Calculate flow rates and discharge coefficients per ISO 5167 standards
Calculate flow rates with ISO 5167 compliance
Volumetric Flow Rate
-
m³/s
Mass Flow Rate
-
kg/s
Discharge Coefficient
-
Cd
-
d/D
-
Dimensionless
-
m/s
-
Status
The basic orifice meter equation calculates flow rate (Q) as:
Q = Cd × Ao × √(2ΔP/ρ)
where:
- Cd is the discharge coefficient
- Ao is the orifice area
- ΔP is the pressure drop
- ρ is the fluid density
The discharge coefficient (Cd) accounts for:
- Flow contraction (vena contracta)
- Energy losses
- Velocity profile effects
It depends on:
- Beta ratio (β = d/D)
- Reynolds number
- Orifice plate edge sharpness
The β ratio significantly affects performance:
- Low β (0.2-0.5): Higher pressure drop, better accuracy
- Medium β (0.5-0.7): Balanced performance
- High β (>0.7): Lower pressure drop, reduced accuracy
Typical industrial applications use β between 0.4 and 0.6
