Orifice Pipe Flow Calculation

Flow Rate Formula:

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

Discharge Coefficient (C_d):

Orifice Area (A):

ft²

Pressure Difference (ΔP):

psi

Fluid Density (ρ):

lb/ft³

Flow Rate (Q):

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1. What is Orifice Pipe Flow Calculation?

Definition: This calculator estimates the flow rate through an orifice in a pipe system using the orifice equation.

Purpose: It helps engineers and technicians determine the volumetric flow rate of fluids through restriction orifices in piping systems.

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, GPM)
\( C_d \) — Discharge coefficient (dimensionless, typically 0.6-0.65)
\( A \) — Cross-sectional area of orifice (square feet)
\( \Delta P \) — Pressure drop across orifice (psi)
\( \rho \) — Fluid density (pounds per cubic foot)
448.83 — Conversion factor to GPM

Explanation: The equation calculates flow based on the pressure difference created by the orifice restriction and the fluid properties.

3. Importance of Orifice Flow Calculation

Details: Accurate flow measurement is essential for system design, process control, and equipment sizing in piping systems.

4. Using the Calculator

Tips: Enter the discharge coefficient (default 0.62), orifice area in ft², pressure difference in psi, and fluid density in lb/ft³ (default 62.4 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 0.65 for sharp-edged orifices.

Q2: How do I calculate orifice area?
A: For circular orifices, use \( A = \pi \times (d/2)^2 \) where d is diameter in feet.

Q3: What's a typical fluid density for water?
A: Water at 60°F has a density of 62.4 lb/ft³. For other fluids, consult material property tables.

Q4: What pressure difference should I use?
A: Measure the pressure upstream and downstream of the orifice. ΔP is the difference between these two values.

Q5: Does this work for gases?
A: This simplified form works best for incompressible fluids (liquids). For gases, additional factors like compressibility must be considered.