): A fluid's resistance to gradual deformation by shear or tensile stress. Vapor Pressure ( Pvcap P sub v
The friction factor depends solely on the Reynolds number:
Sudden velocity changes create severe pressure shockwaves. Recommended Velocity Guidelines Pump Suction Lines (Liquids): (Low velocity prevents pump cavitation) Pump Discharge Lines (Liquids): Steam Lines: Gas/Vapor Lines: Line Sizing Calculation Steps ): A fluid's resistance to gradual deformation by
): Flow fluctuates between laminar and turbulent characteristics. Turbulent Flow (
[ \Delta P = f \cdot \fracLD \cdot \frac\rho v^22 ] Where: Turbulent Flow ( [ \Delta P = f
Use industry standard tables to pick an acceptable velocity range for your specific fluid.
As fluid flows through a pipe, friction converts mechanical energy into thermal energy, resulting in a permanent drop in pressure. The Darcy-Weisbach Equation These are called "minor losses" but can constitute
Frictional losses occur not only in straight pipes but also due to disruptions caused by valves, tees, elbows, and expansions. These are called "minor losses" but can constitute a significant portion of total pressure drop. They are calculated using two primary methods:
depends on both the Reynolds number and the relative roughness (
Sizing a pipe is an optimization challenge. A pipe that is too small creates excessive pressure drop and high energy costs. A pipe that is too large unnecessarily increases material, installation, and support costs. Continuity Equation