inner end face 8, thereby enhancing the sealing performance of the double-layer pipe joint and the structural strength of the inner end of the connector 3.

[0089] Example 5

[0090] Based on Example 3, this example further optimizes the structure of the socket-type double-layer pipe joint.

[0091] like Figure 3As shown, the socket-type double-layer pipe fitting also includes a main body section 10, and at least two connectors 3 are provided on the main body section 10 in a communicating manner. The connectors 3 are fixedly connected to the main body section 10 through their inner ends. When the main body section 10 is provided with two connectors 3, it will form as shown in the figure. Figure 3 , Figure 6-7 The pipe joint shown in the diagram, when the main body section 10 has three connectors 3, will form a tee pipe joint; when the main body section 10 has four connectors 3, it will form a four-way pipe joint. This can be understood in conjunction with the patent document with publication number CN102563243A, and will not be elaborated further here. Of course, the main body section 10 can also be designed as a variable diameter pipe structure.

[0092] The outer shell 1 and the core sleeve 2 are welded together. Specifically, the inner end face 8 of the outer shell 1 and the inner end face 8 of the core sleeve 2 are both located on the same plane. The outer shell 1 and the core sleeve 2 are sealed and fixed by welding through the inner end face 8. The inner end faces 8 of the outer shell 1 and the core sleeve 2 are welded to the main body section 10. Thus, the connector 3 and the main body section 10 form an integrated structure by using a circumferential full welding seal at the inner end face 8, thereby enhancing the sealing performance of the pipe socket crimping double-layer pipe joint and the structural strength of the inner end of the connector 3.

[0093] The above description is only a specific embodiment of the present utility model. Any feature disclosed in this specification may be replaced by other equivalent or similar features unless otherwise specified. All features or steps in all methods or processes disclosed may be combined in any way except for mutually exclusive features and / or steps.

Claims

1. A socket-type double-layer pipe fitting, characterized in that: The device includes a connector (3) and a cap (11). The connector (3) includes an inner end and an outer end. The inner end is fixedly connected to the cap (11). The outer end is provided with a socket crimping ring groove (9) formed by the outer shell (1) and the core sleeve (2). The socket crimping ring groove (9) is provided with a special-shaped sealing ring (4). The special-shaped sealing ring (4) includes a sealing ring body (41) and a radial flange (40) integrally formed at the end of the sealing ring body (41). The sealing ring body (41) is fixedly sleeved on the core sleeve (2). The radial flange (40) is located at the bottom of the socket crimping ring groove (9). The outer shell (1) and the sealing ring body (41) form a socket gap with the radial flange (40) as the sealing structure of the pipe end face.

2. The socket-type double-layer pipe joint according to claim 1, characterized in that: The outer shell (1) and the core sleeve (2) are welded and fixed together, and the tube cap (11) is welded to the inner end of the connector (3).

3. A socket-type double-layer pipe joint according to claim 2, characterized in that: The inner end face of the outer shell (1) and the inner end face of the core sleeve (2) are both located on the same plane. The outer shell (1) and the core sleeve (2) are sealed and fixed by welding the inner end faces. The cross-section of the tube cap (11) is U-shaped, and the open end of the tube cap (11) is welded to the inner end faces of the outer shell (1) and the core sleeve (2).

4. A socket-type double-layer pipe joint, comprising a main body section (10), characterized in that: The main body section (10) is provided with at least two communicating connectors (3). The connector (3) includes an inner end and an outer end. The inner end is fixedly connected to the main body section (10). The outer end is provided with a socket crimping ring groove (9) formed by the outer shell (1) and the core sleeve (2). The socket crimping ring groove (9) is provided with a special-shaped sealing ring (4). The special-shaped sealing ring (4) includes a sealing ring body (41) and a radial flange (40) integrally formed at the end of the sealing ring body (41). The sealing ring body (41) is fixedly sleeved on the core sleeve (2). The radial flange (40) is located at the bottom of the socket crimping ring groove (9). The outer shell (1) and the sealing ring body (41) form a socket gap with the radial flange (40) as the pipe end face sealing structure.

5. A socket-type double-layer pipe joint according to claim 4, characterized in that: The outer shell (1) and the core sleeve (2) are welded and fixed together, and the inner end of the connector (3) is welded to the main body section (10).

6. A socket-type double-layer pipe joint according to claim 5, characterized in that: The inner end face of the outer shell (1) and the inner end face of the core sleeve (2) are both located on the same plane. The outer shell (1) and the core sleeve (2) are sealed and fixed by welding the inner end faces. The inner end faces of the outer shell (1) and the core sleeve (2) are welded to the main body section (10).

7. A socket-type double-layer pipe fitting according to any one of claims 1-6, characterized in that: The bottom section of the socket crimping ring groove (9) is a conical structure, and the radial flange (40) has a conical part that matches the shape of the conical structure.

8. A socket-type double-layer pipe fitting according to any one of claims 1-6, characterized in that: The outer end face of the core sleeve (2) is on the same plane as the outer end face of the outer shell (1), or the outer end face of the core sleeve (2) extends out of the outer shell (1).

9. A socket-type double-layer pipe fitting according to any one of claims 1-6, characterized in that: The wall thickness of the core sleeve (2) is greater than or equal to the wall thickness of the outer shell (1).

10. A pipe connection structure, characterized in that: The device includes a pipe (5) and a socket-pressed double-layer pipe fitting. The socket-pressed double-layer pipe fitting includes a connector (3). The connector (3) includes an outer end and an inner end. The outer end is provided with a socket-pressed ring groove (9) formed by a shell (1) and a core sleeve (2). The socket-pressed ring groove (9) is provided with a shaped sealing ring (4). The shaped sealing ring (4) includes a sealing ring body (41) and a radial flange (40) integrally formed at the end of the sealing ring body (41). The sealing ring body (41) is fixedly sleeved on the core sleeve (2). The radial flange (40) is located at the bottom of the socket-pressed ring groove (9). A socket gap is formed between the sealing ring body (41) and the shell (1). The end of the pipe (5) is inserted into the socket gap and abuts against the radial flange (40). The pipe (5) and the socket-pressed double-layer pipe fitting are sealed and fixed by a pressing tool (7).

11. A pipe connection structure according to claim 10, characterized in that: When the pipe (5) and the socket-type double-layer pipe joint are sealed and fixed by the crimping tool (7), the end face of the sealing ring body (41) away from the radial flange (40) is within the cavity (71) of the crimping tool (7).

12. A pipe connection structure according to claim 11, characterized in that: The socket-type double-layer pipe joint also includes a pipe cap (11), the outer shell (1) and the core sleeve (2) are welded and fixed together, and the pipe cap (11) is welded to the inner end of the connector (3).

13. A pipe connection structure according to claim 12, characterized in that: The inner end face of the outer shell (1) and the inner end face of the core sleeve (2) are both located on the same plane. The outer shell (1) and the core sleeve (2) are sealed and fixed by welding the inner end faces. The cross-section of the tube cap (11) is U-shaped, and the open end of the tube cap (11) is welded to the inner end faces of the outer shell (1) and the core sleeve (2).

14. A pipe connection structure according to claim 11, characterized in that: The socket-type double-layer pipe joint also includes a main body section (10), and at least two connectors (3) are provided on the main body section (10) in a communicating manner. The connectors (3) are fixedly connected to the main body section (10) through their inner ends.

15. A pipe connection structure according to claim 14, characterized in that: The inner end face of the outer shell (1) and the inner end face of the core sleeve (2) are both located on the same plane. The outer shell (1) and the core sleeve (2) are sealed and fixed by welding the inner end faces. The inner end faces of the outer shell (1) and the core sleeve (2) are welded to the main body section (10).

16. A pipe connection structure according to any one of claims 10-15, characterized in that: An anaerobic adhesive layer (6) is provided between the pipe (5) and the outer shell (1).

17. A pipe connection structure according to any one of claims 10-15, characterized in that: The bottom section of the socket crimping ring groove (9) is a conical structure, and the radial flange (40) has a conical part that matches the shape of the conical structure.

18. A pipe connection structure according to any one of claims 10-15, characterized in that: The outer end face of the core sleeve (2) is on the same plane as the outer end face of the outer shell (1), or the outer end face of the core sleeve (2) extends out of the outer shell (1).

19. A pipe connection structure according to any one of claims 10-15, characterized in that: The wall thickness of the core sleeve (2) is greater than or equal to the wall thickness of the outer shell (1).

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