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Benchmark Case | Experience Sharing on the Repair of Pipes of Varying Sizes Using UV Curing
UV curing repairIn UV curing repair, the fit between the hose liner and the original pipe wall is crucial to the quality of the repair. Currently, the industry commonly suffers from the problem of selecting liner sizes too broadly: using smaller hoses results in a smooth and aesthetically pleasing repair, but the liner may not fit snugly against the pipe wall, creating cavities; using larger hoses risks the accumulation of wrinkles on the pipe wall. If the pipeline has a variable diameter structure, the difficulty of matching the size increases exponentially, and most teams can only passively "make do" with one end, unable to meet the fitting requirements of both large and small pipe diameters.
This issue brings you...Xingmo TechnologyIn Hohhot, Inner Mongolia Autonomous Region, a successful UV-cured repair project was completed on a section of HDPE double-wall corrugated pipe with dual diameter variations (DN1000-700-1000). Based on precise pre-construction measurements of the entire pipeline, we customized an integrated gradient-lined flexible hose and implemented standardized diameter-changing construction and protection procedures, achieving a 95.6-meter section...steel casingThe composite pipe section was seamlessly and tightly lined throughout, achieving a good repair effect.
I. Project Background
The target of this repair was the HDPE double-wall corrugated pipe for the core sewage discharge in the factory area, with a total length of 95.6 meters. The pipeline structure was highly unique.
• Pipe diameter structure:
Complete formationDN1000→DN700→DN1000The pipeline features continuous bidirectional diameter changes, with large diameters at both ends and a narrowing diameter in the middle, resulting in two gradual tapering points.
•Sealed steel casing section:
The middle section of the pipeline includes a 36-meter-long, enclosed steel casing, which is narrow and has a high coefficient of friction on the pipe wall.
• Media environment:
Industrial wastewater pipelines carry silt and corrosive wastewater over long periods of time, placing stringent requirements on the fit, sealing, and corrosion resistance of the molded lining.
Conventional UV repair processes are mostly suitable for single-diameter, short-distance or single-change-diameter pipes. This project presents three major challenges: ultra-long distance, double-change-diameter, and long steel sleeve. Each of these challenges places extremely high demands on material performance, equipment control, and construction calculations.
III. Precautions
Material customization：SelectHigh modulus glass fiber substrateMatchingUV-curable resinSynchronous configurationThickened wear-resistant base filmandReinforced waterproof layerMultiple layers of protection resist scratches and wear caused by steel sleeves and diameter-changing protrusions;
Precision molding process:High-precision splicing process, customized gradient integrated hose, perfect size adaptation without deviation, matching the slope forming requirements of bidirectional variable diameter pipes.
ChangePipeline pretreatmentreason：Grind and smooth the sharp cement edges at the diameter change point, create a gentle transition slope, eliminate hard protrusions, and prevent the hose substrate from being scratched during dragging.
Precise alignment verification:After the hose and bottom membrane are pulled into the steel sleeve,Second underground verificationEnsure that the pre-shrinking section of the hose coincides with the pipe diameter change point;
Variable diameter reinforced buffer:A special variable diameter binding cloth is used to wrap the transition area to buffer the shrinkage stress of the pipe diameter and prevent the interface from bulging, bursting and delamination during inflation;
Graded voltage regulation and wrinkle control:Slow, uniform, and graded pressure application and holding, in real timeEndoscopic monitoringThe variable diameter design reduces dead folds and ensures smooth and uniform passage of the lighting vehicle.；
Full-area re-inspection before curing:A second endoscopy is performed before formal curing to check for wrinkles, cracks, etc. Only after passing the inspection can curing be started.
Molding endoscope re-inspection and acceptance:Curing completebackCCTV inspection robot goes down into the well for inspection.The lining in the two diameter transition areas is smooth and uniform in thickness.。
(After repair)
With the ongoing urban renewal and urban lifeline safety projects, a large number of industrial and municipal pipelines that have been in service for many years are gradually entering the renovation cycle. The successful implementation of this industrial wastewater treatment plant diameter reduction repair project has verified the adaptability of Xingmo Technology's UV-CIPP hoses under complex working conditions such as large diameter reduction, long distance, and mixed materials, and has provided a technical path that can be learned from for similar scenarios in the industry. This provides a non-drilling, minimally disturbing, and highly efficient solution for the repair of a large number of diameter reduction and irregularly shaped pipe sections in the old urban pipe network.
