Pressure Loss across orifice plates

[brettstaines]

Can anyone tell me a simple formula which can be used to calculate the size of a a sharp edged orifice required to produce a given pressure drop for flow of water in a pipe?

 

[Shmulik]

Please try the following:

http://www.efunda.com/formulae/smc_fluids/calc_orifice_flowmeter.cfm

I hope this helps.