Which design enables isolating sections for repair and for contaminant containment, while allowing future expansion?

• A. Tree (Trunk) System
• B. Ring System
• C. Grid-Loop System
• D. Branch System

Answer: (C)

A grid-loop design uses interconnected loops throughout the network, with valves placed at strategic junctions. This topology lets you segment the system into isolated sections by closing boundary valves, so you can repair or sample a portion without shutting down the entire supply. If a contaminant is detected, you can quickly contain it by isolating the affected loop or zone, preventing spread to the rest of the network while keeping other areas supplied from neighboring loops.

Expansion is straightforward because new pipelines can be added by tying them into existing loops or by creating new loops within the grid, preserving redundancy and flow paths without reconfiguring a single trunk line. This combination of sectional isolation for repair and containment, plus easy growth, is what makes the grid-loop approach the best fit.