The suction side refers to the side of a pump where it sucks or receives liquid or other medium from an external source before moving it through the pumping system and pumping it to the discharge side. The suction side is, therefore, the inlet area of the pump.
Usually, on the suction side of a pump, there are devices such as suction pipes, suction valves or filters that are used to guide the medium from its point of origin into the pump. These components enable the pump to draw the medium into the pump chamber. From there, it is then gripped by the pump vanes or other pump elements and transported towards the discharge side.