Journeyman Plumber Practice Exam

As the velocity of water increases, the pressure within a flowing fluid decreases. This phenomenon is illustrated by Bernoulli's principle, which states that within a flowing fluid, an increase in velocity leads to a decrease in pressure.

In practical terms, when water flows through a pipe and the velocity increases—due to a reduction in the pipe diameter, for example—the kinetic energy of the fluid increases. Since the total energy in a streamline flow must remain constant, the increase in kinetic energy results in a corresponding decrease in pressure energy.

This principle has various applications in plumbing and fluid dynamics, including the design of pipe systems where changes in diameter can affect both the flow rate and pressure within the system. Understanding this relationship is crucial for plumbers to ensure that systems operate efficiently and effectively, avoiding issues such as low pressure downstream or excessive flow speeds that may cause noise or wear on the piping material.