Understanding Your Pool Plumbing System
Your pool's plumbing system is the backbone of everything — it moves water from the pool to your equipment and back, controls flow direction, and allows you to isolate components for service or winterization. The main categories of pool plumbing components are valves, fittings, and unions. Each plays a specific role, and knowing what you have and what you need makes repairs and upgrades significantly easier.
Valves are the most commonly replaced plumbing components in any pool system. Ball valves provide simple on/off flow control for equipment lines. Diverter valves split or redirect flow between two or more lines. Check valves prevent backflow, protecting equipment from reverse pressure. Filter valves (also called multiport valves) direct water through the different operating modes of a sand or DE filter. Most residential pool plumbing runs on 1.5 inch or 2 inch PVC, and the majority of valves and fittings are available in both sizes.
Fittings and unions round out the system. Unions allow equipment and valves to be disconnected and removed without cutting pipe, which is critical for servicing pumps, heaters, and filters. Couplings, elbows, and tees handle the structural connections throughout the plumbing run. Flow meters help you monitor and balance circulation across multiple returns or features.