For a better experience, please enable JavaScript in your browser before proceeding.

A better approximation can be had by finding the minor loss coefficient for your orifice plate from the manufacturer.

Sources I can reference suggest that a well-drilled, clean and smooth orifice can be approximated with a discharge coefficient of 0.5 to 0.7, for example.

You can find the mass flow rate ( Qm ) via a restatement of the discharge coefficient equation: Qm Cd A sqrt2 rho Delta P.where.

Heres a link with a section on orifices with a little more help on discharge coefficients.

Im so old i grew up with pressure in poundalssquare foot, mass in pounds mass.

Rotation angle measurement of pedal with ball and socket joint.

Calculating the coldest outside temperature my campervan can be in and still be warm inside.

Nozzles and orifices are often used to deliberately reduce pressure, restrict flow or to measure flow rate.

Definitions: Diameter: Area: Discharge coefficient: Gravitational acceleration: Fluid head: Change in fluid head: Ratio of specific heats (.

The increase in velocity comes at the expense of fluid pressure resulting in low pressures in the Vena Contracta.

In extreme cases this may lead to cavitation when the local pressure is less than the vapour pressure of a liquid.

Downstream of the Vena Contracta in the recovery zone, the fluid decelerates converting excess kinetic energy into pressure as it slows.

When the fluid has decelerated and returned to the normal bulk flow pattern the final downstream pressure has been reached.

You can find typical values in our article on discharge coefficients for nozzles and orifices.

Calculations The relationships for flow rate, pressure loss and head loss through orifices and nozzles are presented in the subsequent section.

Horizontal Orifices and Nozzles For orifices and nozzles installed in horizontal pipework where it can be assumed that there is no elevation change, head loss and flow rate may be calculated as follows: Property Equation Flow rate (in terms of.

For incompressible fluids: American Gas Association method as described in AGA 3.1: International Standards Organistion method as described in ISO 5167-2: Further Reading Flow Measurement Engineering Handbook, R.

W. Miller Albrights Chemical Engineering Handbook, L.

Albright Instrument Engineers Handbook, Vol.

Process Measurement and Analysis Article Created: February 11, 2015 Article Tags Discharge Coefficient Expansion Coefficient Flow Orifice Nozzle Orifice Restriction Orifice Venturi Meter Subscribe to our mailing list Email Name 2020 Native Dynamics Contact Copyright and Disclaimer.

Flow Through Orifice Equation Pressure