Underground pipeline systems form a hidden network of urban infrastructure, undertaking the crucial functions of transporting water and gas and discharging sewage. Traditional excavation-based repair methods often require damaging the road surface, causing significant disruption to urban traffic and the surface environment. The emergence of trenchless pipeline repair technology provides an alternative for maintaining this underground network, and the repair equipment is the physical basis for realizing this technology.
Understanding the entire repair process begins with pipeline internal inspection and assessment equipment. This equipment mainly includes closed-circuit television (CCTV) inspection systems and pipeline periscopes. These systems use cameras to enter the pipeline and transmit real-time images to the ground control unit, accurately identifying defects such as cracks, misalignments, corrosion, or root intrusion, and their specific locations, providing a basis for subsequent repair decisions.
After inspection, the pipeline interior needs pretreatment, and appropriate cleaning equipment is then deployed. High-pressure water jet cleaning devices are common tools; they use high-energy water jets to flush the pipe walls, removing silt, scale, and other deposits. For harder blockages, milling robots are sometimes used. These robots, equipped with a rotating cutting head at the front, can break up and remove hard obstacles such as concrete slurry or tree roots that have invaded the pipe, creating a clean and well-defined working surface for the repair work.
The core of the repair work involves various in-situ curing and non-in-situ replacement devices. In-situ curing commonly uses ultraviolet (UV) curing equipment. This equipment pulls a resin-impregnated fiberglass tube into the pipe to be repaired, then uses a built-in UV lamp holder to expand it and press it tightly against the inner wall of the old pipe. UV light irradiation causes the resin to rapidly polymerize, forming a high-strength inner liner. Another common technique is the short-pipe lining method, where pre-manufactured high-density polyethylene (HDPE) pipe sections are mechanically pushed into the old pipe section by section and heat-fused at the ends to form a continuous new pipe.
For localized damage, point-filling repair devices come into play. These devices typically include an inflatable repair airbag or bushing device. During operation, a resin-coated bushing is positioned at the damage point, and then expanded using air or water pressure, forcing the resin to adhere tightly to the damage area. Once the resin cures, a localized patch is formed. This technique is highly targeted and suitable for repairing leaks at joints or small cracks.
The implementation of trenchless technology relies heavily on auxiliary and power equipment. The construction site requires generators to provide electricity, air compressors to provide pneumatic power, and winches and pulling devices to drag hoses or pipes. Remote control systems and construction monitoring instruments coordinate the operation of each equipment unit and monitor key parameters such as pressure, temperature, and speed during the repair process to ensure precise execution of the process.
The application scope of this technology is constrained by both equipment capabilities and geological conditions. The pipe diameter the equipment can handle, the innovative length of the repair section, and the degree of pipe curvature it can accommodate all have clearly defined technical parameters. Site conditions such as groundwater level, surrounding soil properties, and the distribution of other adjacent pipelines also directly affect the feasibility of equipment selection and construction plans.
Compared to traditional excavation, the use of trenchless repair equipment brings about many objective changes. It reduces excavation and construction waste, minimizing disruption to public transportation. Noise and dust levels are also typically lower. From a long-term operational perspective, the newly formed lining or pipeline can effectively extend the service life of the original pipeline system.
Technological advancements in equipment are accompanied by improvements in materials and automation. Improvements in resin material performance enhance the durability and chemical resistance of the cured lining. The automation and intelligence of equipment operation are gradually increasing, for example, through sensor integration for automatic adjustment of process parameters and real-time assessment of repair quality.
1. Trenchless pipeline repair relies on a series of specialized equipment. The process begins with internal condition exploration and assessment, followed by cleaning and preparation, and finally completion through processes such as curing, lining, or spot repair.
2. The specific application of equipment is constrained by both its own technical parameters and site environmental conditions, requiring targeted selection and adaptation based on the type of pipeline defect, pipe diameter, burial depth, and surrounding soil conditions.
3. The application of this technology and its equipment mainly has the objective effect of reducing direct interference with the surface environment, controlling the associated impacts of construction, and extending the service life of pipeline infrastructure.
