A submersible pump (or electric submersible pump (ESP)) it has a hermetically sealed motor close-coupled to the pump body. The whole assembly is submerged in the fluid to be pumped. The main advantage of this type of pump is that it prevents pump cavitation, a problem associated with a high elevation difference between pump and the fluid surface. Submersible pumps push fluid to the surface as opposed to jet pumps having to pull fluids. Submersibles are more efficient than jet pumps. They do not need primimg and are working well in areas where freezing becomes a problem.

Immage Example: Section through Grundfos SQFlex - As standard, all Grundfos SQFlex models are made entirely of stainless steel DIN W.-Nr. 1.4301 (AISI 304). 

MAX HEAD : A bigger value it is obtained with Helical Rotor type of pumps (up to 800ft)

MAX FLOW: A bigger value it is obtained with Centrifugal type of pumps (up to 80gl/min)

Dry-Running protection: This unique feature shuts down the pump if it detects water shortage. Every SQFlex pump comes standard with this sensor pre-installed, protecting the well from being over-pumped and the pump from damage.

Motor protection: Built in protections against over-temperature, overload, and over and under-voltage for reliability, as well as two-way communication with a control box to alert you in case there’s a problem.

Any voltage: The motor can operate under any voltage from 30 - 300 VDC and 90 - 240 VAC without additional controls, making sizing and installation easy, even as a retrofit to existing installations. AC power capabilities mean every SQFlex pump has the ability to use an AC generator for backup power.