This Standard covers motor-driven centrifugal pumps of vertical shaft, single stage design with suction and discharge nozzles in-line. It includes dimensional interchangeability requirements and certain design features to facilitate installation and maintenance. It is the intent of this Standard that pumps of the same standard dimension designation, from all sources of supply, shall be interchangeable with respect to mounting dimensions and size and location of suction and discharge nozzles (see Table 1).