Barlow's Formula

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Barlow's formula, abbreviated as Ba, relates to burst pressure, the point just before or at when a pipe or tubing fails under pressure.

 

Barlow's formulas

\(\large{ p =  \frac{2 \; S \; t}{D} }\) 
\(\large{ p =  \frac{4 \; S \; t}{ D \;+\; 2 \; t } }\)
\(\large{ p =  \frac{2 \; S \; t}{ \left(D \;-\; 2 \; t \right) \; SF  }  }\)
\(\large{ p =  \frac{2 \; S \; t}{D \; SF} }\)

Where:

 Units English Metric
\(\large{ p }\) = pressure \(\large{\frac{lbf}{in^2}}\) \(\large{Pa}\)
\(\large{ S }\) = allowable stress \(\large{\frac{lbf}{in^2}}\) \(\large{Pa}\)
\(\large{ D }\) = outside diameter of pipe \(\large{in}\) \(\large{mm}\)
\(\large{ t }\) = pipe thickness \(\large{in}\) \(\large{mm}\)
\(\large{ SF }\) = safety factor (generally 1.5 - 10, 1 for bursting pressure) \(\large{ dimensionless }\)

 

P D Logo 1

Tags: Pressure Equations Pipe Sizing Equations Pipe Equations