Water Flow Rate Through a Valve
Water Flow Rate Through a Valve formula
| \(\large{ p_1 - p_2 < F_l^2 \left( p_1 - F_f \; p_{av} \right) \rightarrow }\) | |
| (Eq. 1) \(\large{ Q_w = C_v \; \sqrt { \frac{ p_1 \;-\; p_2 }{ SG } } }\) | |
| \(\large{ p_1 - p_2 \ge F_l^2 \left( p_1 - F_f \; p_{av} \right) \rightarrow }\) | |
| (Eq. 2) \(\large{ Q_w = C_v \; F_l \; \sqrt { \frac{ p_1 \;-\; F_f \; p_{av} }{ SG } } }\) |
Where:
| Units | 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 | \(\large{\frac{lbf}{in^2}}\) | \(\large{Pa}\) |
| \(\large{ p_2 }\) = secondary 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 | \(\large{dimensionless}\) | |
Tags: Equations for Flow Equations for Valves Equations for Water Equations for Valve Sizing