Vacuum Pipe Line Pressure Drop

Overview

Engineering reference data for Vacuum Pipe Line Pressure Drop 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	—

Specific Conditions and Unit Conversions

The reference diagram for vacuum pipeline pressure drop is generated under a specific set of baseline conditions. Understanding these parameters is essential for applying the data correctly.

Initial Reference Conditions:

• Initial Vacuum Pressure: 20 in Hg gauge (equivalent to 67% vacuum).
• Pipe Specification: Steel pipes, Schedule 40.

Key Unit Conversions: Pressure drop and flow rate are often presented in different unit systems. The relationships are:

$1 \text{ in Hg} = 3.37 \text{ kPa}$ $1 \text{ scfm} = 0.472 \text{ nl/s}$

These conversions allow for translation between data presented in Imperial units (scfm, in Hg) and metric units (nl/s, kPa).

References

• Original Source