Grundfos offers a complete range of stainless-steel flow sleeves for both vertical and horizontal operation. We recommend flow sleeves for all applications in which motor cooling is insufficient. The result is a general extension of motor life. Flow sleeves are to be fitted in these cases:
• If the submersible pump is exposed to a high thermal load such as current unbalance, dry running, overload, high ambient temperature, and bad cooling conditions.
• If aggressive liquids are pumped, since corrosion is doubled for every 10 °C the temperature rises.
• If sedimentation or deposits occur around and/or on the motor.

See example
More information about flow sleeves and product numbers are available in SP accessories data booklet.


Example of calculated flow sleeve
The flow sleeve is fitted to the submersible motor so that the liquid passes close by the motor on its way towards the pump suction interconnector, thus ensuring optimum cooling of the motor. See fig. Flow sleeve function.


The flow sleeve is designed so that the flow velocity past the motor is minimum 0.5 m/s and maximum 3 m/s to ensure optimum pump operating conditions. Use this formula to calculate the flow velocity: