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

This article is designed to serve as an educational resource and a guide for engineers, students, and technicians looking for structured content similar to what might be found in a technical training module.

• $t$ = Pressure design thickness.
• $P$ = Internal design pressure.
• $D$ = Outside diameter.
• $S$ = Allowable stress from material tables (depends on temperature).
• $E$ = Quality factor (longitudinal weld joint efficiency).
• $Y$ = Temperature coefficient.

2. Piping Hydraulics (Fluid Flow Fundamentals)

Hydraulics governs how fluid moves through the pipe. The primary goal is to calculate pressure drop ($\Delta P$) to ensure the fluid arrives at its destination at the required pressure. This article is designed to serve as an

Save this article, download the referenced standards, and practice with real problems—because theory becomes engineering only when applied. $t$ = Pressure design thickness

2.2 Pressure Drop ($\Delta P$)

The driving force for fluid movement is the pressure differential. The total pressure drop in a piping system is the sum of: acceptable velocities typically range from

2. Systematic Pipe Sizing Workflows

• Step-by-step sizing based on:

  ) is calculated using factors like internal design gage pressure ( ), outside diameter ( ), and allowable stress ( Corrosion Allowance : Designers must add extra thickness (often 1.5 mm to 3 mm

  A. The Economic Velocity

  • Small pipes result in high velocity $\rightarrow$ high pressure drop $\rightarrow$ high energy (pump) costs.
  • Large pipes result in low velocity $\rightarrow$ low pressure drop $\rightarrow$ high material and installation capital costs.
  • Goal: Find the diameter where the sum of Capital Expenditure (CAPEX) and Operating Expenditure (OPEX) is minimized.

  Velocity Limits: For normal liquid service, acceptable velocities typically range from