What are the common classes of working pressure in water mains?

The correct answer highlights the common classes of working pressure in water mains, which are critical for ensuring the system can handle the pressures necessary for efficient operation and delivering water reliably.

Water mains typically operate at certain pressure classifications to provide a stable supply while preventing issues like pipe failure or inadequate flow. The pressures listed in the chosen answer—100 psi, 150 psi, 200 psi, and 250 psi—are standard levels that correspond to various operational needs and design specifications in the water distribution system.

For water utility operations, a pressure rating of 100 psi is often considered a minimum for distribution systems, with higher pressures providing greater capacity to serve end users, especially in system design to accommodate peak demands and elevation changes. Thus, identifying these pressure classes is essential for water system planning, ensuring that there’s sufficient volume and pressure to meet consumer needs and maintain system integrity.

The other options reflect different ranges that may not align as closely with typical standards for water mains in many systems, thereby making them less relevant to common practices in the field. Understanding these standardized pressure classes assists operators and engineers in making informed decisions when planning, designing, and maintaining water distribution systems.