V纶 cable pipes with polished inner surfaces and coated interiors have been improved through the optimization of material composition and production processes. This enhancement increases the smoothness of the inner wall, reducing frictional resistance to less than 0.3, significantly lower than other types of cable pipes. This allows for an extended cable pull length of up to 100-130 meters, minimizing the need for manholes and lowering construction costs as well as the physical strain on workers. Inner polishing involves using high-speed polishing equipment to create a dense, smooth surface on the hard inner wall of the pipe. Inner coating is achieved by uniformly applying a layer of graphite emulsion lubricant to the inner wall of the pipe using a coating machine. For these reasons, this technology is widely used in underground cable projects internationally.