Balancing technique “ON SITE " is useful in open access rotors such as fans, rollers, spindles, rotors , Fixtures or in closed access clearing dishes pre - installed, as the case of vertical pumps, turbines, etc. The main advantage of balance “On Site “is the cost savings in the removal, transport, and assembly bench execution large rotors or weights, or installed in inaccessible locations requiring cranes or other hazardous operations. All rotating components experience significant quality and performance improvements if balanced. Balancing is the process of minimizing vibration, noise and bearing wear of rotating bodies. When unbalance has been identified and quantified, the correction is straightforward. Weight has to be either added or removed from the rotating element. The ultimate aim being to reduce the uneven mass distribution so that the centrifugal forces and hence the vibrations induced in the supporting structures are at an acceptable level.