Water Pressure Flow Rate Calculator

Flow Rate Formulas:

\[ V = \sqrt{\frac{2 \times (P_1 - P_2) \times 144}{\rho}} \] \[ Q = V \times A \times 448.83 \]

Initial Pressure (P₁):

psi

Final Pressure (P₂):

psi

Water Density (ρ):

lb/ft³

Cross-Sectional Area (A):

ft²

Velocity (V): ft/s

Flow Rate (Q): GPM

Definition: This calculator determines water flow rate (GPM) based on pressure difference, water density, and pipe cross-sectional area.

Purpose: It helps engineers, plumbers, and irrigation specialists design and analyze water systems.

The calculator uses these formulas:

\[ V = \sqrt{\frac{2 \times (P_1 - P_2) \times 144}{\rho}} \] \[ Q = V \times A \times 448.83 \]

Where:

Explanation: The pressure difference drives water flow, with velocity calculated from Bernoulli's principle, then converted to flow rate.

Details: Accurate flow rate estimation ensures proper system design, adequate water supply, and efficient pipe sizing.

Tips: Enter pressure values (P₁ > P₂), water density (default 62.4 lb/ft³), and pipe area. All values must be > 0.

Q1: What's the 144 factor in the formula?
A: It converts psi (lb/in²) to lb/ft² (1 ft² = 144 in²).

Q2: Why 448.83 in the flow rate formula?
A: This converts ft³/s to GPM (1 ft³/s = 448.83 GPM).

Q3: When would water density change?
A: Density varies slightly with temperature (62.3 lb/ft³ at 70°F, 62.1 at 100°F).

Q4: How do I find pipe cross-sectional area?
A: For circular pipes: \( A = \pi \times (diameter/2)^2 \), with diameter in feet.

Q5: Does this account for friction losses?
A: No, this is theoretical maximum flow. Real systems have lower flow due to pipe friction.