Analysis Of Nozzle Loads For Process Pumps

Abstract

Under extreme conditions, pumps may be required to withstand severe nozzle loads, which often exceed the API 610 specified values. To meet these requirements, pump mechanical behavior versus nozzle loads must be examined in detail. Others have discussed shaft end displacement of centerline mounted pumps under nozzle loads. However, the subject of stresses on the pedestal bolts and casing is a critical area that must also be analyzed. An in-depth study was made on the deformation and stress analysis of centerline mounted end suction pumps, whose stiffness were relatively low and were frequently required to withstand rather high nozzle loads. The nozzle load analysis consisted of deformation and stress measurements, combined with finite element calculation. The analysis resulted in a versatile empirical formula for end suction, centerline mounted pumps that can be used to estimate the shaft end displacement, pedestal bolt stress and casing stress for arbitrary nozzle loads. This allows the determination of whether or not specified nozzle loading conditions can be tolerated by a given pump and pump support design.