Everything You Need to Know About Propane Tanks: Part I

You’ve finally reached your destination, set up your new Class A diesel motorhome or other RV, and are ready to cook a delicious meal before ending the night with a relaxing, hot shower. You might even enjoy a cold beverage to celebrate. While all of these activities differ from one another, they all have one thing in common: they need propane. But as versatile a tool as your propane tanks are for outdoor adventures, they need maintenance and proper use to keep them that way. 

In this first of a two-part series, we’re sharing everything you need to know about propane tanks from types to installation and use, to maintenance and disposal.

What are Propane Tanks Used for in RVs?

The easier question might be “what aren’t propane tanks used for?”  They power your refrigerator, your stove, heat water for showers, and help fuel smaller appliances like grills. However, they usually don’t power your HVAC system, as it’s more efficient to use a generator or electric source for that purpose. 

Types and Sizes of Propane Tanks

Most RVs come with propane tanks, but if you don’t have one, the type you’ll need is dependent on the class of your RV. There are two general tank categories: ASME tanks and DOT cylinders. 

ASME propane tanks can range in size from 20 lbs to over 100 lbs, and are usually fixed to the RV frame (non-removable). When you think of large motorhomes, these are the types of propane tanks they use.

Department of Transportation (DOT) tanks are smaller, thus making them more portable. These types of tanks are better suited for smaller RVs, travel trailers, or fifth-wheel campers.

How to Refill or Exchange Your Propane Tanks

Refilling ASME tanks requires bringing your RV into a designated refueling station. Most travel service stations like Loves, Flying J, and Pilot provide propane refueling centers, but you can also usually find one by searching online. Propane suppliers, such as Phillips Energy, Blue Rhino, Suburban, and Ferrellgas, may provide RV propane refilling services, too. Finally, check your local Tractor Supply and U-Haul storage sites for propane refills. 

Refilling DOT tanks is much easier, as they’re not attached to your travel trailer RV or other camper and don’t require you to pull up camp to refill. When transporting a DOT tank, make sure that it stays upright; in case of a tank blow, this will minimize the risk of it becoming a horizontal projectile. And for reasons we hope are self-explanatory, never transport a filled tank inside a hot vehicle! 

Note: All propane tanks that travel on highways need to be DOT recertified every 5 or 10 years after initial certification, depending on the tank. You can usually get this done wherever you purchase propane, but always call ahead to check.

Sometimes it’s more convenient to exchange your empty tank for one that’s already filled, but keep in mind that you’ll likely pay more per gallon if you do. This can be a great option though, if you’re in a hurry or if your current tank is nearing its inspection date as you can save the cost of the inspection and get a newer tank. Simply visit a propane provider and ask them for an exchange.

How to Check Your Propane Levels

For a quick estimate of how much propane you have left, there are a few common methods.

1.  Hot water test

Liquid propane has much higher thermal conductivity than the vapor above it, so it takes heat away from the cylinder wall more efficiently. Knowing this, you can pour a cup of hot water down the side of the tank, run your hand down the tank from the top and stop where it turns cool to find your propane level.

2. Weight (removable tanks only)

Those experienced with propane tanks can often simply pick one up to judge how full it still is. If that’s not you, use a portable hand scale. Some manufacturers make propane tank-specific scales, but a standard luggage scale usually works just fine. This is the most accurate and reliable method, since mass doesn’t change with temperature.

3. Pressure gauge

Install a pressure gauge on your propane tank, preferably one that accounts for temperature variations (not all pressure gauges do). Why? Because in hot weather, you may think you have more propane than you do if using one that doesn’t adjust. Using a pressure gauge won’t give an exact reading, but it can be more convenient than weighing. 

4. Ultrasonic gauge

This is the most convenient method, as the gauge connects to an app on your phone and shows the propane level in real-time.It works by sending an ultrasonic pulse from the bottom of your tank and detecting the liquid-vapor interface that occurs from the change in sound speed. This method is subject to fluctuations in temperature as the liquid expands with heat, but pro tip: don’t let your tank get close enough to empty for it to matter.   

Be sure to look out for our upcoming Part II for installation tips, maintenance advice, and more. Happy camping!

By Audrey Somero

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