Approximate flow through an orifice
Orifice  equation adapted by E. Van de Putte
do: orifice diameter (mm).
Q : flow through the orifice (m3/h).		 h : head across the orifice (mwk).
db:  pipe diameter (mm).		 K: orifice shape (see drawing)
 
Equation Orifice popular shapes
equation Orifice shapes
Calculation (Use dot for decimals)
dia db mm. flow Q m3/h head h mwk.
K   Orifice do =   mm.