Water Flow Rate Through an Orifice Calculator

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 Drop (ΔP):

psi

Fluid Density (ρ):

lb/ft³

Flow Rate (Q): GPM

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is a Water Flow Rate Through an Orifice Calculator?

Definition: This calculator estimates the volumetric flow rate of water through an orifice based on the orifice characteristics and pressure conditions.

Purpose: It helps engineers, plumbers, and technicians determine the flow rate in gallons per minute (GPM) through an orifice plate or restriction.

2. How Does the Calculator Work?

The calculator uses the orifice flow equation:

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

Where:

\( Q \) — Flow rate (gallons per minute, GPM)
\( C_d \) — Discharge coefficient (dimensionless, typically 0.6-0.8)
\( A \) — Cross-sectional area of the orifice (square feet, ft²)
\( \Delta P \) — Pressure drop across the orifice (pounds per square inch, psi)
\( \rho \) — Fluid density (pounds per cubic foot, lb/ft³)
448.83 — Conversion factor from ft³/s to GPM

Explanation: The equation calculates flow rate based on the energy balance across the orifice, accounting for the discharge coefficient which represents the efficiency of the flow through the orifice.

3. Importance of Orifice Flow Calculation

Details: Accurate flow rate calculation is essential for proper system design, flow measurement, control valve sizing, and ensuring adequate water supply in plumbing and industrial systems.

4. Using the Calculator

Tips: Enter the discharge coefficient (default 0.62 for sharp-edged orifice), orifice area in square feet, pressure drop in psi, 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 0.6-0.8 depending on orifice geometry and edge conditions.

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

Q3: What affects the discharge coefficient?
A: Orifice shape, edge sharpness, thickness, and the Reynolds number of the flow.

Q4: Can I use this for other liquids besides water?
A: Yes, but you must input the correct density for your specific fluid.

Q5: Why is the conversion factor 448.83?
A: This converts cubic feet per second to gallons per minute (1 ft³/s = 448.83 GPM).