API 610 Centrifugal Pump Overhung type OH1 vs OH2

API 610 Centrifugal Pump Overhung type OH1 vs OH2 OH means “Overhung” In which the rotor is supported in the form of a cantilever Pump type OH1: Foot-mounted, single-stage overhung pumps shall be designated pump type OH1. Pump type OH2: Centreline-mounted, single-stage overhung pumps shall be designated pump type OH2. They have a single bearing housing to absorb all forces imposed upon the pump shaft and maintain rotor position during operation. The pumps are mounted on a base-plate and are flexibly coupled to their drivers.