Flow Rate of Water Through an Orifice

formula

\(p_1 - p_2 < FL^2 \cdot \left( p_1 - FF \cdot p_{av} \right) \rightarrow \)

\(Q_w = 0.0865 \cdot C_d  \cdot  \left(  \frac  {d_o} {4.654 } \right)^2  \cdot \sqrt { \frac { p_1 - p_2 } { SG }  }   \)

\(p_1 - p_2 \ge FL^2 \cdot \left( p_1 - FF \cdot p_{av} \right) \rightarrow \)

\(Q_w = 0.0865 \cdot C_d  \cdot  \left(  \frac  {d_o} {4.654 } \right)^2  \cdot  FL  \cdot \sqrt { \frac { p_1 - FF \cdot p_{av} } { SG }  } \)

Where:

\(Q_w\) = flow rate of water

\(p_1\) = primary pressure

\(p_2\) = secondary pressure

\(FL\) = pressure recovery factor (=0.9)

\(FF\) = critical pressure ratio factor

\(p_{av}\) = absolute vapor pressure of the water at inlet temperature

\(SG\) = specific gravity of water

\(C_d\) = discharge coefficient

\(d_o\) = diameter of orifice