Module 3 Process Piping Hydraulics Sizing And Pressure Rating Pdf

). Liquid boils, forming vapor bubbles that violently collapse when moving into higher pressure zones, pitting the metal. NPSH Available ( NPSHAcap N cap P cap S cap H sub cap A

The Reynolds number is a dimensionless quantity used to predict flow patterns.

To prevent erosion, noise, water hammer, and excessive pressure drops, designers use industry-standard velocity thresholds: Fluid Type Recommended Velocity Range (m/s) Recommended Velocity Range (ft/s) 1.5 – 3.0 Pump Suction Lines 0.6 – 1.2 Pump Discharge Lines 1.5 – 2.5 Steam (Saturated) 30.0 – 40.0 100 – 130 Steam (Superheated) 40.0 – 60.0 130 – 200 Gases / Vapors (General) 15.0 – 30.0 50 – 100 3. Hydraulics and Pressure Drop Calculations

The driving force for fluid movement is the pressure differential. The total pressure drop in a piping system is the sum of: To prevent erosion, noise, water hammer, and excessive

Compare with allowable ΔP. Adjust diameter if needed.

( Q = A \cdot v ) → ( d = \sqrt\frac4Q\pi v )

This module focuses on the engineering principles required to determine the optimal pipe diameter and verify its mechanical integrity under pressure. It bridges the gap between process requirements (flow) and mechanical design (safety) CEDengineering.com 1. Process Piping Hydraulics Adjust diameter if needed

The lowest rated component in the line (pipe, flange, valve) sets the system pressure rating.

(available in ASME B36.10)

A piping system is only as strong as its weakest component. While pipe is fabricated, flanges are cast/forged components with pre-defined ratings. To prevent erosion

tn=t+c1−Tolt sub n equals the fraction with numerator t plus c and denominator 1 minus cap T o l end-fraction = (typically for carbon steel) Tolcap T o l

If you reduce the pipe diameter, velocity increases. Higher velocity increases friction and erosion.