In-line pumps are pumps whose discharge and suction nozzle are in a straight line with the piping system. They are frequently used in building engineering. In building engineering, they are primarily used in heating technology as a circulating pump, but also in ventilation and air-conditioning technology.
In-line pumps are typically designed with a thread, flange, or weld connection. Correspondingly, these types are also referred to as screw-connected pumps, flange-type pumps, and weld-in pumps.
In principle, all in-line pumps are centrifugal pumps. Since they operate in buildings inconspicuously and have low maintenance requirements, the use of a pump with high-efficient motor can be practical. This can save a significant amount of energy compared to obsolete technology.