Orifice Plate Flow
Orifice Plate Flow
(OP)
How do you calculate the flow through an orifice plate? They want to replace an existing orifice plate with one that has a smaller bore size. How can I calculate what the flow through the new plate is going to be?





RE: Orifice Plate Flow
Q1/Q2 = d1^2/d2^3
you can rerange the d/p measurement though it is sqrt(h1)/sqrt(h2) ...
lots of parameters are ignored, so this is a just a plant calculation for what its worth...
RE: Orifice Plate Flow
I have the following information for the existing plate:
Fluid: Air
Specific Gravity: 1.0
Viscosity: 0.0192 cPS
K (CP/CV): 1.41
Barometer: 14.7 PSIA
Base Conditions:
Temperature: 60.0 Deg. F
Pressure: 14.73 PSIA
Compressibility: 0.9991
Flowing Conditions:
Temperature: 110.0 Deg. F
Pressure: 26.7 PSIA
Compressibility: 0.9993
Line Size: 6.0"
Differential Range: 0-20"H2O
My new orifice plate is 316SST, 150# flange rating, 6.0", Bore Size: 1.3543
What is the expected flow through this plate?
RE: Orifice Plate Flow
They have a lot of useful info there.
Dan
www.eltronresearch.com
Dan's Blog
RE: Orifice Plate Flow
http://www70.de.abb.com/fpd500/gui/index.html
RE: Orifice Plate Flow
Although I have a question about the data you posted. Suppose somebody here took it and came back with an answer "you need an orifice with an orifice of 1.15 inches." (This is a totally bogus number. Do NOT use it!!)
How would you justify using that value to your management? Do you really think saying "Someone on a free Internet site told me the answer" would work?
You'd be a lot better off asking "where can I find out how to calculate this myself. (and,by the way, do you have a copy of Crane's Technical Paper 410, "Flow of Fluids Through Valves, Fittings, and Pipes?")
Sorry, rant over.
Patricia Lougheed
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RE: Orifice Plate Flow
About the "info"... I posted it because I thought that someone who saw it might have the sizing program and be able to quickly pop out the flow I can expect to get. I already have an orifice plate, I just don't know what kind of flow I will get through it.
Unfortunately, I am not very familiar with orifice plates and do not have the software to help me.
RE: Orifice Plate Flow
RE: Orifice Plate Flow
Appologies for the delay, I come up with 135.5 scfm at the conditions you've provided for flange or close-up taps and a square-edged orifice plate.
RE: Orifice Plate Flow
I just downloaded the program that rikiraph2 suggested. I'm going to try to duplicate your answer on my own so that I will know how to do if myself next time.
Thanks again!!!