1. What is the Water PSI to GPM Formula?

The Water PSI to GPM formula calculates the flow rate of water through a valve or pipe based on pressure drop and flow coefficient. It's commonly used in hydraulic engineering, plumbing, and fluid dynamics to determine flow capacity.

2. How Does the Calculator Work?

The calculator uses the flow rate formula:

Where:

• \( Q \) — Flow rate (gallons per minute)
• \( C_v \) — Flow coefficient (valve capacity)
• \( \Delta P \) — Pressure drop across the valve (PSI)
• \( SG \) — Specific gravity of the fluid (water = 1.0)

Explanation: The formula shows that flow rate is proportional to the square root of the pressure drop, with the flow coefficient determining the valve's capacity.

3. Importance of Flow Rate Calculation

Details: Accurate flow rate calculation is essential for proper valve sizing, system design, pump selection, and ensuring adequate water supply for various applications.

4. Using the Calculator

Tips: Enter the flow coefficient (Cv) from valve specifications, pressure drop in PSI, and specific gravity (1.0 for water). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the flow coefficient (Cv)?
A: Cv is a valve's flow capacity - the flow rate in GPM of water at 60°F that will pass through the valve with a 1 PSI pressure drop.

Q2: How does specific gravity affect the calculation?
A: Higher specific gravity fluids (denser than water) will have lower flow rates at the same pressure drop due to increased resistance.

Q3: What is a typical Cv value for valves?
A: Cv values range from less than 1 for small valves to over 1000 for large industrial valves, depending on size and design.

Q4: Can this formula be used for gases?
A: This specific formula is designed for liquids. Gas flow calculations require different formulas accounting for compressibility.

Q5: What factors affect pressure drop in a system?
A: Pipe length, diameter, fittings, elevation changes, valve type, and fluid viscosity all contribute to pressure drop.