What role do metal expansion joints play in heating pipes?

Heating pipes often encounter a problem, that is, thermal expansion and contraction. When the pipeline inside the hot water through the water pipe will expand, when there is no hot or cold water inside, the pipe will contract, the volume will become smaller, the installation of metal expansion joint is to solve this problem of thermal expansion and contraction.
Hot water flows through the stainless steel bellows in the expansion joint. According to the design requirements of the heating pipeline construction, when the water temperature in the pipeline reaches 70 degrees Celsius, the pipeline starts to expand due to the heat, the corrugated metal hose is compressed, and the pipeline elongates to reach the design length. In the water supply water temperature is greater than 70 degrees Celsius, the working state of the pipeline compensator is compressed, and the working state of the expansion joint is stable. When the heating and cooling is stopped, the working state of the corrugated compensator is under tension when the temperature is less than 70℃.
Installing a compensator can solve this problem. When the pipe is elongated, he will become shorter to absorb the stress generated when the pipe is expanded; when the pipe is shortened, the compensator will become longer to compensate for the shortened pipe. The compensator looks like a spring, and the compensator installed in the pipe will contract when the pipe is under tension, and the compensator will stretch if the stress of the pipe is felt, effectively protecting the pipe.
Spring is an elastic limit, if the spring is too straight, the spring may lose its role, the same compensator if not installed bracket to protect it, once the stretching reaches a certain limit, the whole compensator will lose its actual effectiveness.