Rubber Expansion joints or Rubber bellows are primarily used to absorb noise and thermal movements along with the removal of vibration between equipment such as diesel engines, cooling water pumps, condensers, chillers and their mating pipe work. Their high flexibility also makes them suitable for compensating small installation misalignments. Rubber bellows can be used just like a metal expansion joint to compensate for axial, lateral or angular movement. As with any other unrestrained expansion joint, rubber bellows will extend under pressure. Their pressure thrust varies with length as the shape of the bellows changes, however the forces involved are just as large and the pressure thrust should be calculated by multiplying the cross sectional area by the maximum pressure. To prevent the bellows from extending, Tie rods should be fitted or the pipe work needs to be anchored well.