About the application of bellows expansion joints in heating engineering

As a compensation element with good compensation performance and easy maintenance, bellows expansion joints have been more and more widely used in domestic and foreign heat supply networks. In China, since the mid-1980s, when centralized heating was adopted, bellows expansion joints have increasingly replaced the traditional "п"-shaped compensation and sleeve compensation, contributing to the modernization of urban construction.
With the increase in the use of years, bellows expansion joint failure occasionally occurs, although the proportion is very low, due to the direct relationship between the people's lives, has increasingly drawn the attention of the relevant parties. Therefore, it is necessary to conduct a detailed analysis of the amount of bellows expansion joints, the number of failed expansion joints, and the causes of expansion joint failure in the last decade or so, in order to have a clear understanding of the reliability of such compensation devices. In order to improve the reliability of bellows expansion joints, it is necessary to develop reasonable solutions to the problems that occur during the use of bellows expansion joints.
Compared with spherical compensators, bellows expansion joints do not have the problem of sealing performance decreasing with displacement cycles. As the bellows is a thin-walled flexible element, it works under high stress and is the weaker part of the pipe system, so the stability of the bellows expansion joint becomes a concern for the users.
The reliability of bellows expansion joints is guaranteed by design, manufacture, installation, operation and management, etc. The loss of control of any one link will lead to the reduction of the life of the expansion joint or even failure, even so, from the application practice of bellows expansion joints in heating projects in the past ten years, its reliability is still very high.