The reasons for the short service life of non-metallic expansion joints can be attributed to several aspects.

First, the quality and choice of materials have an important impact on the service life of non-metallic expansion joints. High-quality materials can provide better durability and stability, which can extend the life of the expansion joint. For example, the use of high-strength, corrosion-resistant materials can enhance the fatigue resistance of the expansion joint, making it stable during frequent expansion and contraction. On the contrary, if the material is of poor quality or improperly selected, it may lead to problems such as fatigue, aging and even breakage of the expansion joint during use, thus shortening its service life.

Secondly, design factors are also the key factors affecting the service life of non-metallic expansion joints. Reasonable design should take into account factors such as thermal expansion coefficient, pressure and displacement of the expansion joint, so as to ensure that the expansion joint will not be subjected to excessive stress or deformation during use. If the design is not reasonable, it may cause the expansion joint to bear excessive stress under certain working conditions, which may lead to failure or damage.

Furthermore, operation and maintenance during installation can also affect the service life of non-metallic expansion joints. For example, if the screw is not tightened properly during installation, it may cause the screw to loosen, causing the accumulated acid water to penetrate the screw and corrode, thus seriously affecting the service life of the expansion joint. At the same time, during operation, if the screw is loose or the tie rod is broken due to vibration and other reasons, the expansion joint may also be damaged. Therefore, during installation and use, the operating procedures should be strictly followed, and inspection and maintenance should be carried out regularly.

Finally, environmental factors and frequency of use can also have an impact on the service life of non-metallic expansion joints. For example, too high an ambient temperature may accelerate the softening and aging rate of the expansion joint, while too low an ambient temperature may cause the expansion joint to harden and crack. In addition, frequent use can also accelerate the fatigue and aging process of the expansion joint. Therefore, when using non-metallic expansion joints, attention should be paid to controlling the ambient temperature and frequency of use, and regular maintenance and maintenance should be carried out.

In summary, there are many reasons for the short service life of non-metallic expansion joints, including factors such as material, design, installation, use, and environment. In order to improve the service life of non-metallic expansion joints, it is necessary to start from many aspects and take comprehensive measures to improve and optimize.