Which statements describe considerations when sizing cold water pipes to meet fixture demand and control downstream pressure drop?

• A. Size to meet peak simultaneous demand, limit downstream pressure drop, and use hydraulic calculations or code tables.
• B. Size pipes only by total length, ignoring demand.
• C. Size to the smallest possible diameter to save material.
• D. Size based solely on fixture count, regardless of distribution.

Answer: (A)

Sizing cold water pipes is about planning for how much water will be needed at the same time and making sure pressure stays acceptable as water moves through the network. You can’t rely on total length or just counting fixtures, because a run with several outlets open together can require more flow than a small pipe can deliver. By sizing for peak simultaneous demand, you ensure there’s enough volume when multiple fixtures are used at once. Controlling downstream pressure drop is essential so that even the farthest outlets aren’t starved of pressure as water loses energy traveling through pipe and fittings. Using hydraulic calculations or code tables gives you a rational, repeatable method to select pipe diameters based on actual flow rates, lengths, and expected friction losses, rather than guessing. The other approaches don’t account for how flow distributes along the network or how pressure changes with distance and fittings, which can lead to undersized pipes and poor performance.