Pressure Drop

Written by Matt Milbury. Posted in Pump

The difference in pressure between two points, usually caused by friction resistance in the pipe, but moisture can also affect it.

Formula

A relationship for turbulent flow in commercial steel pipes is:

\(\Delta P = \frac{Q^{1.8} \mu^{0.2}}{C \cdot d^{4.8} \cdot \rho}\)

Where:

\(\Delta P\) = pressure loss due to friction, psi per 100' of pipe

\(\mathrm{C}\) = 20,000 for rough carbon steel pipe and 23,000 for smooth tubes.

\(Q\) = flow rate, lb/hr

\(\mu\) (Greek symbol mu) = Viscosity, cp

\(\rho\) (Greek symbol rho) = density of the fluid, lb/ft3

\(d\) = the internal pipe diameter, In