Module 3 Process Piping Hydraulics Sizing And Pressure Rating Pdf

Choosing the correct pipe diameter requires balancing capital expenditure (the cost of pipes, valves, and installation) against operating expenditure (the energy costs for pumps or compressors). Velocity and Pressure Drop Guidelines

Before calculating diameters, you must understand how fluids behave within the pipe. Module 3 typically covers: The Continuity Equation

: Typical liquid velocities range from 3–8 feet per second (fps) . High velocities can cause erosion, noise, and excessive pressure drop, while low velocities may lead to sediment buildup.

The lowest rated component in the line (pipe, flange, valve) sets the system pressure rating. High velocities can cause erosion, noise, and excessive

For liquids, keep ΔP below 2 – 3 bar/100 m for economic pumping.

For pump suction piping, minimize pressure losses to ensure Net Positive Suction Head Available ( NPSHAcap N cap P cap S cap H cap A ) exceeds Net Positive Suction Head Required ( NPSHRcap N cap P cap S cap H cap R ) to prevent cavitation.

If you are saving this module for reference, you can output this layout directly to a printing tool from your browser to maintain a clean engineering reference document. For pump suction piping, minimize pressure losses to

tn=t+c1−Tolt sub n equals the fraction with numerator t plus c and denominator 1 minus cap T o l end-fraction

Where:

Understanding how fluids behave inside a pipe is the first step in accurate hydraulic sizing. Engineers categorize flow based on fluid properties and velocity. Flow Regimes: Laminar vs. Turbulent For pump suction piping

): Characterized by chaotic fluid particles and rapid mixing. Most industrial process piping operates deep within this regime. The Continuity Equation

Process piping hydraulics involves understanding the behavior of fluids (liquids, gases, or multiphase) moving through pipes. 1.1 Fluid Properties Density (

Once a standard pipe size is selected, you must verify that the pressure drop over the run is within acceptable limits. Darcy-Weisbach Equation The primary method for calculating frictional head loss ( ) in a pipe is:

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