What does tuberculation refer to in a water pipe?

Tuberculation in a water pipe refers to the formation of small mounds or projections of corrosion products on the interior surface of the pipe. This phenomenon occurs predominantly in iron or steel pipes, where corrosion leads to the accumulation of rust and other materials that can impede water flow and potentially affect water quality. The presence of these tubercles can create uneven surfaces, which not only restrict the passage of water but can also provide ideal conditions for further corrosion and biofilm growth.

Understanding tuberculation is critical for utilities maintenance workers since it can lead to decreased water flow rates, increased energy costs for pumping, and a higher risk of pipe failure. Addressing tuberculation early can help maintain the efficiency and longevity of water infrastructure.

The other options describe different issues that do not accurately represent tuberculation. For instance, excessive pressure buildup, layering of different materials, and physical damage to the outer pipe each relate to distinct problems within water distribution systems.