Correct option is A
The schedule number (Sch.) of a pipe is a standardized way of indicating the wall thickness of the pipe. It is widely used in piping systems in industries such as oil and gas, power plants, and chemical processing. The concept originates from standards like ASME and ANSI, where pipes are classified based on their ability to withstand pressure.
As the schedule number increases (e.g., Sch 10, Sch 40, Sch 80), the wall thickness of the pipe also increases, which means the pipe can handle higher internal pressure. Importantly, for a given nominal pipe size (NPS), the outer diameter remains constant, while the inner diameter decreases as wall thickness increases.
