The objective of this paper is to identify one of the reasons for the crack to initiate at the tongue region. The design of the tongue region of the centrifugal pump casing plays an important role in influencing the pump performance and cavitation. Tongue region should have enough strength to withstand against repeated loads imparted by the impeller. Crack at the tongue region is examined under hydrostatic pressure conditions .Practically, at the site location it was observed that the crack was formed at the tongue region when the casing was tested under hydrostatic pressure. Static linear analysis is performed to identify the critical zone where the maximum stress occurs that causes failure. Maximum stress is observed at the tongue region. To reduce the maximum stress, ribs thickness was increased in addition to increasing the portion of the volute thickness. Geometrical modifications are suggested in such a way that there is no effect on the hydraulic performance and to avoid increase in manufacturing cost. Stress distribution of the centrifugal pump casing volute is simulated using finite element software like Ansys. In this paper an attempt was made to validate finite element analysis results with test conditions and found good concurrence between FEA results and theoretical results.
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