En13480 hoop stress appears to incorrect per code equation in AutoPIPE,
The AutoPipe program reports incorrect hoop stress results for the European piping code EN13480. AutoPipe shows the pipe as failing code requirements, when hand calculations prove that it passes per code. The problem is how AutoPipe calculates the hoop stress formula, which is derived from the Euro code formula 6.1-1.
From AutoPIPE help:
It looks like the program is only calculating the first term of the above equation (Pmax)(D0)/2ez and neglecting the second term (Pmax)(Y)/z.For my example:
AutoPIPE Properties and Results:
The hoop stress result should be 52.1 MPa but AutoPipe reports 60.8 MPa, which is the result of the first term only.
Please verify and comment
AutoPIPE is working correctly.
Note the value of eh = reduced pipe wall thickness (eh = en - c0 - c1), therefore the correct wall thickness in the equation should be
Eh = 24.2 - 3.025 = 21.175 mm
Rendering the equation to:
En13480 Piping calculations