Final answer:
The claim that cast iron is the most frequently used material for piping is false, as modern piping materials are varied, with PVC, copper, steel, and ductile iron being common.
Step-by-step explanation:
The statement that cast iron is the most frequently used material for piping is false. While cast iron was a common choice for piping in the past, especially during the 19th and early 20th centuries, today's piping materials are more varied and include PVC, copper, steel, and ductile iron, among others. These materials provide different benefits in terms of strength, durability, cost, and suitability for various applications. Cast iron is still used in certain situations, such as for some municipal and industrial water supply systems, but it is no longer the predominant material for piping.