Water Flow Rate Through a Valve

on . Posted in Fluid Dynamics

Tags: Flow Water Valve Sizing 

 

Water Flow Rate Through a Valve formula

\(\large{ Q_w = C_v \; \sqrt { \frac{ p_1 \;-\; p_2 }{ SG }  }   }\)
Symbol English Metric
\(\large{ Q_w }\) = water flow rate \(\large{\frac{ft^3}{sec}}\) \(\large{\frac{m^3}{s}}\)
\(\large{ p_1 }\) = primary pressure \(\large{\frac{lbf}{in^2}}\) \(\large{Pa}\)
\(\large{ p_2 }\) = secondary pressure \(\large{\frac{lbf}{in^2}}\) \(\large{Pa}\)
\(\large{ C_v }\) = valve flow coefficient \(\large{dimensionless}\)
\(\large{ SG }\) = specific gravity of water \(\large{dimensionless}\)

 

Water Flow Rate Through a Valve formula

\(\large{ Q_w =  C_v \; F_l \;  \sqrt { \frac{ p_1 \;-\; F_f \; p_{av} }{ SG }  }   }\)
Symbol English Metric
\(\large{ Q_w }\) = water flow rate \(\large{\frac{ft^3}{sec}}\) \(\large{\frac{m^3}{s}}\)
\(\large{ p_{av} }\) = absolute vapor pressure of the water at inlet temperature \(\large{\frac{lbf}{in^2}}\) \(\large{\frac{kg}{m-s^2}}\)
\(\large{ F_f }\) = liquid critical pressure ratio factor \(\large{dimensionless}\)
\(\large{ p_1 }\) = primary pressure \(\large{\frac{lbf}{in^2}}\) \(\large{Pa}\)
\(\large{ F_l }\) = id pressure recovery factor (= 0.9) \(\large{dimensionless}\)
\(\large{ C_v }\) = valve flow coefficient \(\large{dimensionless}\)
\(\large{ SG }\) = specific gravity of water \(\large{dimensionless}\)

 

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Tags: Flow Water Valve Sizing