Propane Tank Sizing

Written by Rick Feiler

Are your propane tanks sized properly? With the weather being at or below the average temperature this year, the proper tank size is the most important part of the propane system. If you size the tank too small, the tank will not produce enough vapor pressure to operate your appliance. Therefore, several questions need to be considered when sizing the tank. 1) What is your total BTU load? 2) What is the Wetted surface area of the tank (The liquid level in the container)? 3) What is the average winter temperature in your area? 4) What’s the BTU load of your system?

To help you answer these questions you first need to know the amount of pressure inside the propane tank. This is determined by the ambient outdoor temperature. Therefore, the lower the outdoor temperature the lower the tank pressure will be.  The lower the tank pressures the less vapor pressure you will have flowing to your appliance. Next, when sizing the tank, you will need to know how many appliances are going to be operated and what the BTU output is of each appliance. Once you add these up, you are ready to determine the tank size and regulator which will fit the needs of your system. (See manufacturer’s charts below):

Now that you know the size of the tank and the proper regulators needed, you now need to determine the proper line size. On larger tanks, we will need to first determine the proper line size for the line running from the tank to the house (the high pressure line). This line will carry the total load.  Then, you’ll need to size the lines inside in the house. Below are charts from the REGO LP-GAS Serviceman’s manual for the first and second stage system discussed above.

Choosing the proper equipment is a vital part of the process installation. At Tarantin Industries we have the equipment you’ll need for all aspects of your installation. Please feel free to contact us with any questions.

Rick Feiler

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