What Does Barlow's Equation Mean?
Barlow's equation shows the relationship between a pipe's internal pressure, its allowable stress, the pipe's nominal thickness, and its diameter. Using three of these four variables enables you to calculate the fourth.
For instance, if you wish to know how thick a pipe's walls must be to withstand 12,000 p.s.i. and you know the allowable stress, the pipe's proposed diameter and the internal pressure of the materials passing through the pipe, you would use Barlow's equation to determine the pipe wall thickness.