1. What is the CFM at PSI Formula?

The CFM (Cubic Feet per Minute) at PSI formula calculates the volumetric flow rate of gas through an orifice or vent based on pressure difference, area, and gas properties. It's commonly used in pneumatic systems and gas flow applications.

2. How Does the Calculator Work?

The calculator uses the CFM at PSI formula:

Where:

• \( C \) — Flow coefficient (dimensionless)
• \( A \) — Cross-sectional area (ft²)
• \( \Delta P \) — Pressure difference (PSI)
• \( SG \) — Specific gravity of gas (relative to air)

Explanation: The equation shows that flow rate increases with larger area and higher pressure differential, but decreases with heavier gases (higher specific gravity).

3. Importance of CFM Calculation

Details: Accurate CFM calculation is essential for designing pneumatic systems, sizing pipes and valves, and ensuring proper gas flow in industrial applications.

4. Using the Calculator

Tips: Enter the flow coefficient, area in square feet, pressure difference in PSI, and specific gravity of the gas. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical flow coefficient (C) value?
A: For sharp-edged orifices, C is typically 0.6-0.65. For well-rounded inlets, it can approach 1.0.

Q2: How does temperature affect the calculation?
A: Temperature affects gas density, which is accounted for in the specific gravity value at given conditions.

Q3: Can this be used for compressed air systems?
A: Yes, for air use SG=1.0. The formula works well for most compressed gas applications.

Q4: What are typical CFM requirements?
A: Small tools may need 2-5 CFM, while industrial applications can require hundreds of CFM at pressure.

Q5: How accurate is this calculation?
A: It provides a good estimate but actual flow may vary due to factors like turbulence, viscosity, and exact orifice geometry.