Recently, Germany has launched a new PP (polypropylene) sewer system. This type of pipeline has excellent stiffness, with a deformation rate of only 2.3% after one year underground, significantly lower than ordinary PP pipelines. According to the actual test results, the deformation rate of the modified PP sewer pipeline is as high as 8%, occupying an area of one year. This new type of pipeline adopts three-layer technology. The inner and outer layers of the pipeline are generally made of PP, and the middle layer of PP is a compound composed of PP and magnesium silicate. The cross-linking of compounds can improve the elasticity of materials. A modulus with high stiffness can withstand high loads for a long period of time. In addition, this three-layer PP sewer connection uses a rubber sealed snap ring. Even if external forces and loads cause 30% deformation, the connecting socket will not disconnect or detach.