1. What is a GPM Calculator from PSI?

Definition: This calculator estimates flow rate in gallons per minute (GPM) based on pressure difference using Bernoulli's equation.

Purpose: It helps engineers, plumbers, and fluid system designers determine flow rates in pipes based on pressure measurements.

2. How Does the Calculator Work?

The calculator uses these formulas:

Where:

• \( V \) — Velocity (feet per second)
• \( P_1 \) — Initial pressure (psi)
• \( P_2 \) — Final pressure (psi)
• \( \rho \) — Fluid density (pounds per cubic foot)
• \( Q \) — Flow rate (gallons per minute)
• \( A \) — Pipe cross-sectional area (square feet)

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

3. Importance of Flow Rate Calculation

Details: Accurate flow rate estimation ensures proper system design, pump sizing, and performance evaluation 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 area. All values must be > 0 except P₂ 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) for consistent units.

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

Q3: When would I change the fluid density?
A: For fluids other than water (e.g., oil ρ≈55 lb/ft³, gasoline ρ≈42 lb/ft³).

Q4: How do I find pipe area?
A: For circular pipes: \( A = \pi \times (diameter/2)^2 \) (convert diameter to feet).

Q5: Does this account for friction losses?
A: No, this is ideal flow. For real systems, consider additional head loss calculations.