Summary

Jacketed expansion joints consist of two bellows, one on the inside and one on the outside. In this design, inner bellows is pressurized internally and externally while the outer one is pressurized internally only.

Jacketed expansion joints are used where regular insulation is not sufficient to maintain the goal temperature and when the main fluid going through the bellows needs to be kept at a fixed temperature.

Fluid is circulated between two bellows via inlet and outlet connections attached on the outer pipe. Inlet and outlet connections are attached on opposite sides of the bellows apart from 180 degrees. This facilitates heat exchange throu thermal growth of pipe.