In this assembly a Line Bellows is tied with the Balancing Bellows having twice the Effective area.

Due to tie arrangement, when the line Bellows is getting compressed to compensate the Pipe Expansion, the balancing Bellows will extend the equal amount, thus the volume across the Expansion Joint is maintained, hence no pressure thrust load

Inline Pressure Balanced Expansion Joints are used in straight pipe between two anchors to compensate the axial pipe growth, at the same time not to transfer the pressure thrust load to anchors.

They can accommodate small amount of lateral movement also.