Volume Flow Rate Conversion Formulas
Complete formulas for converting between different volume flow rate units including L/min, GPM, CFM, and specialized fluid flow measurements.
🌊 Basic Flow Rate Unit Conversions
Liquid Flow Conversions
Liters/min ↔ Gallons/min
Example: 100 L/min
100 L/min = 26.4 GPM
Cubic meters/hour ↔ L/min
Example: 3 m³/hr
3 m³/hr = 50 L/min
Gallons/min ↔ Cubic feet/min
Example: 50 GPM
50 GPM = 6.69 CFM
Gas Flow Conversions
Standard vs Actual Flow
Standard: 14.7 psia, 60°F
Actual: 20 psia, 80°F (540°R)
Factor = 0.735 × 1.038 = 0.763
Mass Flow to Volume Flow
Air: 100 kg/hr, ρ = 1.225 kg/m³
In CFM: 81.6 × 0.588 = 48 CFM
Volume flow: 48 CFM
🏭 Common Flow Rate Applications
| Application | Typical Flow Rate | Alternative Units | System Pressure |
|---|---|---|---|
| Garden Sprinkler | 2-5 GPM | 7.6-19 L/min | 30-50 psi |
| Household Faucet | 1.5 GPM | 5.7 L/min | 40-60 psi |
| Shower Head | 2.5 GPM | 9.5 L/min | 40-80 psi |
| Pool Pump | 40-100 GPM | 151-378 L/min | 15-25 psi |
| Fire Hydrant | 1000-1500 GPM | 3785-5678 L/min | 50-100 psi |
| HVAC Air Handler | 2000-10000 CFM | 3400-17000 m³/hr | 0.5-2 in WC |
| Natural Gas Pipeline | 1-50 MMSCFD | 0.7-35 million m³/day | 200-1000 psi |
🔧 Pipe Flow Rate Calculations
Basic Flow Equations
Continuity Equation
6-inch pipe, 5 ft/s velocity
Area: A = π × (3")² = 28.3 in² = 0.196 ft²
In GPM: 0.98 × 448.8 = 440 GPM
Flow rate: 440 GPM
Hazen-Williams Formula
8" pipe, C=130, S=0.001
Gravity flow: 174 GPM
Pump Performance Calculations
Pump Power Required
500 GPM, 100 ft head, η=0.75
Required: 20 hp motor
System Head Loss
1000 ft of 6" pipe, f=0.02, v=8 ft/s
Friction loss: 40 ft
🏢 HVAC Flow Rate Applications
Air Flow Calculations
Cooling Load to CFM
36,000 BTU/hr, 20°F ΔT
Required airflow: 1,667 CFM
Fresh Air Requirements
Office: 50 people, 17 CFM/person
In m³/hr: 850 × 1.7 = 1,445 m³/hr
In L/s: 850 × 0.472 = 401 L/s
Outside air: 850 CFM
Water Flow in HVAC Systems
Chilled Water Flow
100 tons, 12°F ΔT
In L/min: 200 × 3.785 = 757 L/min
In m³/hr: 757 × 0.06 = 45.4 m³/hr
Chilled water: 200 GPM
Hot Water Heating
500,000 BTU/hr, 40°F ΔT
In L/min: 25 × 3.785 = 94.6 L/min
In m³/hr: 94.6 × 0.06 = 5.7 m³/hr
Hot water: 25 GPM