A single expansion joints consists of a bellows and two end pipes (or two flanges) . It is designed to absorb axial movement by the use of bellows flexibility. End pipes (or Flanges) are designed to connect the expansion joint with pipe line and the fixed bolts are designed to restrict the movement of bellows during shipment.A single expansion joints are mainly used to absorb axial movement, such as that caused by thermal expansion or contraction of a pipeline, duct or vessel along the axis.