Pipes Schedules

Overview

Engineering reference data for Pipes Schedules in fluid mechanics.

Key Formulas

Reynolds Number

$Re = \frac{\rho v D}{\mu}$

Ratio of inertial to viscous forces — determines flow regime.

Bernoulli's Equation

$P + \frac{1}{2}\rho v^2 + \rho g h = \text{const}$

Conservation of energy for steady, inviscid, incompressible flow.

Continuity Equation

$A_1 v_1 = A_2 v_2$

Conservation of mass for incompressible flow.

Darcy-Weisbach

$\Delta P = f \frac{L}{D} \frac{\rho v^2}{2}$

Pressure drop due to friction in a pipe.

Variables

Symbol	Description	Unit
$Re$	Reynolds number	—
$\rho$	Fluid density	kg/m³
$v$	Flow velocity	m/s
$D$	Characteristic dimension	m
$\mu$	Dynamic viscosity	Pa·s
$P$	Pressure	Pa
$f$	Darcy friction factor	—

Pipe Schedule Terminology

The schedule of a pipe defines its wall thickness and pressure rating. Key designations include:

• Schedule (Sch.): A numerical identifier indicating wall thickness. For a given nominal pipe size (NPS), a higher schedule number means a thicker wall.
• Standard Wall (STD): For NPS 1/8 to NPS 10, STD is equivalent to Schedule 40. For NPS 12 and above, it may align with Schedule 30 or specific thicknesses.
• Extra Strong (XS): For NPS 1/8 to NPS 8, XS corresponds to Schedule 80. For NPS 8 to NPS 12, it is often Schedule 80, with variations for larger sizes.
• Double Extra Strong (XXS): A wall thickness approximately double that of XS pipes, not directly tied to a schedule number; it exceeds Schedule 160 for some sizes.

These terms standardize pipe dimensions for engineering design and specifications.

References

• Original Source