In addition to the most common repair technology of hose lining method, trenchless repair technology has the following several kinds:
The pipe rehabilitation technology of U-type lining HDPE pipe is also called the tight joint lining method. The principle is to use an HDPE pipe with an outer diameter slightly smaller than the inner diameter of the old pipe. The HDPE pipe is pressed into a U shape by a deforming device and temporarily bundled to reduce its diameter. Pass the HDPE pipe into the old pipe by the tractor, and then use the water pressure or gas (steam) pressure and the soft ball to open it and restore it into its original diameter, so that the HDPE pipe will expand and stick to the inner wall of the old pipe. The close cooperation forms a "pipe-in-pipe" composite structure in which the anti-corrosion performance of the HDPE pipe is combined with the mechanical performance of the original pipe. After the pipeline is repaired, due to the medium pressure in the pipe, the lining pipe will eventually cling to the inner wall of the original pipe.
This type of repair technology is generally suitable for straight circular pipes with less structural damage, and can be applied to various types of pipes with a pipe diameter ranging from 75 to 2000mm and a pipeline length of about 1000m. The technology has been widely used in water supply and drainage and other related pipe network repair due to its advantages of good sanitary performance, small loss of flow section, wide range of deformation and long-distance repair.
The short pipe lining method is to drag the short pipe into the old pipe while welding it on site, and finally fill the gap between the new and old pipe with grout. This repair method is usually used when the water flow is low.
The cost of this method is relatively low. However, due to the relatively large section loss after pipeline repair, it is gradually being replaced by new technology.
The pipe breaking (cracking) method is a pipeline renewal method which uses the pipe breaking (cracking) equipment to break or split the old pipeline from the inside, squeeze the old pipe debris into the surrounding soil to form a pipe hole, and pull the new pipe (the same diameter or larger diameter) synchronously.
This type of repair technology can be applied to the renewal of old pipes of ceramics, unreinforced concrete, asbestos cement, plastic or cast-iron pipes, and the applicable pipe diameter ranges from 75 to 2000 mm.
Spiral winding method repair technology mainly uses spiral winding method to continuously advance the strip profile through the pressing bayonet to form a new pipe inside the old pipe. The pipeline can be operated with water (below 30%).
The spiral winding method is widely used at present. The inner wall of the pipe repaired by this technology is smooth, the water carrying capacity is better than that of the concrete pipe before repair, and the material occupation area is small, which is suitable for long-distance pipeline repair.
The repair technology of stainless-steel lining is to insert thin-walled stainless steel pipe inside the old pipeline, or weld the stainless-steel plate in the form of rolling plate inside the pipe, so as to achieve the purpose of anti-leakage and corrosion as well as improve the pressure level of the original pipeline. Since the stainless-steel lining can prevent the corrosion of the inner wall of the pipeline, reduce the roughness of the inner wall of the pipeline, increase the water flow, make the pipeline after the lining safer, lighter, more economical and have longer service life, it can achieve the purpose of repair. Take using situation of old pipe repair at home and abroad as references, this technology has been widely used in sewage pipelines because of its strong adaptability, reliable quality, and water operation.