Calculating Burst Pressure of Tubing
Calculating Burst Pressure of Tubing
(OP)
What is the equation for calculating Burst Pressure of a 1/2" I.D. x 5/8" O.D. x 2.40" long piece of LEXAN, polycarbonate tubing? It is open on both ends. The yield strength is 9000 psi and the ultimate tensile strength is 10,000 psi. Room temp water is flowing thru it.





RE: Calculating Burst Pressure of Tubing
P = 0.875 [2 Sy / (D/t)]
for P=internal pressure, Sy=yield stress, D=pipe OD and t=wall thickness.
I prefer the Von Mises-Hencky Equation for a triaxial state of stress.
S = sqrt(3) P [R^2/(R^2 - 1)] for R=D/d
D=OD and d=ID. You can substitute material yield strength for S and solve for internal pipe pressure given the OD and ID geometry. This model I have found to be extremely accurate and representative of practical, everyday engineering problems.
There are other models, you can use them for cross reference on your calculation. Good luck.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: Calculating Burst Pressure of Tubing
RE: Calculating Burst Pressure of Tubing
The square root of three is simply a scaling factor which drops out of the mathematics as a result of hoop, radial and longitudinal stresses of the thick wall pressure vessel theory.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada
RE: Calculating Burst Pressure of Tubing
B31.3 has a section for non-metallic piping. I would suggest that you give this code a look. I do not use nonmetallic piping in my industry but if it applies to your application, it can save you a lot of liability exposure.
Chris Foley
Midland, TX
RE: Calculating Burst Pressure of Tubing
Ken Shumway