Flexican bellows & hoses, an iso 9001-2000 company, is a leading manufacturer and exporter of a range of bellows, and the first in india to make bellows expansion joint. When axial deflections exist, and anchoring is impractical for structural or economic reasons, such as high in the air or short straight pipe runs between two large vessels, the flexican in-line pressure balanced expansion joint is a powerful solution to a difficult design problem. The principle of this type of unit is essentially the same as the pressure balanced bellows with elbow/tee section, in that the axial pressure thrust is reacted by the pressure acting on a cross-sectional area equal to the area of the working or primary bellows. Since this unit is entirely axial, and there are no directional changes in the pipe, the cross-sectional area needed to balance the pressure forces are generated by the pressure acting on the annular surface between the primary and outer, or balancing bellows, the arrangement of the tie rods transfers and balances the pressure thrust created in the pipe on each end. Now the forces needed to compress or extend the unit are only the result of the spring resistance of the bellows, and main anchoring of the pipe or vessels is not required. This expansion joint is obviously more expensive than the simpler types; however, they may result in a lower overall system cost when the elimination of main anchoring is considered.
