Orifice plate thickness & design dp

[hollerg]

What is the downside to taking a high pressure drop for a liquid flow meter orifice, so long as I ensure there would be no flashing, accept a small beta ratio, to avoid using a throttling valve? I imagine the orifice edge blunting is more rapid.

If I were to take 50 psi drop would it be best to switch to a square edge orifice? This is to monitor flow to a chiller +/- 3 %

Lastly what yield stress value should bs used in the miller equation. I would have thought proof stress values would be correct for annealed material, or the stress values from ASME, however examples I see are using 450 to 540 mpa rather than 220 mpa (ambient)

 

[BigInch]

If I recall, accuracy will suffer when the [β] ratio gets too small.

Square edge sounds questionable.

Throttling and measurement usually arn't compatible applications.

Failure is probably by excessive deformation, rather than exceeding yield stress.

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[JLSeagull]

The standard orifice plate thickness selections are suitable up to 1000 inches water differential. Thicker plates are suitable for pressure drop such as your 50 psi example. If dropping more than 500 psi then begin to consider a choke.