Module 3 Process Piping Hydraulics Sizing And Pressure Rating Pdf Exclusive May 2026

Module 3: Process Piping Hydraulics Sizing and Pressure Rating PDF Exclusive Review

• P = Internal pressure (psi)
• S = Allowable stress (from ASME B31.3, dependent on temperature)
• t = Wall thickness (after corrosion allowance)
• OD = Outside diameter

t equals the fraction with numerator cap P cross cap D and denominator 2 open paren cap S cross cap E cross cap W plus cap P cross cap Y close paren end-fraction : Internal Design Pressure. : Outside Diameter of the pipe. : Allowable stress for the material at design temperature. : Quality factor (seamless vs. welded). Module 3: Process Piping Hydraulics Sizing and Pressure

Pressure Rating of Process Piping

Verdict: Worth every penny for process and piping engineers. P = Internal pressure (psi) S = Allowable

The Barlow’s Formula

The starting point for pressure rating is Barlow’s Formula: t equals the fraction with numerator cap P

2. Water Hammer

Sizing is not static. It involves transient analysis. If a valve closes too fast (ESD scenario), the kinetic energy of the moving fluid converts to pressure energy instantly. The Joukowsky equation estimates this surge: $$ \Delta P_surge = \rho \cdot a \cdot \Delta v $$ Where $a$ is the speed of sound in the fluid. This surge pressure must be added to the Design Pressure to ensure the pipe does not burst during an emergency stop.