This calculator and associated equations will determine the working pressure of a known diameter pipe. The equation used is Barlows Formula which relates the internal pressure of a pipe to the dimensions and strength of its material.

This formula applies to the design of autoclaves and other pressure vessels. The formula is named after Peter Barlow, an English mathematician.

Equation:

Where:

P = Fluid Pressure (psi)
T = Pipe Wall Thickness (in)
O.D. = Pipe Outside Diameter (in)
SF = Safety factor (General Calculations 1.5 10, Use 1 For Bursting Pressure)

S = Material Strength (psi) Ultimate Tensile strength or Yield strength can be used.
Ultimate should be used to determine the bursting pressure.
Yield can be used for estimating pressures at which permanent deformation begins.