What are typical design velocities for pipe sizing?

Design velocities balance pressure drop (energy cost) against pipe cost (capital). Typical ranges: liquids in suction lines 0.5-1.5 m/s (to ensure adequate NPSH), liquids in discharge 1.5-3 m/s, gravity drain lines 0.5-1 m/s, gases at low pressure 10-20 m/s, gases at high pressure 15-30 m/s, and steam 20-40 m/s. Erosion limits apply for solids-laden streams or corrosive fluids. Economic velocity analysis may optimize for specific applications.