Grundfos' Inline Single Stage

Grundfos’ inline single-stage range highlights the TP/TPE series which are robust and reliable vertical centrifugal pumps with a mechanical shaft seal. A key feature is a close-coupled design, which means the pump and motor are separate units – making them less sensitive to impurities in the pumped liquid compared to canned rotor pumps. A non-return flap valve in the common outlet port prevents backflow of the pumped liquid. The specially constructed shaft seal chamber is key to optimised water circulation and a prolonged shaft seal life.

In-line pumps are centrifugal type pumps, and flow of fluid does not change inside the inline pumps. Before the single-stage centrifugal pump is started, the pump casing is filled with the liquid to be transported for priming. The impeller is then driven by the shaft to rotate at a high speed, and the liquid between the blades must also rotate. Under the action of centrifugal force, the liquid is thrown from the center of the impeller to the outer edge of the vanes and obtains energy. Liquid leaves the impeller with high speed and enters the volute casing. Here, the liquid decelerates due to the gradual expansion of the flow path, and part of the kinetic energy is converted into static pressure energy. Liquid then flows into the discharge pipe at a relatively high pressure.