Orifice Flow Calculation Formula

Orifice Flow Formula:

\[ Q = C_d \times A \times \sqrt{\frac{2 \times \Delta P}{\rho}} \times 448.83 \]

Discharge Coefficient (C_d):

Area (A):

ft²

Pressure Difference (ΔP):

psi

Density (ρ):

lb/ft³

Flow Rate (Q): GPM

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1. What is Orifice Flow Calculation?

Definition: This calculator estimates the volumetric flow rate through an orifice based on the orifice characteristics and fluid properties.

Purpose: It helps engineers and technicians determine fluid flow rates in piping systems, hydraulic systems, and process equipment.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Q = C_d \times A \times \sqrt{\frac{2 \times \Delta P}{\rho}} \times 448.83 \]

Where:

\( Q \) — Flow rate (gallons per minute)
\( C_d \) — Discharge coefficient (dimensionless)
\( A \) — Cross-sectional area of orifice (square feet)
\( \Delta P \) — Pressure difference across orifice (psi)
\( \rho \) — Fluid density (pounds per cubic foot)

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

3. Importance of Orifice Flow Calculation

Details: Accurate flow measurement is critical for system design, process control, and equipment sizing in various industries including oil & gas, water treatment, and chemical processing.

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 a typical discharge coefficient value?
A: For sharp-edged orifices, 0.62 is common. Values range from 0.6-0.9 depending on orifice type and Reynolds number.

Q2: How do I calculate orifice area?
A: Area = π × (diameter/2)². Convert to square feet (1 ft² = 144 in²).

Q3: What units does this calculator use?
A: US customary units: psi for pressure, lb/ft³ for density, ft² for area, resulting in GPM flow rate.

Q4: Can I use this for gases?
A: This formula works best for incompressible fluids (liquids). For gases, additional compressibility factors are needed.

Q5: What affects the discharge coefficient?
A: Orifice geometry, edge sharpness, Reynolds number, and the ratio of orifice to pipe diameter.