LPG Flow Rate Calculator
Calculate Mass and Volumetric Flow Rates for LPG Installations
Kilowatts (kW)
BTU/hr
MJ/hr
Propane (Commercial)
Butane (Commercial)
Mass Flow Rate:
Volume Flow Rate (Gas):
Volume Flow Rate (Liquid):
Total Energy Output:
Understanding LPG Flow Rate Calculations
LPG (Liquefied Petroleum Gas), whether propane or butane, is a high-energy fuel source used for heating, cooking, and industrial processes. Calculating the flow rate is essential for sizing pipes, selecting regulators, and ensuring that storage tanks can vaporize enough gas to meet the demand of the appliances.
Key Technical Parameters
To calculate flow rate accurately, we use the specific energy values of the gas types:
| Property | Propane | Butane |
|---|---|---|
| Calorific Value (Mass) | 12.88 kWh/kg | 12.69 kWh/kg |
| Liquid Density | 0.505 kg/L | 0.585 kg/L |
| Gas Density (at STP) | 1.88 kg/m³ | 2.48 kg/m³ |
How to Calculate Flow Rate
The calculation follows a logical progression from heat demand to mass and then to volume:
- Determine Total Heat Load: Sum the input ratings of all appliances connected to the system.
- Calculate Mass Flow: Divide the total load (in kW) by the energy content per kg of the fuel. For Propane, this is Load / 12.88.
- Determine Volume Flow: Convert mass flow to volume based on the density of the gas in its gaseous or liquid state.
Practical Example
If you have an industrial heater with a rating of 100,000 BTU/hr using Propane:
- Step 1: Convert BTU to kW (100,000 / 3,412.14 = 29.31 kW).
- Step 2: Mass Flow = 29.31 kW / 12.88 kWh/kg = 2.27 kg/hr.
- Step 3: At standard pressure, this translates to roughly 1.21 m³/hr of gas flow.
Note: This calculator assumes standard pressure and temperature. High-pressure systems or extreme temperatures may require specific gravity and compressibility corrections.