1. What is the GPM Calculation?

The GPM (Gallons Per Minute) calculation estimates flow rate based on the flow coefficient (CV) and pressure (PSI). It's commonly used in fluid dynamics and engineering applications to determine liquid flow through valves and pipes.

2. How Does the Calculator Work?

The calculator uses the flow rate equation:

Where:

• \( GPM \) — Flow rate in gallons per minute
• \( CV \) — Flow coefficient (unitless)
• \( PSI \) — Pressure in pounds per square inch

Explanation: The equation shows that flow rate is proportional to the square root of the pressure differential across the valve or pipe.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate estimation is crucial for system design, valve sizing, and ensuring proper operation of fluid systems in various industries including water treatment, chemical processing, and HVAC.

4. Using the Calculator

Tips: Enter the flow coefficient (CV) and pressure (PSI). Both values must be positive numbers. The calculator will compute the flow rate in gallons per minute (GPM).

5. Frequently Asked Questions (FAQ)

Q1: What is the flow coefficient (CV)?
A: CV is a dimensionless number that represents the flow capacity of a valve at fully open conditions with 1 psi pressure drop.

Q2: What are typical CV values?
A: CV values vary by valve size and type. Small valves might have CV values under 1, while large valves can have CV values in the hundreds.

Q3: Does this equation work for all fluids?
A: This simplified version is primarily for water. For other fluids, viscosity and specific gravity corrections are needed.

Q4: What's the relationship between PSI and GPM?
A: Flow rate increases with the square root of pressure. Doubling the pressure increases flow by about 41% (√2 ≈ 1.41).

Q5: When is this calculation not accurate?
A: It may not be accurate for very high velocities, cavitating conditions, or when fluid properties differ significantly from water.