API 685 Canned Motor Pump
The type OHC pump is driven by a canned motor and is characterized by a compact, integrated unit. The motor and pump form a unit with the rotor and the impeller fitted onto a common shaft.

The rotor is guided by two identical, medium-lubricated slide bearings. The stator of the drive motor is separated from the rotor using a cylindrical can. The rotor compartment itself, along with the hydraulic section of the pump, creates a combined compartment which is filled with pumping medium during operation. The heat loss from the motor is carried off by a partial flow between the motor and the stator. At the same time, the partial flow lubricates both slide bearings in the rotor compartment. The can, which is a hermetically sealed component, and the motor casing offer primary and secondary containment, respectively. Aside from the short, compact design and the very low noise level, this is what differentiates the canned motor pump from the magnetically coupled pump. The canned motor pump is the safest way to transport hazardous, toxic, and radio-active fluids. It is characterized by zero leakage operation without the need for monitoring instrumentation as well as maintenance friendly handling. More over, this pump can be operated under extreme conditions, i.e. temperatures from -120° C up to +425° C or operating pressure up to 1,200 bar.

Performance Ranges