PSI to GPM Conversion

Flow Rate Formula:

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

Initial Pressure (P₁):

psi

Final Pressure (P₂):

psi

Fluid Density (ρ):

lb/ft³

Cross-Sectional Area (A):

ft²

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) using fluid dynamics principles.

Purpose: It helps engineers and technicians determine fluid flow rates through pipes and orifices based on pressure measurements.

2. How Does the Calculator Work?

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:

\( V \) — Velocity (ft/s)
\( P_1 \) — Initial pressure (psi)
\( P_2 \) — Final pressure (psi)
\( \rho \) — Fluid density (lb/ft³)
\( Q \) — Flow rate (GPM)
\( A \) — Cross-sectional area (ft²)

Explanation: The first formula calculates velocity from pressure difference, the second converts velocity to flow rate in gallons per minute.

3. Importance of PSI to GPM Conversion

Details: Accurate flow rate calculations are essential for designing piping systems, selecting pumps, and ensuring proper system operation.

4. Using the Calculator

Tips: Enter the pressure values (P₁ and P₂), fluid density (default 62.4 lb/ft³ for water), and cross-sectional area. All values must be > 0 (except P₂ which can be 0).

5. Frequently Asked Questions (FAQ)

Q1: Why multiply by 144 in the formula?
A: This converts psi (lb/in²) to lb/ft² (1 ft² = 144 in²).

Q2: What's the 448.83 conversion factor?
A: This 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 for your fluid.

Q4: How do I calculate cross-sectional area?
A: For circular pipes: \( A = \pi \times (diameter/2)^2 \).

Q5: Does this account for friction losses?
A: No, this is for ideal flow. For real-world applications, consider additional factors like pipe roughness and length.