1. What is Flow Through an Orifice?

Definition: This calculator determines the volumetric flow rate of a fluid through an orifice based on the pressure difference and fluid properties.

Purpose: It helps engineers and technicians design and analyze fluid systems involving orifices, such as in pipelines, valves, and flow measurement devices.

2. How Does the Calculator Work?

The calculator uses the orifice flow equation:

Where:

• \( Q \) — Flow rate (gallons per minute, GPM)
• \( C_d \) — Discharge coefficient (dimensionless, typically 0.6-0.8)
• \( A \) — Cross-sectional area of orifice (square feet)
• \( \Delta P \) — Pressure difference across orifice (psi)
• \( \rho \) — Fluid density (pounds per cubic foot)
• 448.83 — Conversion factor to GPM

Explanation: The equation calculates flow based on Bernoulli's principle, accounting for energy losses through the discharge coefficient.

3. Importance of Orifice Flow Calculation

Details: Accurate flow calculations are essential for system design, flow measurement, process control, and equipment sizing in fluid systems.

4. Using the Calculator

Tips: Enter the discharge coefficient (default 0.62 for sharp-edged orifice), orifice area, pressure difference, and fluid density (default 62.4 lb/ft³ for water). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the discharge coefficient (C_d)?
A: It's a dimensionless factor that accounts for energy losses and flow contraction through the orifice. Typical values range from 0.6 to 0.8.

Q2: How do I determine orifice area?
A: For circular orifices, A = π × (diameter/2)². Convert to square feet (1 ft² = 144 in²).

Q3: What fluid densities should I use?
A: Water at 68°F is 62.4 lb/ft³. For other fluids: gasoline ~46, mercury ~849, air ~0.075 (at STP).

Q4: What's the 448.83 conversion factor?
A: This converts ft³/s to GPM (1 ft³/s = 448.83 GPM).

Q5: When is this equation not valid?
A: For compressible flows (gases at high ΔP), very viscous fluids, or when Reynolds number is very low.