Collecting pump and load information is the first step in reviewing the pump loads. API 610 (10th Edition) examines pump loads at two levels:
Individual nozzle loads
Combined nozzle loads on the pump housing
The suction and discharge nozzles have a set of allowable load limits based on nozzle orientation and nozzle size. The software checks the individual X, Y, and Z components, the resultant forces, and the moments. Additionally, to assure maintenance of proper pump/motor alignment, the software resolves all loads on the pump about a base point and compares these loads to their allowable values.
An API-610 pump analysis using Equipment Analysis requires the nozzle suction and discharge sizes, positions, orientations, and loads. The processor provides the load limits. For this tutorial, the software has already calculated the discharge nozzle loads. Therefore, the software only checks the discharge nozzle and does not evaluate the suction limits or the resolution to the base point.
For an analysis of a production system, you typically want both suction and discharge loads.
Even though all loads are not known, you will provide the entire description of the pump for Equipment Analysis. The following graphic illustrates the orientation of this pump with its end suction nozzle and top discharge nozzle. Both nozzles are dimensioned back to the base point, which is the intersection of the shaft axis and the support line for the pump. The drive shaft centerline is along the local X-axis of the pump.
Refer to the static analysis output from Tutorial A to get the discharge nozzle loads. Because the discharge nozzle served as a boundary condition for this analysis, the restraint reports list the nozzle loads. The forces and moments on the restraint at node 5 represent the piping loads acting on the discharge nozzle. The operating loads and installation loads must both fall below the defined limits. Examination of the restraint summary for the operating and sustained (installed) cases reveals that the operating loads are the controlling case to use for the discharge nozzle analysis.