PSI to GPM Formula

Flow Rate Formula:

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

Inlet Pressure (P₁):

psi

Outlet Pressure (P₂):

psi

Fluid Density (ρ):

lb/ft³

Pipe Diameter:

inches

Velocity (V): ft/s

Flow Rate (Q): GPM

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1. What is PSI to GPM Conversion?

Definition: This calculator converts pressure difference (PSI) to flow rate (GPM) through a pipe of specified diameter.

Purpose: It helps engineers and technicians determine fluid flow rates in piping systems based on pressure measurements.

2. How Does the Calculator Work?

The calculator uses Bernoulli's principle with these formulas:

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

Where:

\( V \) — Velocity (ft/s)
\( P_1 \) — Inlet pressure (psi)
\( P_2 \) — Outlet pressure (psi)
\( \rho \) — Fluid density (lb/ft³)
\( Q \) — Flow rate (GPM)
\( A \) — Pipe cross-sectional area (ft²)

Explanation: The pressure difference is converted to velocity, which is then multiplied by pipe area to get volumetric flow rate.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate estimation ensures proper system design, pump sizing, and process control in fluid systems.

4. Using the Calculator

Tips: Enter the pressure difference (P₁ - P₂), fluid density (default 62.4 lb/ft³ for water), and pipe diameter in inches. All values must be > 0.

5. Frequently Asked Questions (FAQ)

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

Q2: What's the 448.83 conversion factor?
A: Converts ft³/s to GPM (1 ft³/s = 448.83 GPM).

Q3: What density should I use for other fluids?
A: Use 49.2 lb/ft³ for gasoline, 78.6 lb/ft³ for seawater, or look up specific values.

Q4: Does this account for friction losses?
A: No, this is ideal flow. For real systems, consider additional pressure drop calculations.

Q5: What pipe sizes does this work for?
A: The formula works for any diameter, but turbulent flow assumptions may not hold for very small pipes.