A pressure-maintaining type double-layer pipe
By embedding a tracer wire structure within a double-layer PE pipe and utilizing a dual-cylinder and rust-proof design, the problems of tracer wire breakage and rusting are solved, ensuring the strength of the detection signal and achieving low-cost protection and automatic grounding functions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NINGBO YUHUA ELECTRIC APPLIANCE CO LTD
- Filing Date
- 2023-09-01
- Publication Date
- 2026-07-21
AI Technical Summary
The existing tracer wire structure is prone to breakage when backfilling the pipeline or when there is ground subsidence, and the tracer grounding section is prone to rust, resulting in excessive grounding circuit resistance and weak detection feedback signal.
It adopts a pressure-holding double-layer pipe structure, with a pressure-holding cavity formed between the inner and outer PE pipes. It has a built-in tracer line structure, including a tracer application section, a routing section, and a pre-concealed section. It utilizes a double cylinder structure and rust-proof protection design to ensure that the tracer line is not exposed. It automatically grounds after the outer layer is damaged, providing rust protection.
It effectively prevents tracer wire breakage and rust, ensures low grounding loop resistance, guarantees strong detection feedback signal, has a low-cost and suitable protection structure, and can automatically adjust the grounding state.
Smart Images
Figure CN117006325B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of PE pipe technology, and particularly relates to a pressure-insulating double-layer pipe. Background Technology
[0002] Double-layer PE pipes are a common type of non-metallic pipe widely used in natural gas and oil transportation. The inner layer of a double-layer PE pipe carries the medium, while the outer layer is filled with nitrogen as a protective gas, and is equipped with pressure detection and alarm devices. During normal operation, the pressure of the medium inside the inner layer is higher than that of the protective gas, thus balancing the pressure between the inner and outer layers and protecting the inner layer. If the outer layer is damaged, the pressure detection device will detect a significant pressure change between the outer and inner layers, triggering the alarm. This allows for timely repairs and maintenance (the outer layer is more likely to break first than the inner layer, and even if only the inner layer breaks, there is usually sufficient time for repairs, preventing leakage).
[0003] PE pipes are mostly laid underground, making them difficult to detect once buried. When external forces damage the outer or even inner layer of the pipe, rapid detection of its direction and location is crucial, necessitating a tracer system. The tracer system works by laying a metal wire along the pipe and using the magnetic field changes generated by current passing through the wire (detected by a detector) to pinpoint the wire's location and thus the pipe's position. One common method for applying current to the tracer is the active source method, which directly applies current to the system. This requires not only the metal wire laid along the pipe but also a wire connected to the ground and a grounded wire; otherwise, successful detection is impossible. Currently, the more common practice is to install a metal wire (tracing direction section) along the pipeline route outside the pipeline, a metal wire (tracing application section) at the ground surface, and a metal wire (tracing grounding section) underground for grounding. The lower end of the tracing application section is connected to one end of the tracing direction section, and the tracing grounding section is connected to the other end of the tracing direction section. The tracing application section needs to have an exposed end point (the exposed end point needs to be at the ground surface and can be easily exposed for applying the detection current signal). The tracing grounding section forms a loop with the ground (usually the soil at the buried pipe location), and it needs to be long enough to avoid excessive loop resistance that would result in a weak feedback signal. The length of the grounding metal wire should usually be no less than 15 cm (the greater the loop resistance, the weaker the signal).
[0004] However, in existing technologies, the selection of tracer wires also requires consideration of factors such as strength and corrosion resistance. If the tracer wire is not strong enough, it is prone to breaking and becoming ineffective when backfilling the pipeline or when there is ground subsidence. The outer sheath of the tracer wire (mostly plastic sheath) may also crack due to aging, causing more of the tracer wire to be exposed in the soil. The exposed tracer wire (especially the tracer grounding section that needs to be exposed from beginning to end) is prone to rusting. Once rusted, its conductivity is greatly reduced, which leads to excessive grounding loop resistance and insufficient feedback signal during detection. Summary of the Invention
[0005] This invention provides a pressure-holding double-layer pipe that can solve the problem of conventional tracer structures being prone to breakage when backfilling the pipeline or when there is ground subsidence. It also provides rust protection for the tracer structure. More importantly, it replaces the tracer grounding section, which needs to be exposed all the time, with a tracer pre-concealed section that is not exposed under normal circumstances. When the outer PE pipe is damaged, the tracer pre-concealed section can be automatically grounded, which ensures that the grounding circuit resistance is not too high from multiple aspects, thus ensuring that the feedback signal during detection is strong enough.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: A pressure-holding double-layer pipe includes an inner PE pipe, an outer PE pipe, a tracer line structure, and a double-cylinder structure. The inner PE pipe is located inside the outer PE pipe, and a pressure-holding cavity is formed between the inner and outer PE pipes. A support body is provided inside the pressure-holding cavity. The support body is fixed to the outer PE pipe and the inner PE pipe. The tracer line structure includes a tracer application section, a tracer direction section, and a tracer pre-concealment section. The tracer direction section is located inside the pressure-holding cavity. The outer PE pipe is provided with a surface pipe, which passes through the outer PE pipe and is sealed and fixed to the outer PE pipe. The lower end of the surface pipe is provided with a fixed sealing end cap located in the pressure holding cavity, and the upper end of the surface pipe is provided with an openable sealing end cap. The tracer application section passes through the fixed sealing end cap and is sealed and fixed to the fixed sealing end cap. One end of the tracer application section is connected to the tracer direction section. The dual-cylinder structure includes a contact cylinder and a transfer cylinder. The contact cylinder is equipped with a contact piston. The interior of the contact cylinder is divided into a high-pressure contact chamber and a low-pressure contact chamber by the contact piston. A compression spring is provided in the low-pressure contact chamber. A conductive piston rod passes through the inner contact piston and is sealed and fixed with the inner contact piston. The conductive piston rod passes through the high-pressure contact chamber. The conductive piston rod is slidably sealed with the contact cylinder. The conductive piston rod is provided with a push-out tip for breaking the soil. The contact cylinder passes through the outer PE pipe and is sealed and fixed to the outer PE pipe. The inner end of the contact cylinder is located in the pressure holding chamber. The contact cylinder is provided with a fixed wire that passes through the inner end of the contact cylinder and is sealed and fixed to the inner end of the contact cylinder. The contact high pressure chamber is provided with a redundant wire. One end of the fixed wire is connected to the tracer direction section, and the other end of the fixed wire is connected to one end of the redundant wire. The other end of the redundant wire is connected to the conductive piston rod. The transfer cylinder passes through the outer PE pipe and is sealed and fixed to the outer PE pipe. The inner end of the transfer cylinder is located in the pressure holding chamber. The transfer cylinder is provided with a transfer inner through hole that communicates with the pressure holding chamber. The transfer cylinder is connected to the contact high pressure chamber through a double connecting pipe located outside the outer PE pipe. The fixed wire, redundant wire, and conductive piston rod together constitute the tracer pre-concealment segment.
[0007] Preferably, the outer end of the contact cylinder is provided with a rust-proof sleeve and a rust-proof thin cover. One end of the rust-proof sleeve is sealed and fixed to the outer end of the contact cylinder, and the rust-proof thin cover seals the other end of the rust-proof sleeve. The ejection tip is located inside the rust-proof sleeve, and the part of the conductive piston rod outside the contact cylinder is located inside the rust-proof sleeve. There is a protective gap between the ejection tip and the rust-proof thin cover.
[0008] Preferably, the high-pressure contact chamber is provided with a limiting block for limiting the contact piston. The double connecting pipe is connected to the high-pressure contact chamber through a contact through hole provided on the contact cylinder. When the contact piston contacts the limiting block: the compression spring, the contact piston and the contact through hole are arranged in sequence along the sliding direction of the contact piston. The length of the conductive piston rod outside the contact cylinder is M centimeters, and the length of the conductive piston rod inside the anti-rust sleeve is N centimeters, where MN is greater than 20.
[0009] Preferably, the openable sealing end cap is threaded to the surface pipe, the inner diameter of the surface pipe is 5 to 10 times the diameter of the tracer application section, and the distance between the openable sealing end cap and the upper end of the tracer application section is less than 15 cm.
[0010] Preferably, the tracer application section, the tracer direction section, and the fixed wire are all made of hard-core copper wire, and the redundant wire is made of copper wire. The hard-core copper wire includes an outer copper sheath and an inner steel core. The length of the contact low-pressure cavity in the sliding direction of the contact piston is greater than 20 cm. When the redundant wire is straightened, the length of the redundant wire is greater than 40 cm.
[0011] Preferably, the support includes at least one ring plate with several large ventilation holes. The outer ring of the ring plate is fixed to the inner wall of the outer PE pipe, and the inner ring of the ring plate is fixed to the outer wall of the inner PE pipe. The tracer direction segment is parallel to the axial direction of the outer PE pipe and passes through the ring plate and is fixed to the ring plate.
[0012] Preferably, the contact cylinder is arranged vertically, with its inner end being the upper end and its outer end being the lower end. The transfer cylinder is also arranged vertically, with its inner end being the upper end and its outer end being the lower end. The lower end of the contact cylinder is located below the bottom of the outer PE pipe, and the lower end of the transfer cylinder is located below the bottom of the outer PE pipe. The double-connecting pipe is located below the bottom of the outer PE pipe.
[0013] Preferably, it also includes an external support member, which includes a vertical mesh cylinder and a pair of arc plates that abut against the bottom of the outer PE pipe. The arc plates are fixed to the top of the vertical mesh cylinder. The lower end of the contact cylinder is located inside the vertical mesh cylinder. The lower end of the transfer cylinder is located inside the vertical mesh cylinder. The double connecting pipe is located inside the vertical mesh cylinder.
[0014] Preferably, a pre-inflatable airbag is provided on the inner wall of the vertical mesh cylinder, and an initiating inflatable airbag that can be punctured by the push-out tip is fixed inside the vertical mesh cylinder. The initiating inflatable airbag is fixed to the inner wall of the vertical mesh cylinder and is connected to the pre-inflatable airbag. The volume of the pre-inflatable airbag is 10 to 30 times the volume of the initiating inflatable airbag. When the conductive piston rod extends to the limit position: the outer end of the contact cylinder, the pre-inflatable airbag and the push-out tip are arranged in sequence along the sliding direction of the contact piston, and the distance between the pre-inflatable airbag and the conductive piston rod is less than 3 cm.
[0015] Preferably, the transfer cylinder is equipped with a pressure-dividing cylinder, and the pressure-dividing cylinder is provided with a pressure-dividing pipe that passes through the side wall of the contact cylinder and is sealed and fixed to the side wall of the contact cylinder. One end of the pressure-dividing pipe is connected to the pressure-dividing cylinder, and the other end of the pressure-dividing pipe is connected to the contact low-pressure chamber. The part of the pressure-dividing pipe outside the contact cylinder is located outside the outer PE pipe.
[0016] The beneficial effects of this invention are: it can solve the problem of conventional tracer line structures being prone to breakage when backfilling pipelines or when there is ground subsidence, and it can provide rust protection for the tracer line structure. More importantly, it replaces the tracer grounding section, which needs to be exposed all the time, with a tracer pre-concealed section that is not exposed under normal circumstances. When the outer PE pipe is damaged, the tracer pre-concealed section can be automatically grounded, which ensures that the grounding circuit resistance is not too high from multiple aspects, thus ensuring that the feedback signal during detection is strong enough; it has a low-cost and suitable protection structure that can effectively support and protect pipelines and critical structures; and it has a pre-set avoidance structure that makes the movement of the conductive piston rod easier and smoother. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 2 yes Figure 1 Enlarged view of point A in the middle; Figure 3 yes Figure 1 Enlarged view of point B in the middle; Figure 4 This is a schematic diagram of the structure of Embodiment 2 of the present invention; Figure 5 yes Figure 4 Enlarged view of point C in the middle; Figure 6 This is a cross-sectional view of Embodiment 2 of the present invention; Figure 7 yes Figure 6 Enlarged view of point D in the middle; Figure 8 yes Figure 6 Enlarged view at point E in the middle; Figure 9 yes Figure 7 Enlarged view of point F in the middle.
[0018] Reference numerals: Inner PE pipe 1, Outer PE pipe 2, Pressure holding chamber 2a, Ring plate 201, Large vent 201a, Tracer application section 301, Tracer direction section 302, Tracer pre-concealment section 303, Surface pipe 4, Fixed sealing end cap 401, Openable sealing end cap 402, Contact cylinder 501, Contact piston 501.1, Compression spring 501.2, Limiting block 501.3, Contact high pressure chamber 501 a. Low-pressure contact chamber 501b. Transfer cylinder 502. Transfer inner through hole 502a. Conductive piston rod 503. Push-out tip 503.1. Fixed wire 504. Redundant wire 505. Double connecting pipe 506. Pressure dividing cylinder 507. Rust-proof sleeve 601. Rust-proof thin cover 602. Vertical mesh cylinder 701. Cylinder through hole 701a. Arc plate 702. Pre-set elastic airbag 703. Initiation inflation airbag 704. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1:
[0020] like Figures 1 to 3 As shown, a pressure-holding double-layer pipe includes an inner PE pipe 1, an outer PE pipe 2, a tracer line structure, and a double-cylinder structure. The inner PE pipe 1 is located inside the outer PE pipe 2, and a pressure-holding cavity 2a is formed between the inner PE pipe 1 and the outer PE pipe 2. A support body is provided in the pressure-holding cavity 2a. The support body is fixed to the outer PE pipe 2 and the inner PE pipe 1. The tracer line structure includes a tracer application section 301, a tracer direction section 302, and a tracer pre-concealment section 303. The tracer direction section 302 is located in the pressure-holding cavity 2a. The outer PE pipe 2 is provided with a surface pipe 4, which passes through the outer PE pipe 2 and is sealed and fixed to the outer PE pipe 2. The lower end of the surface pipe 4 is provided with a fixed sealing end cap 401 located in the pressure holding chamber 2a, and the upper end of the surface pipe 4 is provided with an openable sealing end cap 402. The tracer application section 301 passes through the fixed sealing end cap 401 and is sealed and fixed to the fixed sealing end cap 401. One end of the tracer application section 301 is connected to the tracer direction section 302. The dual-cylinder structure includes a contact cylinder 501 and a transfer cylinder 502. The contact cylinder 501 is equipped with a contact piston 501.1. The contact cylinder 501 is divided into a high-pressure contact chamber 501a and a low-pressure contact chamber 501b by the contact piston 501.1. A compression spring 501.2 is provided in the low-pressure contact chamber 501b. A conductive piston rod hole 503 passes through the inner contact piston and is sealed and fixed with the inner contact piston. The conductive piston rod hole 503 passes through the high-pressure contact chamber 501a. The conductive piston rod hole 503 is slidably sealed with the contact cylinder 501. The conductive piston rod hole 503 is equipped with a push-out tip 503.1 for breaking the soil. One end of the compression spring 501.2 presses against the contact piston 501.1, and the other end of the compression spring 501.2 presses against the inner end of the contact cylinder 501; The contact cylinder 501 passes through the outer PE pipe 2 and is sealed and fixed to the outer PE pipe 2. The inner end of the contact cylinder 501 is located in the pressure holding chamber 2a. The contact cylinder 501 is provided with a fixed wire 504 that passes through the inner end of the contact cylinder 501 and is sealed and fixed to the inner end of the contact cylinder 501. The contact high pressure chamber 501a is provided with a redundant wire 505. One end of the fixed wire 504 is connected to the tracer direction section 302, and the other end of the fixed wire 504 is connected to one end of the redundant wire 505. The other end of the redundant wire 505 is connected to the conductive piston rod hole 503. The transfer cylinder 502 passes through the outer PE pipe 2 and is sealed and fixed to the outer PE pipe 2. The inner end of the transfer cylinder 502 is located in the pressure holding chamber 2a. The transfer cylinder 502 is provided with a transfer inner through hole 502a that communicates with the pressure holding chamber 2a. The transfer cylinder 502 is connected to the contact high pressure chamber 501a through a double connecting pipe 506 located outside the outer PE pipe 2. The fixed wire 504, the redundant wire 505, and the conductive piston rod hole 503 together constitute the tracer pre-concealment section 303.
[0021] The inner PE pipe 1 is used to transport the medium. The pressure holding chamber 2a is filled with nitrogen. The pressure in the low-pressure contact chamber 501b is lower than the pressure in the high-pressure contact chamber 501a (for example, the nitrogen pressure can be 3 times the medium pressure, and the pressure in the low-pressure contact chamber 501b can be close to the medium pressure. Specifically, it can be selected according to the medium pressure, actual needs, etc.).
[0022] The tracer application section 301 in the tracer wire structure is protected by the surface pipe 4. When the tracer application section 301 needs to be used, the openable sealing end cap 402 can be opened. The tracer routing section 302 in the tracer wire structure is protected by the outer PE pipe 2. The tracer pre-concealment section 303 in the tracer wire structure is protected by the contact cylinder 501. In this way, the parts of the tracer wire structure that conduct electricity during detection are protected against rust. Furthermore, due to the existence of the relevant protective structures, the tracer wire structure no longer requires the wire sheath of a traditional tracer wire and can use bare wire.
[0023] When the outer tube is damaged due to external force, nitrogen leaks from the pressure-holding chamber 2a. The contact high-pressure chamber 501a, the double-connecting pipe 506, the transfer cylinder 502, and the pressure-holding chamber 2a are connected. Therefore, the air pressure in the contact high-pressure chamber 501a drops significantly in a short time. Under the action of the compression spring 501.2, the contact inner piston, the conductive piston rod hole 503, and the push-out tip 503.1 move outward together. During this movement, the push-out tip 503.1 and the conductive piston rod hole 503 can push away the surrounding soil. The redundant wire 505 connected to the conductive piston rod hole 503 will be "straightened" slightly until the conductive piston rod hole 503 extends to its limit position. A large section of the conductive piston rod hole 503, which is normally not in contact with the outside, is now in contact with the soil and can be used as a grounding wire. Furthermore, the part of the conductive piston rod hole 503 that is normally not in contact with the outside is not rusted, thus ensuring that the grounding circuit resistance is not too high, and therefore ensuring a sufficiently strong feedback signal during detection. The testing personnel can directly open the openable sealed end cover 402 and apply a detection current signal to the tracer application section 301 to perform the test.
[0024] The outer end of the contact cylinder 501 is provided with a rust-proof sleeve 601 and a rust-proof thin cover 602. One end of the rust-proof sleeve 601 is sealed and fixed to the outer end of the contact cylinder 501, and the rust-proof thin cover 602 seals the other end of the rust-proof sleeve 601. The push-out tip 503.1 is located inside the rust-proof sleeve 601, and the part of the conductive piston rod hole 503 outside the contact cylinder 501 is located inside the rust-proof sleeve 601. There is a protective gap between the push-out tip 503.1 and the rust-proof thin cover 602.
[0025] This solution further protects the conductive piston rod hole 503. Normally, the conductive piston rod hole 503 is completely isolated from the outside world, which can prevent the conductive piston rod hole 503 from rusting. When the conductive piston rod hole 503 begins to extend outward, the protruding tip 503.1 will pierce the anti-rust thin cover 602 before breaking the soil.
[0026] The rust-proof sleeve 601 is made of PE plastic, and the rust-proof thin cap 602 is also made of PE plastic. The tracing direction section 302 follows the same direction as the outer PE pipe 2.
[0027] The high-pressure contact chamber 501a is provided with a limiting block 501.3 for limiting the contact piston 501.1. The double connecting pipe 506 is connected to the high-pressure contact chamber 501a through the contact through hole provided on the contact cylinder 501. When the contact piston 501.1 contacts the limiting block 501.3: the compression spring 501.2, the contact piston 501.1 and the contact through hole are arranged in sequence along the sliding direction of the contact piston 501.1. The length of the part of the conductive piston rod hole 503 outside the contact cylinder 501 is M centimeters, and the length of the part of the conductive piston rod hole 503 inside the anti-rust sleeve 601 is N centimeters, where MN is greater than 20.
[0028] When the conductive piston rod hole 503 extends to its limit position, the contact piston 501.1 contacts the limiting block 501.3. At this time, the length of the portion of the conductive piston rod hole 503 in contact with the soil is greater than 20 cm. This is because the tracer structure forms a loop with the ground. If the contact length between the conductive piston rod hole 503 and the soil is too short, the loop resistance will be too high. Therefore, the contact length is set to be greater than 20 cm.
[0029] The openable sealing end cap 402 is threadedly connected to the surface pipe 4. The inner diameter of the surface pipe 4 is 5 to 10 times the diameter of the tracer application section 301. The distance between the openable sealing end cap 402 and the upper end of the tracer application section 301 is less than 15 cm.
[0030] If the inner diameter of the surface pipe 4 is too small, there will be insufficient space, which will not be conducive to the operation of applying the detection current signal. Taking all factors into consideration, it is selected that "the inner diameter of the surface pipe 4 is 5 to 10 times the diameter of the tracer application section 301". If the upper end of the tracer application section 301 is too deep or too low, it will also not be conducive to the operation of applying the detection current signal. Taking all factors into consideration, it is selected that "the distance between the openable sealing end cap 402 and the upper end of the tracer application section 301 is less than 15 cm".
[0031] The tracer application section 301, the tracer direction section 302, and the fixed wire 504 are all made of hard-core copper wire. The redundant wire 505 is made of copper wire. The hard-core copper wire includes an outer copper sheath and an inner steel core. The length of the contact low-pressure cavity 501b in the sliding direction of the contact piston 501.1 is greater than 20 cm. When the redundant wire 505 is straightened, the length of the redundant wire 505 is greater than 40 cm.
[0032] The redundant conductor 505 should be long enough to ensure that it can be adaptively straightened (not absolutely straightened, but straightened more than before) when the conductive piston rod hole 503 moves. The inner steel core of the hard-core copper wire acts as a "skeleton" to protect and maintain the shape of the outer copper sheath, which is mainly used for conduction. Considering the skin effect, this structure is quite reasonable.
[0033] The support includes at least one ring plate 201, on which a plurality of large vent holes 201a are provided. The outer ring of the ring plate 201 is fixed to the inner wall of the outer PE pipe 2, and the inner ring of the ring plate 201 is fixed to the outer wall of the inner PE pipe 1. The tracer directional section 302 is parallel to the axial direction of the outer PE pipe 2, and the tracer directional section 302 passes through the ring plate 201 and is fixed to the ring plate 201.
[0034] The ring plate 201 is used to support, connect and reinforce the outer PE pipe 2 and the inner PE pipe 1. The ring plate 201 can also help fix or position the tracer direction section 302 to ensure its direction is stable (the direction of the tracer direction section 302 is basically consistent with the direction of the outer PE pipe 2).
[0035] The contact cylinder 501 is arranged vertically, with its inner end being the upper end and its outer end being the lower end. The transfer cylinder 502 is also arranged vertically, with its inner end being the upper end and its outer end being the lower end. The lower end of the contact cylinder 501 is located below the bottom of the outer PE pipe 2, and the lower end of the transfer cylinder 502 is also located below the bottom of the outer PE pipe 2. The double connecting pipe 506 is located below the bottom of the outer PE pipe 2.
[0036] When subjected to external force, the top and sides of the PE pipe are more likely to come into contact with the source of damage (such as digging through the PE pipe during excavation). It is obviously more appropriate to place important structures such as the double cylinder structure at the bottom of the outer PE pipe 2, which is less susceptible to damage. Example 2:
[0037] Based on Example 1, such as Figures 4 to 9 As shown, it also includes an outer support component, which includes a vertical mesh cylinder 701 and a pair of arc plates 702 that abut against the bottom of the outer PE pipe 2. The arc plates 702 are fixed to the top of the vertical mesh cylinder 701. The lower end of the contact cylinder 501 is located inside the vertical mesh cylinder 701, the lower end of the transfer cylinder 502 is located inside the vertical mesh cylinder 701, and the double connecting pipe 506 is located inside the vertical mesh cylinder 701. The vertical mesh cylinder 701 has multiple through holes 701a.
[0038] Background art indicates that, under normal circumstances, when selecting a tracer wire, factors such as strength must be considered. If the tracer wire is not strong enough, it is prone to breakage and failure during pipeline backfilling or ground subsidence. In this invention, although the tracer wire structure is "built-in," the corresponding protective structures for protecting the tracer wire structure, as well as critical structures such as the grounding portion of the tracer wire structure, still deserve protection (mainly at the double-cylinder structure). This embodiment adopts a low-cost solution, using a vertical mesh cylinder 701 to "frame" the critical structures. Before pipeline backfilling, some loose soil can be prefilled inside the vertical mesh cylinder 701 before installing the pipeline and other structures. This prevents the critical structures from being damaged during pipeline backfilling, and effectively supports and protects the pipeline and critical structures in subsequent use, such as when surrounding soil compresses the critical structures or ground subsidence occurs. Furthermore, the vertical mesh cylinder 701, in conjunction with the arc plate 702, can better support the outer PE pipe 2.
[0039] A pre-placed elastic airbag 703 is provided on the inner wall of the vertical mesh cylinder 701. An induction airbag 704 that can be punctured by the push-out tip 503.1 is fixed inside the vertical mesh cylinder 701. The induction airbag 704 is fixed to the inner wall of the vertical mesh cylinder 701 and is connected to the pre-placed airbag. The volume of the pre-placed airbag is 10 to 30 times the volume of the induction airbag 704. When the conductive piston rod hole 503 extends to the limit position: the outer end of the contact cylinder 501, the pre-placed airbag and the push-out tip 503.1 are arranged in sequence along the sliding direction of the contact piston 501.1. The distance between the pre-placed airbag and the conductive piston rod hole 503 is less than 3 cm.
[0040] Due to factors such as construction and ground subsidence, the present invention may be subject to compression from the surrounding soil, causing the soil at the double-cylinder structure to become increasingly compacted, which is detrimental to the extension of the conductive piston rod hole 503. Therefore, in this solution, when the conductive piston rod hole 503 extends, the protruding tip 503.1 pierces the anti-rust thin cover 602, and then first pierces the initiating inflation airbag 704 before pushing away the soil. After the initiating inflation airbag 704 is pierced, the pre-placed inflation airbag, located less than 3 cm to the side of the conductive piston rod hole 503 and connected to it, will shrink, thus providing some space for the soil to move. This helps the protruding tip 503.1 and the conductive piston rod hole 503 to better push and squeeze away the soil, allowing the conductive piston rod hole 503 to ground smoothly.
[0041] The Qifa inflatable airbag 704 is sealed and fixed to the lower end of the rust-proof sleeve 601, and the rust-proof thin cover 602 is covered by the Qifa inflatable airbag 704. The Qifa inflatable airbag 704 can protect the rust-proof thin cover 602, which has relatively weak strength and limited deformation ability.
[0042] The transfer cylinder 502 is equipped with a pressure dividing cylinder 507. The pressure dividing cylinder 507 is provided with a pressure dividing pipe that passes through the side wall of the contact cylinder 501 and is sealed and fixed to the side wall of the contact cylinder 501. One end of the pressure dividing pipe is connected to the pressure dividing cylinder 507, and the other end of the pressure dividing pipe is connected to the contact low pressure chamber 501b. The part of the pressure dividing pipe outside the contact cylinder 501 is located outside the outer PE pipe 2.
[0043] When the conductive piston rod hole 503 moves outward, the air pressure in the contact piston 501.1 will decrease because the contact low-pressure chamber 501b also moves outward. If the volume of the contact low-pressure chamber 501b is too small, the air pressure change in the contact low-pressure chamber 501b will be too large, which is not conducive to the smooth movement of the contact piston 501.1. Therefore, a pressure-dividing cylinder 507 connected to the contact low-pressure chamber 501b is set up to make the movement of the contact piston 501.1 easier and smoother.
[0044] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A pressure-holding double-layer pipe, characterized in that, The device includes an inner PE pipe (1), an outer PE pipe (2), a tracer line structure, and a double cylinder structure. The inner PE pipe (1) is located inside the outer PE pipe (2). A pressure-holding cavity (2a) is formed between the inner PE pipe (1) and the outer PE pipe (2). A support body is provided in the pressure-holding cavity (2a). The support body is fixed to the outer PE pipe (2) and the support body is fixed to the inner PE pipe (1). The tracer line structure includes a tracer application section (301), a tracer direction section (302), and a tracer pre-concealment section (303). The tracer direction section (302) is located in the pressure-holding cavity (2a). The outer PE pipe (2) is provided with a surface pipe (4), which passes through the outer PE pipe (2) and is sealed and fixed to the outer PE pipe (2). The lower end of the surface pipe (4) is provided with a fixed sealing end cap (401) located in the pressure holding chamber (2a), and the upper end of the surface pipe (4) is provided with an openable sealing end cap (402). The tracer application section (301) passes through the fixed sealing end cap (401) and is sealed and fixed to the fixed sealing end cap (401). One end of the tracer application section (301) is connected to the tracer direction section (302). The dual-cylinder structure includes a contact cylinder (501) and a transfer cylinder (502). The contact cylinder (501) is equipped with a contact piston (501.1). The contact cylinder (501) is divided into a high-pressure contact chamber (501a) and a low-pressure contact chamber (501b) by the contact piston (501.1). A compression spring (501.2) is provided in the low-pressure contact chamber (501b). A conductive piston rod hole (503) passes through the contact piston and is sealed and fixed with the contact piston. The conductive piston rod hole (503) passes through the high-pressure contact chamber (501a). The conductive piston rod hole (503) is slidably sealed with the contact cylinder (501). The conductive piston rod hole (503) is equipped with a push-out tip (503.1) for breaking the soil. The contact cylinder (501) passes through the outer PE pipe (2) and is sealed and fixed to the outer PE pipe (2). The inner end of the contact cylinder (501) is located in the pressure holding chamber (2a). The contact cylinder (501) is provided with a fixed wire (504) that passes through the inner end of the contact cylinder (501) and is sealed and fixed to the inner end of the contact cylinder (501). The contact high pressure chamber (501a) is provided with a redundant wire (505). One end of the fixed wire (504) is connected to the tracer direction section (302), and the other end of the fixed wire (504) is connected to one end of the redundant wire (505). The other end of the redundant wire (505) is connected to the conductive piston rod hole (503). The transfer cylinder (502) passes through the outer PE pipe (2) and is sealed and fixed to the outer PE pipe (2). The inner end of the transfer cylinder (502) is located in the pressure holding chamber (2a). The transfer cylinder (502) is provided with a transfer inner through hole (502a) that communicates with the pressure holding chamber (2a). The transfer cylinder (502) is connected to the contact high pressure chamber (501a) through a double connecting pipe (506) located outside the outer PE pipe (2). The fixed wire (504), redundant wire (505), and conductive piston rod hole (503) together constitute the tracer pre-hidden segment (303).
2. The pressure-retaining double-layer pipe according to claim 1, characterized in that, The outer end of the contact cylinder (501) is provided with a rust-proof sleeve (601) and a rust-proof thin cover (602). One end of the rust-proof sleeve (601) is sealed and fixed to the outer end of the contact cylinder (501). The rust-proof thin cover (602) seals the other end of the rust-proof sleeve (601). The push-out tip (503.1) is located inside the rust-proof sleeve (601). The part of the conductive piston rod hole (503) outside the contact cylinder (501) is located inside the rust-proof sleeve (601). There is a protective gap between the push-out tip (503.1) and the rust-proof thin cover (602).
3. The pressure-retaining double-layer pipe according to claim 2, characterized in that, The high-pressure contact chamber (501a) is provided with a limiting block (501.3) for limiting the contact piston (501.1). The double connecting pipe (506) is connected to the high-pressure contact chamber (501a) through the contact through hole provided on the contact cylinder (501). When the contact piston (501.1) contacts the limiting block (501.3): the compression spring (501.2), the contact piston (501.1) and the contact through hole are arranged in sequence along the sliding direction of the contact piston (501.1). The length of the part of the conductive piston rod hole (503) outside the contact cylinder (501) is M centimeters, and the length of the part of the conductive piston rod hole (503) inside the anti-rust sleeve (601) is N centimeters. MN is greater than 20.
4. A pressure-retaining double-layer pipe according to claim 1, 2, or 3, characterized in that, The openable sealing end cap (402) is threadedly connected to the surface pipe (4). The inner diameter of the surface pipe (4) is 5 to 10 times the diameter of the tracer application section (301). The distance between the openable sealing end cap (402) and the upper end of the tracer application section (301) is less than 15 cm.
5. A pressure-retaining double-layer pipe according to claim 1, 2, or 3, characterized in that, The tracer application section (301), tracer direction section (302) and fixed wire (504) are all made of hard-core copper wire. The redundant wire (505) is made of copper wire. The hard-core copper wire includes an outer copper sheath and an inner steel core. The length of the contact low-pressure cavity (501b) in the sliding direction of the contact piston (501.1) is greater than 20 cm. When the redundant wire (505) is straightened, the length of the redundant wire (505) is greater than 40 cm.
6. A pressure-retaining double-layer pipe according to claim 1, 2, or 3, characterized in that, The support includes at least one ring plate (201), the ring plate (201) is provided with a plurality of large ventilation holes (201a), the outer ring of the ring plate (201) is fixed to the inner wall of the outer PE pipe (2), the inner ring of the ring plate (201) is fixed to the outer wall of the inner PE pipe (1), the tracer direction section (302) is parallel to the axial direction of the outer PE pipe (2), the tracer direction section (302) passes through the ring plate (201) and is fixed to the ring plate (201).
7. A pressure-retaining double-layer pipe according to claim 1, 2, or 3, characterized in that, The contact cylinder (501) is arranged vertically, with the inner end of the contact cylinder (501) being the upper end and the outer end of the contact cylinder (501) being the lower end. The transfer cylinder (502) is arranged vertically, with the inner end of the transfer cylinder (502) being the upper end and the outer end of the transfer cylinder (502) being the lower end. The lower end of the contact cylinder (501) is located below the bottom of the outer PE pipe (2), and the lower end of the transfer cylinder (502) is located below the bottom of the outer PE pipe (2). The double connecting pipe (506) is located below the bottom of the outer PE pipe (2).
8. A pressure-retaining double-layer pipe according to claim 7, characterized in that, It also includes an external support component, which includes a vertical mesh cylinder (701) and a pair of arc plates (702) that abut against the bottom of the outer PE pipe (2). The arc plates (702) are fixed to the top of the vertical mesh cylinder (701). The lower end of the contact cylinder (501) is located inside the vertical mesh cylinder (701). The lower end of the transfer cylinder (502) is located inside the vertical mesh cylinder (701). The double connecting pipe (506) is located inside the vertical mesh cylinder (701).
9. A pressure-retaining double-layer pipe according to claim 8, characterized in that, A pre-inflatable airbag is provided on the inner wall of the vertical mesh cylinder (701). An initiating inflatable airbag (704) that can be punctured by the push-out tip (503.1) is fixed inside the vertical mesh cylinder (701). The initiating inflatable airbag (704) is fixed to the inner wall of the vertical mesh cylinder (701). The initiating inflatable airbag (704) is connected to the pre-inflatable airbag. The volume of the pre-inflatable airbag is 10 to 30 times the volume of the initiating inflatable airbag (704). When the conductive piston rod hole (503) extends to the limit position: the outer end of the contact cylinder (501), the pre-inflatable airbag and the push-out tip (503.1) are arranged in sequence along the sliding direction of the contact piston (501.1). The distance between the pre-inflatable airbag and the conductive piston rod hole (503) is less than 3 cm.
10. A pressure-retaining double-layer pipe according to claim 1, 2, or 3, characterized in that, The transfer cylinder (502) is equipped with a pressure dividing cylinder (507). The pressure dividing cylinder (507) is equipped with a pressure dividing pipe that passes through the side wall of the contact cylinder (501) and is sealed and fixed to the side wall of the contact cylinder (501). One end of the pressure dividing pipe is connected to the pressure dividing cylinder (507), and the other end of the pressure dividing pipe is connected to the contact low pressure chamber (501b). The part of the pressure dividing pipe outside the contact cylinder (501) is located outside the outer PE pipe (2).