Total pressure drop is the sum of major losses (straight pipe friction) and minor losses (valves, fittings, and changes in geometry). 2. Pipe Line Sizing Methodology
Hydraulic analysis determines how fluids behave inside a piping network. Accurate hydraulic calculations ensure that pumps, valves, and process equipment operate within their design limits. Fluid Flow Regimes
Verify the Reynolds number to confirm the fluid is within predictable turbulent limits.
Piping engineers typically size lines based on two primary constraints: and Allowable pressure drop . 1. Velocity Constraints Total pressure drop is the sum of major
Valves, elbows, tees, and reducers create localized turbulence, resulting in minor pressure losses. These are accounted for using two primary methods: Equivalent Length Method ( Leqcap L sub e q end-sub
What specific are you moving (e.g., water, hydrocarbons, steam)? What is your design flow rate or operating pressure ?
0.1% to 1% of the upstream absolute pressure per 100 meters. Step-by-Step Pipe Sizing Procedure 1. Velocity Constraints Valves
Use industry standards or company criteria to establish upper and lower limits.
Re=ρvDμcap R e equals the fraction with numerator rho v cap D and denominator mu end-fraction : Fluid density ( : Fluid velocity ( : Inside diameter of the pipe ( : Dynamic viscosity ( Laminar Flow (
A high-quality "Module 3 Process Piping Hydraulics Sizing and Pressure Rating" PDF should cover: and reducers create localized turbulence
The core formula for pressure design thickness (t) from ASME B31.3, Paragraph 304.1.2, is:
: Typical liquid velocities range from 1 to 3 m/s, while gas/steam velocities can reach 50–75 m/s depending on noise and erosion constraints. Preliminary Selection
Determine mass/volumetric flow rate, operating temperature, fluid density, and viscosity.