Module 3: Process Piping Hydraulics Sizing And Pressure Rating Pdf Better

Process fluids often corrode metal. An extra thickness (e.g., 3mm) is added to the calculated $t$ to account for material loss over the plant's lifespan. $$t_required = t_calculated + \textCorrosion Allowance$$

Once the minimum required thickness is calculated, the next step is to select a commercially available pipe from standard "schedules" (e.g., Schedule 40, Schedule 80). The pipe's nominal wall thickness must equal or exceed t_min . These standard thicknesses are directly linked to a pipe's pressure rating at a given temperature.

): The pressure at which a liquid turns into a vapor. This is critical for avoiding cavitation in liquid systems. Flow Regimes Process fluids often corrode metal

From ASME B31.3, Eq. (3a): [ t = \fracP \cdot D2(SEW + PY) ] Where:

Piping components (flanges, valves, fittings) are rated based on ASME B16.5. These ratings define the max allowable pressure at a specific temperature (e.g., Class 150, 300, 600). As temperature increases, the allowable pressure decreases. 5. Summary and Key Takeaways The pipe's nominal wall thickness must equal or exceed t_min

tn=t+c1−Tolt sub n equals the fraction with numerator t plus c and denominator 1 minus cap T o l end-fraction

Before sizing a pipe, one must understand the behavior of the fluid moving through it. This is critical for avoiding cavitation in liquid systems

: Pressure drops from valves and fittings are accounted for using the K-factor method or the Equivalent Length method .

Re=ρvDμcap R e equals the fraction with numerator rho v cap D and denominator mu end-fraction Laminar Flow (