A sealing structure of a ductile cast iron pipe

Abstract

The application discloses a sealing structure of nodular cast iron pipes and relates to the technical field of pipeline connection. The sealing structure comprises a sealing assembly arranged between two nodular cast iron pipes and a connecting assembly for connecting the two nodular cast iron pipes. The sealing assembly comprises a first elastic pad arranged in the interior of the nodular cast iron pipe, and a hollow support is fixedly connected to the interior of the first elastic pad. The gap between the first elastic pad and the hollow support is filled with a first solidifying agent. An annular gasket is arranged between the two nodular cast iron pipes, and the outer wall of the annular gasket is provided with an annular piece. The connecting assembly comprises a second fixing piece fixedly installed on the outer wall of the nodular cast iron pipe, and the inner wall of the second fixing piece is fixedly connected with a second extruding piece. The sealing structure of the nodular cast iron pipe can realize reliable sealing effect and ensure installation efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of pipeline connection, in particular to a sealing structure of a nodular cast iron pipe. BACKGROUND

[0002] The nodular cast iron pipe is superior in performance to the traditional cast iron pipe and is a main pipeline material for water supply and gas transmission at present. Since the conveying distance is generally long, the interface structure between the nodular cast iron pipes becomes a key factor for installation connection and sealing.

[0003] Patent No. CN117028691A discloses an interface sealing structure and a connecting method of a T-shaped nodular cast iron pipe fitting. An active ring is detachably arranged on the outer sidewall of a spigot. The active ring is divided into a diagonal segment, a vertical segment and a horizontal segment in the axial direction. A hanging piece is arranged on the horizontal segment and is hung on the outer sidewall of a socket so that the active ring and the socket are arranged in concentric circles. A plurality of active compression pieces are arranged on the diagonal segment in the circumferential direction. The active compression pieces press against the outer sidewall of the spigot. The radial positions of the active compression pieces on the diagonal segment are different, so that the turning angle of the spigot relative to the socket is adjusted. When the pipeline is turned and installed for a long distance, the active deflection angle is easy to operate, labor-saving and relatively more reliable in accuracy. The active ring and the hanging piece are limited to avoid the axial transverse slip of the interface.

[0004] When the pipeline is installed, whether the pipeline has been connected with other fixed structures needs to be considered. When the positions of the two pipelines are fixed, the sealing rubber ring and the active ring in the above structure are not convenient to install when the sealing structure is installed at the positions of the two pipelines, thereby affecting the installation efficiency. Therefore, the sealing structure of the nodular cast iron pipe is invented. SUMMARY

[0005] The application aims to provide a sealing structure of a nodular cast iron pipe to solve the problems in the background art.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme.

[0007] A sealing structure of a nodular cast iron pipe comprises a sealing assembly arranged between two nodular cast iron pipelines and a connecting assembly connecting the two nodular cast iron pipelines.

[0008] The sealing assembly comprises a first sealing inner ring. The inside of the first sealing inner ring is provided with a compression ring. One side of the compression ring is provided with a first secondary gasket. One side of the first secondary gasket is provided with a first ring piece. The inside of the first ring piece is installed with a positioning rod.

[0009] The connecting assembly comprises a first fixing member fixedly installed on the outer wall of the duct, and a first clamping member for limiting the first ring member is fixedly connected inside the first fixing member.

[0010] Based on the same inventive concept, a sealing structure of a ductile cast iron pipe is also provided, which comprises a sealing assembly arranged between two ductile cast iron pipes and a connecting assembly connecting the two ductile cast iron pipes.

[0011] The sealing assembly comprises a first elastic pad arranged inside the ductile cast iron pipe, a hollow support fixedly connected inside the first elastic pad, a first curing agent filled between the first elastic pad and the hollow support, an annular gasket arranged between the two ductile cast iron pipes, and an annular member arranged on the outer wall of the annular gasket.

[0012] The connecting assembly comprises a second fixing member fixedly installed on the outer wall of the ductile cast iron pipe, and a second extruding member fixedly connected to the inner wall of the second fixing member.

[0013] Based on the same inventive concept, a sealing structure of a ductile cast iron pipe is also provided, which comprises a sealing assembly arranged between two ductile cast iron pipes and a connecting assembly connecting the two ductile cast iron pipes.

[0014] The sealing assembly comprises a second elastic pad arranged inside the ductile cast iron pipe, a T-shaped ring member fixedly connected inside the second elastic pad, a limiting ring member arranged on the outer wall of the T-shaped ring member, an elastic ring pad arranged between the limiting ring member and the second elastic pad, and a second curing agent filled between the second elastic pad and the T-shaped ring member.

[0015] The connecting assembly comprises a third fixing member arranged on the outer wall of the ductile cast iron pipe, a third clamping member for clamping the limiting ring member fixedly connected inside the third fixing member, a third extruding ring member slidingly connected to the inner wall of the third fixing member, a third contact ring member arranged between the third extruding ring member and the third clamping member, and a third threaded rod member for extruding the third extruding ring member threadedly connected inside the third fixing member.

[0016] Based on the same inventive concept, a sealing structure of a ductile cast iron pipe is also provided, which comprises a sealing assembly arranged between two ductile cast iron pipes and a connecting assembly connecting the two ductile cast iron pipes.

[0017] The sealing assembly comprises a ring pad member arranged inside the ductile cast iron pipe, a moving ring arranged on the outer wall of the ring pad member, a first gasket arranged on both sides of the moving ring, a second gasket arranged on one end of the ductile cast iron pipe, and a trapezoidal member arranged between the first gasket and the second gasket.

[0018] The connecting assembly comprises a fourth fixing member arranged outside the duct of the ductile cast iron pipe, an inclined ring member arranged inside the fourth fixing member and arranged to contact the trapezoidal member, and a fourth extrusion ring member arranged inside the fourth fixing member and arranged to limit the movement of the ring.

[0019] Based on the same inventive concept, a sealing structure of a ductile cast iron pipe is also provided, which comprises a sealing assembly arranged between two ducts of the ductile cast iron pipe and a connecting assembly connecting the two ducts of the ductile cast iron pipe.

[0020] The sealing assembly comprises a fifth gasket arranged between the two ducts of the ductile cast iron pipe, and a fifth gasket ring arranged on the outer wall of the duct of the ductile cast iron pipe.

[0021] The connecting assembly comprises a fifth sleeve arranged on the outer wall of the duct of the ductile cast iron pipe, a connecting ring fixedly connected to the outer wall of the duct of the ductile cast iron pipe, and a bolt and nut connection between the fifth sleeve and the connecting ring, a sleeve ring arranged inside the fifth sleeve and arranged to extrude the fifth gasket ring, and a fifth threaded rod threadedly connected to the inner wall of the fifth gasket ring and arranged to extrude the sleeve ring.

[0022] Based on the same inventive concept, a sealing structure of a ductile cast iron pipe is also provided, which comprises a sealing assembly arranged between two ducts of the ductile cast iron pipe and a connecting assembly connecting the two ducts of the ductile cast iron pipe.

[0023] The sealing assembly comprises a sixth gasket arranged on the outer wall of the duct of the ductile cast iron pipe, and a sixth gasket ring arranged on one side of the sixth gasket.

[0024] The connecting assembly comprises a sixth sleeve, the inner wall of the sixth sleeve is slidably connected to the outer wall of the duct of the ductile cast iron pipe, a sixth fixed ring fixedly connected to the inner wall of the duct of the ductile cast iron pipe, a sixth threaded rod threadedly connected to the inner part of the sixth fixed ring, a sixth auxiliary sleeve arranged between the sixth fixed ring and the duct of the ductile cast iron pipe, and a sixth extrusion ring arranged on one side of the sixth gasket.

[0025] Based on the same inventive concept, a sealing structure of a ductile cast iron pipe is also provided, which comprises a sealing assembly arranged between two ducts of the ductile cast iron pipe and a connecting assembly connecting the two ducts of the ductile cast iron pipe.

[0026] The sealing assembly comprises a seventh gasket arranged on the outer wall of the duct of the ductile cast iron pipe.

[0027] The connecting assembly comprises a seventh sleeve arranged on the outer wall of the duct of the ductile cast iron pipe, and a seventh extrusion ring fixedly connected to the inner part of the seventh sleeve and arranged to extrude the seventh gasket.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] The sealing structure of the spheroidal graphite cast iron pipe can adapt to the scene of one spheroidal graphite cast iron pipe being fixed and the other being freely installed, and the scene of both spheroidal graphite cast iron pipes being fixed, thereby improving the flexibility and convenience of installation, and providing corresponding sealing structures for one-way and two-way flow of the medium in the spheroidal graphite cast iron pipe, thereby ensuring reliable sealing effect in different flow directions and installation efficiency.

[0030] Meanwhile, the combination of the multi-layer sealing assembly and the filling and curing of the curing agent in the embodiment significantly enhances the sealing performance of the spheroidal graphite cast iron pipe interface, effectively prevents leakage, and designs corresponding sealing structures for different flow characteristics of the medium, thereby ensuring excellent sealing effect for one-way or two-way flowing medium. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a sectional view of the present application.

[0032] Figure 2 is a sectional view of embodiment one of the present application.

[0033] Figure 3 is a sectional view of embodiment two of the present application.

[0034] Figure 4 is a sectional view of embodiment three of the present application.

[0035] Figure 5 is a sectional view of embodiment four of the present application.

[0036] Figure 6 is a sectional view of embodiment five of the present application.

[0037] Figure 7 is a sectional view of embodiment six of the present application.

[0038] Figure 8 is a sectional view of embodiment seven of the present application.

[0039] In the figure:

[0040] spheroidal graphite cast iron pipe; 2, sealing assembly; 3, connecting assembly;

[0041] 201, first sealing inner ring; 202, compression ring; 203, first sub-gasket; 204, first ring; 205, positioning rod; 206, first elastic pad; 207, hollow support; 208, first curing agent; 209, annular gasket; 210, annular ring; 211, second elastic pad; 212, T-shaped ring; 213, limiting ring; 214, elastic ring pad; 215, second curing agent; 216, ring pad; 217, moving ring; 218, first gasket; 219, second gasket; 220, trapezoidal ring; 221, fifth gasket; 222, fifth gasket ring; 223, sixth gasket; 224, sixth gasket ring; 225, seventh gasket;

[0042] 301, first fixing member; 302, first clamping member; 303, second fixing member; 304, second extrusion member; 305, third fixing member; 306, third clamping member; 307, third extrusion ring member; 308, third contact ring member; 309, third threaded rod member; 310, fourth fixing member; 311, fourth extrusion ring member; 312, fifth sleeve; 313, connecting ring; 314, sleeve ring; 315, fifth threaded rod; 316, sixth sleeve; 317, sixth fixing ring; 318, sixth threaded rod; 319, sixth sub-sleeve; 320, sixth extrusion ring; 321, seventh sleeve; 322, seventh extrusion ring; 323, inclined ring member. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0044] Embodiment one

[0045] As shown in Figure 1 and Figure 2 , the present application provides a sealing structure of a ductile cast iron pipe, which comprises a sealing assembly 2 arranged between two ductile cast iron pipes 1 and a connecting assembly 3 connecting the two ductile cast iron pipes 1.

[0046] The sealing assembly 2 comprises a first sealing inner ring 201, the inside of the first sealing inner ring 201 is provided with a compression ring 202, one side of the compression ring 202 is provided with a first sub-gasket 203, one side of the first sub-gasket 203 is provided with a first ring 204, and the inside of the first ring 204 is installed with a positioning rod 205.

[0047] The connecting assembly 3 includes a first fixing member 301, which is fixedly installed on the outer wall of the ductile iron pipe 1. A first clamping member 302 for limiting the first ring member 204 is fixedly connected inside the first fixing member 301.

[0048] like Figure 1 and Figure 2 As shown, during use, the first sealing inner ring 201 is placed inside the ductile iron pipe 1, and then a clamping ring 202 is installed inside the first sealing inner ring 201. The clamping ring 202 is formed by two semi-annular clamping rings (not shown in the figure, this structure is conventional technology in the field and will not be described in detail here) connected to each other. After the two semi-annular clamping rings come into contact with each other, the position between the two semi-annular clamping rings can be fixed by additional bolts and nuts (not shown in the figure). A force is applied to the first sealing inner ring 201 by the clamping ring 202, thereby ensuring that the first sealing inner ring 201, located between the clamping ring 202 and the inner wall of the ductile iron pipe 1, is subjected to the pressure of the clamping ring 202. Then, a first auxiliary washer 203 is installed between the clamping ring 202 and the first sealing inner ring 201. The first auxiliary washer 203 applies a force to the clamping ring 202, thus ensuring the sealing effect between the outer wall of the first sealing inner ring 201 and the ductile iron pipe 1. The outer wall of the clamping ring 202, the portion in contact with the first sealing inner ring 201, is beveled. This beveled design allows the clamping ring 202 to be inserted into the interior of the first sealing inner ring 201, and under the action of the first auxiliary washer 203, the clamping ring 202 maintains pressure on the first sealing inner ring 201. Finally, the connecting assembly 3 restricts the first sealing inner ring 201. The first fixing member 301 is installed. The two first fixing members 301 can be connected by a threaded rod or other means to achieve stability between them. During the connection process, the first fixing member 301 compresses the first sealing inner ring 201 through the first clamping member 302, thereby restricting the position between the first sealing inner ring 201 and the first fixing member 301. The positioning rod 205 installed on the first ring member 204 can restrict the clamping ring 202 and the first secondary washer 203 through the positioning rod 205, thereby achieving a seal between the two ductile iron pipes 1. In the first embodiment, the degree of compression of the clamping ring 202 is adjusted by bolts to adapt to different gaps in ductile iron pipes. The positioning rod 205 passes through each component to ensure the alignment of the seals and avoid installation misalignment. It is suitable for connecting movable ductile iron pipes and fixed ductile iron pipes and has high installation flexibility.

[0049] Example 2

[0050] like Figure 3 As shown, the difference from Embodiment 1 above is that in this specific embodiment:

[0051] The sealing assembly 2 includes a first elastic pad 206, which is disposed inside the ductile iron pipe 1. A hollow support 207 is fixedly connected inside the first elastic pad 206. The gap between the first elastic pad 206 and the hollow support 207 is filled with a first curing agent 208. An annular washer 209 is disposed between the two ductile iron pipes 1. An annular member 210 is disposed on the outer wall of the annular washer 209.

[0052] The connecting component 3 includes a second fastener 303, which is fixedly installed on the outer wall of the ductile iron pipe 1, and a second extrusion member 304 is fixedly connected to the inner wall of the second fastener 303.

[0053] like Figure 3 As shown in the figure, the arrows indicate the flow direction of the medium inside the ductile iron pipe 1. This sealing structure is mainly used on unidirectional flow ductile iron pipes 1. The fit between the first elastic pad 206 and the hollow support 207 is described. Simultaneously, a first curing agent 208 is added to the gap between the first elastic pad 206 and the hollow support 207. The first curing agent 208 is liquid in the sealed state and can cure upon contact with the outside environment. During the installation of the sealing assembly 2, the first elastic pad 206 and the hollow support 207 are placed inside the ductile iron pipe 1 first, and then the first curing agent 208 is added to the gap between the first elastic pad 206 and the hollow support 207 until the first curing agent 208 hardens. After curing, the annular washer 209 is installed, and the two ductile iron pipes 1 are pressed against the annular washer 209. Then, the two ductile iron pipes 1 can be fixed in a straight line by the connecting component 3. The two second fixing parts 303 are connected. The second pressing part 304 on the second fixing part 303 can fix the annular part 210, thereby realizing the installation of the sealing structure. In the second embodiment, the liquid curing agent 208 is filled and cured, perfectly fitting the irregular surface of the inner wall of the ductile iron pipe. The hollow support 207 resists the positive pressure and prevents backflow leakage. The first elastic pad 206 absorbs the fluid impact vibration, prolongs the sealing life, and is suitable for the unidirectional flow of the medium in the ductile iron pipe 1.

[0054] Example 3

[0055] like Figure 4 As shown, the difference from Embodiment 1 above is that in this specific embodiment:

[0056] The sealing assembly 2 includes a second elastic pad 211, which is disposed inside the ductile iron pipe 1. A T-shaped ring 212 is fixedly connected inside the second elastic pad 211. A limiting ring 213 is disposed on the outer wall of the T-shaped ring 212. An elastic ring pad 214 is disposed between the limiting ring 213 and the second elastic pad 211. The gap between the second elastic pad 211 and the T-shaped ring 212 is filled with a second curing agent 215.

[0057] The connecting assembly 3 includes a third fixing member 305, which is disposed on the outer wall of the ductile iron pipe 1. A third clamping member 306 for clamping the limiting ring 213 is fixedly connected inside the third fixing member 305. A third extrusion ring 307 is slidably connected to the inner wall of the third fixing member 305. A third contact ring 308 is provided between the third extrusion ring 307 and the third clamping member 306. A third threaded rod 309 for extruding the third extrusion ring 307 is threadedly connected inside the third fixing member 305.

[0058] like Figure 4 As shown, the sealing structure of the ductile iron pipe disclosed in this embodiment is mainly applied to the ductile iron pipe 1 that can flow in both directions. During installation, the second elastic pad 211 and the T-shaped ring 212 are first placed inside the ductile iron pipe 1. Then, the second curing agent 215 is filled through the gap between the second elastic pad 211 and the T-shaped ring 212 until the second curing agent 215 solidifies. After that, an elastic ring pad 214 is set between the T-shaped ring 212 and the ductile iron pipe 1, and the elastic ring pad 214 is squeezed. Then, the position between the two ductile iron pipes 1 is fixed by the connecting component 3, and the limiting ring 213 and the T-shaped ring 212 are fixed. The clamping of the limiting ring 213 can achieve the sealing of the pipe. The T-shaped ring 212 is clamped by the third fixing member 305. The third clamping member 306 can clamp the T-shaped ring 212 and the limiting ring 213 through the third fixing member 305. Rotating the third threaded rod 309 causes the third extrusion ring 307 to move and extrude the third contact ring 308, which in turn extrudes the elastic ring pad 214, thereby sealing and extruding the gap between the two ductile iron pipes 1 to ensure the sealing effect. In the third embodiment, the T-shaped ring 212 and the limiting ring 213 cooperate to distribute pressure and avoid local deformation. This is suitable for ductile iron pipes 1 with bidirectional medium flow (such as circulation systems). Rotating the threaded rod 309 can adjust the sealing pressure in real time to compensate for wear.

[0059] Example 4

[0060] like Figure 5 As shown, the difference from Embodiment 1 above is that in this specific embodiment:

[0061] The sealing assembly 2 includes a gasket 216, which is disposed inside the ductile iron pipe 1. A movable ring 217 is provided on the outer wall of the gasket 216. A first washer 218 is provided on both sides of the movable ring 217. A second washer 219 is provided at one end of the ductile iron pipe 1. A trapezoidal member 220 is provided between the first washer 218 and the second washer 219.

[0062] The connecting assembly 3 includes a fourth fixing member 310, which is disposed outside the ductile iron pipe 1. An inclined ring member 323 for contacting the trapezoidal member 220 is fixedly connected inside the fourth fixing member 310. A fourth compression ring member 311 for restricting the moving ring 217 is also fixedly connected inside the fourth fixing member 310.

[0063] like Figure 5 As shown, considering that both ductile iron pipes 1 are already fixed, and to achieve the connection and seal between the two ductile iron pipes 1, the gasket 216 is first placed inside one of the ductile iron pipes 1 to align the ends of the two ductile iron pipes 1. The outer wall size of the gasket 216 and the inner wall size of the ductile iron pipe 1 are in a transition fit, so the gasket 216 can easily move inside the ductile iron pipe 1 while providing a sealing effect. To further enhance the sealing effect of the sealing structure, a groove (not marked in the figure) is provided on the outer wall of the gasket 216. A movable ring 217 is installed on the groove. The movable ring 217 is formed by two half-rings (not shown in the figure; this structure is a conventional solution in the field and will not be described in detail here) connected to each other. The groove restricts the position between the movable ring 217 and the gasket 216. Then, by setting the first washer 218 and the second washer 219, and... A trapezoidal member 220 is provided between the first washer 218 and the second washer 219. The trapezoidal member 220 will compress the first washer 218 and the second washer 219. Then, by installing the connecting component 3, the position of the moving ring 217 is restricted and the compression effect of the trapezoidal member 220 on the first washer 218 and the second washer 219 is guaranteed. By installing the fourth fixing member 310 and fixing the position of the moving ring 217 by the fourth compression ring member 311, the inclined ring member 323 applies force to the trapezoidal member 220, thereby causing the trapezoidal member 220 to apply force to the first washer 218 and the second washer 219 respectively, realizing compression sealing, thereby ensuring the sealing effect of the sealing structure of the entire ductile iron pipe. In embodiment four, the trapezoidal member 220 converts the axial force into the radial expansion force, which doubles the sealing efficiency. The moving ring 217 can be slidably installed, solving the docking problem of fixed pipes. The wedge structure of the inclined ring member 323 becomes tighter and tighter as it is pressed, thereby achieving anti-loosening.

[0064] Example 5

[0065] like Figure 6 As shown, the difference from Embodiment 1 above is that in this specific embodiment:

[0066] The sealing assembly 2 includes a fifth gasket 221, which is disposed between two ductile iron pipes 1. A fifth gasket 222 is provided on the outer wall of the ductile iron pipe 1.

[0067] The connecting assembly 3 includes a fifth sleeve 312, which is disposed on the outer wall of the ductile iron pipe 1. A connecting ring 313 is fixedly connected to the outer wall of the ductile iron pipe 1. The fifth sleeve 312 and the connecting ring 313 are connected by bolts and nuts (not marked in the figure). A collar 314 for pressing the fifth washer 222 is slidably connected inside the fifth sleeve 312. A fifth threaded rod 315 for pressing the collar 314 is threadedly connected to the inner wall of the fifth washer 222.

[0068] like Figure 6 As shown, a fifth washer 221 is installed between two ductile iron pipes 1. Then, pressure is applied to the fifth washer 221 by the fifth gasket 222. The fifth sleeve 312 is installed, and the fifth threaded rod 315 is rotated. The fifth threaded rod 315 and the connecting ring 313 move relative to each other. The position of the connecting ring 313 and the fifth sleeve 312 can be fixed by bolts and nuts. The collar 314 moves and applies force to the fifth washer 222 to achieve a seal. In embodiment five, the external sleeve 312 is connected to the fifth threaded rod 315, which is convenient to maintain, has a simple structure, and is suitable for low-pressure and non-corrosive media pipelines.

[0069] Example 6

[0070] like Figure 7 As shown, the difference from Embodiment 1 above is that in this specific embodiment:

[0071] The sealing assembly 2 includes a sixth washer 223, which is disposed on the outer wall of the ductile iron pipe 1, and a sixth gasket 224 is disposed on one side of the sixth washer 223.

[0072] The connecting assembly 3 includes a sixth sleeve 316, the inner wall of the sixth sleeve 316 is slidably connected to the outer wall of the ductile iron pipe 1, a sixth fixing ring 317 is fixedly connected to the inner wall of the ductile iron pipe 1, a sixth threaded rod 318 is threadedly connected to the inner thread of the sixth fixing ring 317, a sixth auxiliary sleeve 319 is installed between the sixth fixing ring 317 and the ductile iron pipe 1, and a sixth compression ring 320 is provided on one side of the sixth washer 223.

[0073] like Figure 7As shown, a sixth washer 223 is installed to wrap the gap between the two ductile iron pipes 1. Then, force is applied to both sides of the sixth washer 223 via the connecting assembly 3, causing the sixth washer 223 to be in a compressed state, thereby sealing the gap between the ductile iron pipes 1. When installing the sixth sleeve 316, the inner wall of the sixth sleeve 316 contacts one side of the sixth washer 223. Then, the sixth washer ring 224 is installed, and the sixth washer ring 224 contacts the other side of the sixth washer 223. Finally, the sixth threaded rod 318 is rotated, and the sixth fixing ring 317 and... The sixth threaded rod 318 moves relative to the sixth threaded rod, causing the sixth threaded rod 318 to apply force to the sixth washer 224 through the sixth extrusion ring 320. The sixth auxiliary sleeve 319 can protect the sixth threaded rod 318 and apply force to the sixth washer 224, thereby achieving extrusion on both sides of the sixth washer 223. The sixth sleeve 316 is formed by two sixth plate sleeves connected to each other. In embodiment six, the sixth washer 223 covers the entire interface to prevent the intrusion of external corrosive media. The sixth auxiliary sleeve 319 ensures that the extrusion force is evenly distributed and avoids the twisting of the sixth washer 223.

[0074] Example 7

[0075] like Figure 8 As shown, the difference from Embodiment 1 above is that in this specific embodiment:

[0076] The sealing assembly 2 includes a seventh washer 225, which is disposed on the outer wall of the ductile iron pipe 1.

[0077] The connecting assembly 3 includes a seventh sleeve 321, which is installed on the outer wall of the ductile iron pipe 1. A seventh extrusion ring 322 for extruding the seventh washer 225 is fixedly connected inside the seventh sleeve 321.

[0078] like Figure 8 As shown, compared with Embodiment 6, Embodiment 6 achieves sealing by wrapping the gap, while Embodiment 7 directly seals the gap. The seventh washer 225 is placed between the two sleeves, and then the seventh washer 225 is squeezed by the connecting component 3. The seventh sleeve 321 is installed and the seventh extrusion ring 322 applies force to the seventh washer 225, thereby achieving sealing of the gap of the ductile iron pipe 1. Embodiment 7 has fewer parts, lower cost and faster installation.

[0079] There are several scenarios when connecting ductile iron pipes. One scenario involves one ductile iron pipe 1 being fixed in position while the other is free and can move arbitrarily within a certain range. Another scenario involves both ductile iron pipes 1 being fixed, and then connecting and sealing them together. Furthermore, the actual use of ductile iron pipes 1 can vary; the flow medium inside some ductile iron pipes 1 may be unidirectional or bidirectional. Therefore, the unidirectional nature of the internal flow medium of the ductile iron pipe 1 needs to be considered. Examples one through seven described above are used to achieve the connection of two ductile iron pipes 1 under various conditions.

[0080] For example:

[0081] In Embodiment 1, the first sealing inner ring 201 is placed inside the ductile iron pipe 1 first, and then the first sealing inner ring 201 is moved to achieve a preliminary connection between the two ductile iron pipes 1 that are fixed in position.

[0082] In the second embodiment, by placing the first elastic pad 206 and the hollow support 207 inside a ductile iron pipe 1, and then adjusting the thickness of the annular washer 209 (which can be considered as a combination of multiple annular washers 209), the gap between the two ductile iron pipes 1 is adapted, and the initial connection between the two fixed ductile iron pipes 1 is completed.

[0083] In Example 4, the ring gasket 216 is placed into one of the ductile iron pipes 1 as in Example 1, and then the ring gasket 216 is moved to achieve a preliminary connection between the two ductile iron pipes 1. Through the above examples, the connection between two ductile iron pipes 1 that have been fixed in position can be effectively completed.

[0084] Through the design of sealing structures in multiple embodiments, it is possible to adapt to installation scenarios where one ductile iron pipe 1 is fixed and the other ductile iron pipe 1 is free to move, as well as docking installation scenarios where both ductile iron pipes 1 are fixed, thereby improving the flexibility and convenience of installation. At the same time, corresponding sealing structures are provided to address the unidirectional and bidirectional nature of the internal flow medium of the ductile iron pipe 1, ensuring a reliable sealing effect under different flow directions and guaranteeing installation efficiency.

[0085] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended embodiments and their equivalents.

Claims

1. A sealing structure for a ductile iron pipe, characterized in that: It includes a sealing assembly (2) disposed between two ductile iron pipes (1), and a connecting assembly (3) connecting the two ductile iron pipes (1). The sealing assembly (2) includes a second elastic pad (211), which is disposed inside the ductile iron pipe (1). A T-shaped ring (212) is fixedly connected inside the second elastic pad (211). A limiting ring (213) is disposed on the outer wall of the T-shaped ring (212). An elastic ring pad (214) is disposed between the limiting ring (213) and the second elastic pad (211). The gap between the second elastic pad (211) and the T-shaped ring (212) is filled with a second curing agent (215). The connecting assembly (3) includes a third fixing member (305), which is disposed on the outer wall of the ductile iron pipe (1). The third fixing member (305) is fixedly connected to a third clamping member (306) for clamping the limiting ring (213). The inner wall of the third fixing member (305) is slidably connected to a third extrusion ring (307). A third contact ring (308) is disposed between the third extrusion ring (307) and the third clamping member (306). The inner thread of the third fixing member (305) is threadedly connected to a third threaded rod (309) for extruding the third extrusion ring (307).

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