Orifice Flow Meter Calculator
Design orifice plate flow meters per ISO 5167 standard
Input Parameters
Water: 1000, Air (STP): 1.2
Water: 0.001, Air: 0.000018
Typical range: 0.2 - 0.75
ISO 5167 Formula
Q = Cd × Y × E × A × √(2ΔP/ρ)
• Cd = Discharge coefficient
• Y = Expansion factor
• E = Velocity approach factor
• A = Orifice area
Design Results
Orifice Diameter
50.0
mm
Differential Pressure
64.26
kPa
Flow Characteristics
Discharge Coefficient (Cd):0.6042
Reynolds Number:176,839
Expansion Factor (Y):1.000
Beta Ratio (β):0.500
Velocities & Pressure Loss
Pipe Velocity:1.77 m/s
Orifice Velocity:7.07 m/s
Permanent Pressure Loss:36.14 kPa
Loss Ratio:56.3%
Design Recommendations
- ✓ Reynolds number in fully turbulent range
- ✓ Beta ratio in optimal range (0.3-0.7)
Beta Ratio Guidelines
- • β = 0.2-0.4: High ΔP, high accuracy, high loss
- • β = 0.4-0.6: Balanced ΔP and loss
- • β = 0.6-0.75: Low ΔP, lower accuracy, low loss
Learn More
Understand the principles of orifice flow meters, ISO 5167 standards, discharge coefficient correlations, and pressure loss calculations.
View Theory & Examples