Restriction Orifice Thickness Calculation/Formula and source Standard
Restriction Orifice Thickness Calculation/Formula and source Standard
(OP)
Hi, I want to know the formula to calculate Restriction Orifice Thickness, I found on the internet this one "Minimum RO thickness ≥ SQRT [(0,681-0,651*Beta)*deltaP/Y] * pipeID" it says it is according to R.W. Miller, but I could not find it in the Flow Measurement Handbook Miller 3rd Edition.
Can anybody help me with this matter? Which is the formula and the source (book and chapter or a Standard)?
Thanks.
Can anybody help me with this matter? Which is the formula and the source (book and chapter or a Standard)?
Thanks.





RE: Restriction Orifice Thickness Calculation/Formula and source Standard
This Miller refers to the calculation methodologies of Roark as contained in his timeless "Formulas for Stress and Strain"
http://rwmillerengr.com/fcfiles/FAQ.htm
(Miller, of course is selling his own software)
http://www.madinstro.net/tech/opthick.html
Many of the postings on the net refer to something called "ASME 3-31-3 Calculation orifice thickness"
This specific topic has been discussed before on these hallowed fora:
MJCronin
Sr. Process Engineer
RE: Restriction Orifice Thickness Calculation/Formula and source Standard
I hope I can find or somebody answers this issue clearly.
RE: Restriction Orifice Thickness Calculation/Formula and source Standard
You've already received a quite straightforward answer from MJCronin, which seems anyway to elude you.
From plates theory: σmax = 6Mmax/t^2
where:
σmax =max stress
Mmax = max bending moment
t = plate thickness
Moreover σmax ≤ Y
where:
Y = yield strength of the material the plate is made off
From "Roark’s Formulas for Stress and Strain" sec. 11-14 you can find the formula to compute Mmax
Then work out for t (definitely boring) and the game is done.