What is the term for the production of mounds of rust on the inside of a pipe?

The term for the production of mounds of rust on the inside of a pipe is tuberculation. Tuberculation occurs when localized corrosion leads to the formation of small, rounded deposits or 'tubercles' on the surface of the pipe. These deposits are typically composed of iron oxide and other corrosion products that can significantly impede the flow of water, reduce the effective diameter of the pipe, and create areas of stagnant water that can foster further corrosion.

Understanding tuberculation is important for water operators because it can affect the water quality and the efficiency of the water distribution system. The presence of these mounds can lead to increased maintenance needs and could indicate underlying issues with water chemistry or pipe material that ideally should be monitored and addressed.

The other terms refer to different corrosion processes; for example, corrosion itself is a broad term that encompasses the deterioration of materials due to chemical reactions, while pitting is a type of localized corrosion that results in small holes or 'pits' in the metal. Scaling refers to the buildup of mineral deposits, typically from hard water, that can coat the inside of pipes but does not involve rust. Thus, tuberculation specifically describes the formation of rust mounds, making it the most accurate term in this context