Orifice Plate Bevelling

Your question is not very clear, more is clarity less are assumptions.

But still

May be your system is calibrated for 1/8" of thickness and you need to bevel additional thickness of plate to nullify its effect on your system.

HI

I don't think that it's an orifice plate, it is nozzel which can be used to make pressure drop, beveled nozzel with 45° to reduce resistance against the flow.

The flow pattern resulting from the sharp edge produces pure line contact between the plate and effective flow , with negligable fluid to metal friction drag at this boundary.

Any burrs or rounding of the sharp edge can result in large errors.

For more info refer ISO 5167 Part 02

Regards

Jose John

This comes out of AGA3 and ISO5167.

I would assume it is linked to the flowprofile. With a bevel, you may reduce the chances to create vortex downstream of the plate, which would generate DP mysmeasurement

Hi there,

Simply put - the orifice plate causes an increase in flow velocity and a corresponding decrease in pressure. The flow pattern shows an effective decrease in cross section beyond the orifice plate, with a maximum velocity and minimum pressure at the vena contracta. This location may be from 0.35 to 0.85 pipe diameters downstream from the orifice plate, depending on β ratio and Reynolds number. This flow pattern and the sharp leading edge of the orifice plate that produces it are of major importance.

The sharp edge results in an almost pure line contact between the plate and the effective flow, with negligible fluid-to-metal friction drag at this boundry.

As you can see from above the beveling angle has to do with the flow pattern profile. Simply put - it gives you a greater margin to play with when placing your pressure taps.

Regards,

Craig

Hi there,

I found something even simpler for you:

This is the standard fl ow element "FE" type orifice plate. The orifice is

beveled on the downstream edge, in accordance to AGA report #3.

The purpose of the bevel is to reduce the width of the throat to the "e"

dimension. The ratio of the orifice bore divided by the line I.D. is called

the beta ratio"β". The "β" ratio should be between .2 and .7. The accuracy

of the flow coefficient diminishes beyond these limits.

Regards,

Craig

Beveling is required to make the orifice as close to an ideal sharp edged orifice as possible so the equations are valid. The ideal orifice has 0 thickness. Since that is not possible it has been found that a 1/16" sharp edge closely approximates the ideal.