SIDDHARTH INDUSTRIES Vadodara, Gujarat

This is the simplest assembly in family of expansion joint. It consists of a bellow element with end connections. It is used for axial movement only in pipe configurations. However, it can also absorb small amounts of other two types of basic movements viz. lateral and angular Rotation. The expansion joint should not be expected to control the movement of the pipe. If the piping analysis shows that the expansion joint must accept axial compression, then the piping must be guided and constrained so that only that movement will occur. This expansion joint will not resist any deflections with any force other than the resistance of the bellows, which is a function of the spring rate times the deflection amount. It is incapable of resisting the pressure thrust along its axis, which is the product of the pressure times the effective, or cross sectional, area of the bellows.

Universal expansion joints contain two bellows with multiple convolutions joined by a center pipe or spool. These joints, also known as double or tandem bellows expansion joints are used for the purpose of absorbing any combination of axial, lateral, or angular movements in a piping system. When lateral movements are too excessive for a single axial expansion joint to accommodate or when there is a limitation on the amount of lateral forces allowed on the connecting piping or equipment, universal expansion joints are installed to accommodate these movements. Universal types can be supplied with or without tie rods. Tie rods connect the ends of the unit to each other and restrain the pressure thrust load. This unit is normally not expected to accept any externally applied axial deflections. The tie rods usually come in sets of two or more, equally distributed around the circumference of the expansion joint.