Summary:

A nuclear power company purchased several new service water VS6 pumps for their power plant.  As for all new nuclear installations, it needed to be shown that these pumps could withstand  static and dynamics loadings without structural failure.  The pump manufacturer requested Pythagoras Engineering to perform a three-dimensional finite element analysis to evaluate the response of the pumps to the structural loads. 

Scope:

The analysis focused on evaluating the stress of a casing when operating under full pressure with various specified nozzle loads.

Methodology:

To determine the structural integrity of the casing design under internal pressure and nozzle loads, a detailed finite element analysis was conducted with the model the discharge head, column shaft, motor casing, lines-haft, enclosure tube, baseplate, impellers, motor, and pedestal foundation are modelled.  Higher order elements are used for meshing the component. Bonded connections and frictional connections are considered between interfaces as per the behavior of the contact. The peak von-Mises stress of the assembly, and the peak stress locations, were determined and compared to stress criteria as per API 610,clause 6.3.4. Based on the analysis results, PE recommended that the pump casing design was structurally adequate to meet the operating pressure condition combined, with the specified nozzle loads.