Module 3: Process Piping Hydraulics, Sizing, and Pressure Rating Introduction to Process Piping Design
Valves, tees, elbows, and reducers disrupt fluid flow, causing additional pressure drops known as minor losses. These are quantified using the resistance coefficient (
Verify fluid properties (density, viscosity, vapor pressure) at operating and design temperatures. Check Reynolds number to confirm the fluid flow regime.
Components like flanges and valves are selected based on established Pressure-Temperature (P-T) Ratings rather than individual thickness calculations. ASME Digital Collection Process Piping Fundamentals, Codes and Standards Module 3: Process Piping Hydraulics, Sizing, and Pressure
The allowable pressure drop is typically dictated by the available "energy budget" of the pump or compressor. In most process plants, a rule of thumb is a pressure drop of 1–2 psi per 100 feet of pipe. 3. Pressure Rating and Wall Thickness
The hydraulic design of a piping system is the first major pillar covered in Module 3. Pipeline hydraulics deals with the flow and transportation of fluids in pipes, and it is the process engineer's primary tool for pipe sizing.
Application of the Continuity equation, Bernoulli's equation, and basic fluid flow equations to determine pipe sizing and recommended velocities for various mediums like water and steam. Hydraulic Calculations: Components like flanges and valves are selected based
A high-quality "Module 3 Process Piping Hydraulics Sizing and Pressure Rating" PDF should cover:
Q = A₁ × v₁ = A₂ × v₂
) : Fluid mixes chaotically. Typical for most industrial water, gas, and steam applications. Calculating Friction Losses Application of the Continuity equation
: Wall thickness coefficient (varies by material class and temperature range) Mechanical and Environmental Allowances The nominal thickness ( tnomt sub n o m end-sub
This is the "Sizing and Rating" loop. The pipe is sized for flow (hydraulics), but the components are rated for thermal-mechanical survival (pressure rating).