What is the definition of galvanized iron pipe?

Galvanized iron pipe refers to a type of piping that has undergone a specific protective process to enhance its longevity and resistance to corrosion. In this case, the correct answer highlights that galvanized iron pipe is dipped in zinc. This zinc coating serves as a sacrificial barrier, preventing rust and corrosion from affecting the underlying iron or steel. The process of galvanization not only extends the lifespan of the pipe but also makes it suitable for various applications, particularly in plumbing and piping systems.

The other choices describe different types of pipe coatings or materials that do not relate to the standard definition of galvanized iron pipe. For instance, lead coating poses health risks and is not a protective method used today, rubber linings apply to specific flexible piping needs not related to iron, and pipes made from recycled materials refer to a different aspect of sustainability in manufacturing rather than the protective process associated with galvanization.