Which component is not found in a centrifugal pump?

A centrifugal pump consists of various components that work together to move fluid. The volute is a spiral-shaped casing that collects the fluid expelled by the impeller, converting the kinetic energy of the fluid into pressure. The impeller is the crucial rotating component that imparts energy to the fluid, facilitating its movement through the pump. Vanes, which are attached to the impeller, help guide the fluid and enhance the efficiency of the impeller's action.

In contrast, a piston ring is a component typically associated with reciprocating pumps or internal combustion engines. It serves to seal the gap between the piston and the cylinder wall, preventing the escape of gas or liquid. Since centrifugal pumps operate differently, their design does not include piston rings, making this component not found in centrifugal pumps. Understanding the specific components associated with different types of pumps helps clarify their operational principles and design intentions.