When renewing sections of pipe in a hydraulic system, the nominal pipe size of the piping always indicates the __________.

Correct Answer: Option D — size for threaded connections

Nominal Pipe Size (NPS) is a standardized designation system for piping, not an actual measurement of the inside or outside diameter. It serves as a reference for thread compatibility and fitting connections. For hydraulic systems, engineers must consult wall thickness schedules to determine actual pressure ratings and flow capacities.