These are a common sight on many steam boilers. The purpose of these pigtails as they are called is simply to protect the gauge or pressure control from a drastic spike. The condensate that has settled in the belly of the loop serves as a buffer between the rising steam pressure and the sensitive bellows within the pressure control and allows for a gradual increase in pressure versus those hard spikes that can have irreversible damage.
Find out more at [ Ссылка ]
![](https://s2.save4k.ru/pic/CsP7xBtbATM/maxresdefault.jpg)