A pipeline doesn't just carry water — it fights against real, sometimes violent forces every time a valve closes, a pump starts, or a bend redirects flow, and it sits buried in soil that is quietly working to corrode it from the moment it's installed. At the Class 3 level, you move from operating individual pipes and valves to thinking about the distribution system as an engineered network: how it's designed to survive those forces, how isolation valves are planned so a single break doesn't take down half the city, how metallic pipe is protected from the ground it's buried in, and how a main is properly brought back into service after a repair.
Pipe Design Considerations
Pressure Class and Working vs. Test Pressure
Every pipe is manufactured to a specific pressure class (or, for PVC, a dimension ratio that determines its pressure rating) — the maximum working pressure i