Below is a detailed technical report based on industry standards (ASME B31.3, Darcy-Weisbach, pressure class ratings).
Size a carbon steel pipe for water flow Q = 150 m³/h (≈660 gpm), length 500 m, allowable ΔP = 250 kPa, T = 80°C.
= Weld joint strength reduction factor (mostly used for high temperatures)
Complete Guide to Process Piping Hydraulics: Sizing and Pressure Rating Below is a detailed technical report based on
In the absence of rigorous economic optimization, process plants utilize conservative allowable pressure drop limits per unit length:
Where:
For process plants, many engineers follow the "rule of thumb": (~2–4 psi per 100 ft) for liquids. Chaotic, mixed flow
Chaotic, mixed flow. Most process piping operates here. 2.3 Pressure Drop Calculations
Then select the nearest (Sch 10, 40, 80, etc.) such that the nominal wall thickness ≥ calculated.
Using the Hazen-Williams equation, we can calculate the required pipe diameter: Using the Hazen-Williams equation, we can calculate the
: Excessive pressure drop increases pumping costs and energy consumption. For non-compressible fluids, maintaining fully turbulent flow is essential to prevent stagnant areas.
) must account for manufacturing tolerances and environmental degradation:
). It is determined using the or calculated visually via a Moody Diagram .