Certified Maintenance and Reliability Technician (CMRT) Practice Test

In a centrifugal pump, the conversion of the liquid's velocity into pressure occurs primarily in the volute. The volute is a spiral-shaped casing that surrounds the impeller, and its design allows it to gradually decrease the velocity of the liquid coming from the impeller. As the fluid travels through the expanding cross-sectional area of the volute, its speed decreases, which in turn increases the pressure according to Bernoulli's principle.

This process is essential for the pump's operation, as it transforms the kinetic energy imparted by the impeller into pressure energy, enabling the liquid to be transported efficiently through the discharge pipe. The careful design of the volute ensures that the pressure rises smoothly, minimizing turbulence and energy losses, which is crucial for maintaining the pump's performance.

While the impeller generates the velocity of the liquid, it is the volute that facilitates the conversion to pressure. The diffuser, which may also function in some pump designs to further enhance pressure recovery, works alongside the volute. The inlet pipe, on the other hand, simply directs the incoming fluid into the pump and does not play a direct role in converting velocity to pressure.