Submersible motor pumps are pumps powered by submersible motors; they are able – without a suction pipe – to draw in medium directly from their environment. The characteristic feature of these pumps is the ability to submerge both the motor and pump unit either partially or completely in the pumped medium. Submersible motor pumps are employed mostly as borehole or mine pumps – in mobile and stationary systems – for drainage or for groundwater maintenance purposes. A maintenance-free design and high reliability are essential for units of this type because they are inaccessible when in operation, which often means continuous service and having to cope with frequent periods of dry running. As a rule, submersible motor pumps are sealed by mechanical seals in tandem arrangement.

Jacket-cooled large-capacity submersible pump, one
of the biggest currently in production, fitted with single
mechanical seals in tandem arrangement