Without question, the RV propane tank is one of the most important nerve centers of any RV. From providing the fuel you need to cook your food to the refrigeration required for cooling it. And granting you the hot water you need for everything from cleaning to showering. The camper propane tank serves many functions in an RV.
RV propane tanks are not complicated, but there are some important differences and options that are important to take note of.
Because RV propane tanks do so much to add to the comfort and enjoyment you experience in your RV, let’s get to know them a bit better.
Types of RV Propane Tanks
There are two types of propane tanks found on RVs: ASME tanks and DOT cylinders.
ASME tanks, used most often on motorhomes, are approved by the American Society of Mechanical Engineers. In this case, the RV propane tank mount is the frame of the motorhome itself, so ASME tanks are not removable.
DOT cylinders are used on travel trailers, fifth wheels, truck campers, and some small motorhomes. These are approved by the Department of Transportation. DOT cylinders may be mounted in exterior compartments. Or, RV propane tank holders on the tongue or bumper of the trailer.
RV Propane Tank Sizes
RV propane tank sizes vary widely depending on the type of tank and RV that you have. The tanks’ contents are measured in pounds. There are propane bottles as small as 7 pounds and ones as large as 420 pounds. Which size you have on your rig will vary a lot based on the rig itself.
ASME tanks on motorhomes can vary significantly depending on the size of your RV. While a small Class C motorhome may have a single 20-pound ASME motorhome propane tank, it is not uncommon for large Class A motorhomes to have tanks that hold 80-100 pounds of propane.
DOT cylinders used on travel trailers and fifth-wheel trailers are typically much smaller, compared to their ASME counterparts. However, the total carrying capacity of these units can sometimes rival those of large motorhomes. A small travel trailer or truck camper will typically have a single 20-pound DOT cylinder. By comparison, a large fifth-wheel camper may carry a series of 40-pound DOT cylinders. This gives the RV a propane capacity of over 100 pounds.
How do you know the amount of propane you will need?
Depending on your RV type and tank type, you may be able to expand your RV propane tank setup. If you plan to expand your RV propane system, be sure to work with a professional, certified in propane and propane accessories. Someone who can give recommendations on the tank size and setup that will work best for your RV.
That said, the amount of propane you need will vary considerably depending on what kind of camping adventures you’re taking. For instance, if you’re mostly traveling in warm-weather locations and staying at developed campgrounds, you may only need a little bit of propane to use your gas stove. On the other hand, if you’re planning to boondock off the grid in a place where your heater is required, more propane will be necessary to keep you comfortable for longer.
The best way to determine the correct propane tank sizes for your needs is to take a short camping trip of the type you desire. This way you figure out how much propane you’re using each day by checking the levels. Then, you can get a better sense of how much propane will meet your needs in the long run.
RV Propane Tank Gauges
If you have a motorhome with an ASME tank, it probably has an RV propane tank gauge built into it. This gauge has a needle showing how much propane is in your tank. This type of RV propane tank gauge utilizes a float inside the tank to measure the propane level. No matter which kind of tank you have, you’ll want to take advantage of an RV propane tank gauge. These gauges let you know how much propane is in your tank so that you don’t run out and put yourself in a difficult situation.
DOT cylinders utilize different types of RV propane tank gauges, or sometimes none at all. While some higher-end DOT propane cylinders may have a built-in RV propane tank gauge, most will require an aftermarket gauge of some kind to be added.
RV propane tank regulators are another important piece of equipment that ensures the safe operation of your propane tanks. Here’s a guide to everything you need to know about RV propane tank regulators.
RV Propane Tank Covers
While ASME tanks are affixed to the frame of a motorhome and take up part of the exterior storage of the RV, DOT cylinders are often kept outside of the RV on the trailer tongue or bumper. Because of this, many RVs have RV propane tank covers to protect the cylinders from road grime and weather conditions.
An RV propane tank cover is typically made of heavy-duty plastic or polypropylene. They come in a wide variety of colors and sizes to accommodate different-sized DOT cylinders and setups with multiple tanks. Tank covers are easy to remove and replace if necessary.
RV Propane Tank Holders
As mentioned previously, ASME tanks are affixed directly to the frame of your motorhome, but many DOT cylinders are kept on the outside of the RV.
Propane cylinders kept on the outside of the RV require an RV propane tank mount or holder. These holders are designed to keep the propane tanks safe and secure, while still allowing easy access for refilling.
An RV propane tank holder is made of powder-coated steel or aluminum. It s typically equipped to hold two cylinders of the same size. They have a base plate, which is usually welded or bolted to the frame of your RV, that holds the weight of the two cylinders. The tank holder will then have a heavy-duty rod coming up from the center of the base plate. And a bracket affixed to the top of the rod to hold the two tanks in place. Some racks may come equipped with hoses and a changeover switch to change the cylinder from which your propane system is drawing. If not, a changeover switch can be added.
Filling an RV Propane Tank
Because ASME tanks are mounted directly to the frame of your motorhome, you will have to drive your RV to a propane dealer or station to get your tank filled. Some stations allow you to pump your own propane. Others require a certified employee to pump the propane for you. Be sure to check with the dealer you are working with to determine how they handle refills.
Because DOT cylinders are not permanently mounted to the RVs that utilize them, they can be removed and taken to your propane dealer for refilling.
If you find yourself at a campground, and you are running low on propane, be sure to check with the campground office. Many campgrounds offer propane refill services on-site. Those that don’t will at least be able to direct you to a nearby dealer.
One important thing to note about filling an RV propane tank is that propane tanks may only be filled to 80% of their total capacity. The reason for this is that propane expands when it is subjected to heat. If a propane tank is filled to 80% capacity when it is cold outside, that same amount of propane, in the same tank, may actually take up 85-90% of the capacity of the tank on a much warmer day.
Parts of an RV Propane Tank and How They Work
Every RV propane tank has a few key fittings that control filling, measuring, and releasing propane safely. Knowing what each one does helps you fill your tank correctly and spot problems early.
A properly filled tank holds about 80% liquid propane, with the rest left as vapor. Your RV’s appliances run on that vapor, which is drawn from the top of the tank. If liquid propane gets into the lines, it can damage your regulator and appliances, which is why the 80% limit matters.
Fill Port and Overfill Protection
The fill port is where propane goes in. Most modern tanks have an automatic stop-fill device, a float on an arm that rises with the liquid and shuts the fill valve when the tank is full. A stuck float or bent arm can keep it from working, so don’t rely on it alone.
Bleeder Valve
The bleeder valve, also called the fixed liquid level gauge, is a small vent connected to a tube that ends at the 80% mark inside the tank. During filling, the technician opens it. When propane reaches 80%, a white mist of liquid propane sprays out, signaling that it’s time to stop. If a filling station skips this step, consider taking your business elsewhere.
If your tank is overfilled, keep the main valve closed and drive to an open area away from people and buildings. Turn off all ignition sources, park with the tank downwind, and open the bleeder valve until only vapor comes out. If you’re not comfortable doing this, ask a propane technician for help.
Fuel Level Gauge
On built-in ASME tanks, the fuel level gauge uses a float and a magnet to measure the propane level. A sensor outside the tank reads the magnet and sends the level to the gauge on the tank and the monitor panel inside your RV. Because there’s no wiring inside the tank, it’s a safe design, but readings can be off, so treat them as an estimate.
Pressure Relief Valve
The pressure relief valve releases propane vapor if pressure inside the tank gets too high, such as when the tank overheats. Its only job is to keep the tank from rupturing. If you hear or smell it venting, turn off all ignition sources and move away from the RV until it stops.
Main Valve
The main valve, or service valve, sends propane vapor to your RV. Turn it counterclockwise slowly to open it. If you open it too fast, a built-in safety device called the excess flow valve can trip and cut off the flow. To reset it, close the valve, wait a few minutes, and open it again slowly.
- Close the main valve before you refuel your vehicle and whenever you smell propane. If you smell a leak, also turn off your battery disconnect switch to avoid sparks.
- Turn off appliances that use propane, and follow the rules for tunnels and ferries, which may require the tank to be closed.
- Install and test a propane leak detector inside your RV.
Propane Tank FAQs
Let’s finish out this article! Here are some answers to your most frequently asked questions about RV Propane Tanks!
What size are RV propane tanks?
Propane tanks come in a wide variety of sizes for different uses. The size of motorhome or travel trailer you have will have an impact on what size your RV propane tanks are. That said, the tanks may be 20 gallons, 30 gallons, 40 gallons, or even larger. Especially if you have a special rig set up for full-timing or long-term camping.
Where is the propane tank on an RV?
The RV propane tank may be in a couple of different locations, again depending on exactly what kind of setup you have. For instance, propane tanks are commonly found on the front of travel trailers, visible from the outside. With motorhomes, they’re located under the coach with other mechanical systems and equipment (like your plumbing system).
Is it cheaper to fill propane or exchange?
It’s cheaper to fill existing propane bottles than to exchange yours for brand new ones. You can purchase a propane fill at many camping stores and campgrounds. As well as dedicated locations that do nothing but sell propane.
That said, tanks do expire eventually, and it’s important for your safety to ensure that you have up-to-date tanks and exchange them once that happens.
Is it OK to drive with the propane on?
This is a very frequently asked question. Given that most RVers want to keep the contents of their fridges cool while they’re traveling, the reality is that most campers do travel with their propane on. That said, leaving your propane on while you drive does expose you to some additional risks if you’re in an accident. It’s likely safer to turn your propane gas cans off entirely. (If you enter a tunnel or get onto a ferry, you may be required by law to do so.)
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