Monday, October 3, 2022


Propane safety made simple – Part 1

By Russ and Tiña De Maris

The old joke talks about the fellow unexpectedly hurtling toward earth after being tossed out of a plane. Struggling to figure out the rip cord on his parachute, he spots another man flying upward toward him. “Hey!” he calls out. “Do you know anything about parachutes?”

“Nope!” shouts the upwardly moving character. “Do you know anything about propane stoves?”

It’s likely that if you ever find yourself in a parachute, you’ll have had a lot more training on rip cords than many who take up RVing get on propane safety. This month we’ll cover a few simple things about LP (for “liquid petroleum,” more commonly called propane) that can make your RVing experiences easier and safer.

The nature of the beast

First, a little background about propane. Under pressure, propane is a liquid – colorless and odorless. “But, it stinks when they refill my propane tank!” you say. Sure enough, an odorant is added to commercial propane. But here’s a warning: Not everyone can smell the odorant; a cold or sinus or olfactory problem can eliminate this warning odor. Test your RV’s gas detector regularly.

While water boils at 212 degrees, propane boils at -50 degrees. Mind you, propane in your tank is definitely under pressure. As that pressure is released, the liquid absorbs heat. If you watch the tank refilling process, you’ll see a stream of what looks like steam coming out of a small valve in the tank. Stick your finger in it and you’ll find it not hot like steam but extremely cold – enough to freeze your skin.

Propane, unlike natural gas used in homes, is heavier than air. This may cause you to think if you get a propane leak in your rig that it will sink to the floor. But moving air currents will stir the propane up, causing it to mix with the air, putting it anywhere, and that could mean harm if it finds a source of ignition. If you think you have a gas leak, GET OUT OF THE RIG, and DON’T turn on the light to see the door. Leave the door open, allowing the gas to dissipate.

Happily, propane requires oxygen to burn, and in a very narrow range of proportion. Too much propane to air, or too little, and it won’t burn. For some, that can bring on a lax attitude toward safety: They’ve smoked around an area where tanks were being filled, they’ve fueled up the tow vehicle while the propane valves were open, blah, blah, blah. “And I’ve never had a problem!” It only takes one time of having the right propane-to-air mixture with a source of ignition to have your first – and last – problem with propane.

The upshot? Don’t use a match to check for propane leaks. Don’t leave your pilot lights lit or appliances with automatic ignition turned on when fueling your vehicle or your propane bottles.

Keeping it contained

To carry and safely contain propane, RVs are equipped with LP containers. Technically speaking, only a motorhome has a propane “tank” permanently mounted on the rig. Trailers and campers have portable cylinders that have different safety regulations to live up to.

Portable containers are generally painted white. This isn’t just to make your rig look pretty: Propane is highly responsive to heat, so painting your container white will help it reflect light and heat, hence staying cooler. We’ll come back to how important this is in a bit. Keeping your LP containers painted and tending to scratches will keep you safer. In the photo, the collar or “handle” of this tank is showing rust. If the tank were in a similar condition, it’d need a paint job for sure – with a preliminary sanding down of the rust.

Regulations mandate that 10 years after manufacture, portable cylinders must be inspected and “recertified” as safe. That recertification must be repeated every five years after that. Not every LP refilling station is sticky about this, and there are plenty of conscientious LP retailers who get blasted by an irate RVer whenever they refuse to refill a container that’s out of date. Still, they’re looking out for your safety, and it doesn’t cost much to have a cylinder recertified.

One more point on the subject of safety: Motorhomes and nearly all other RVs have tanks fitted with valves that stop the intake of gas when full. On portable containers (on trailers), they’re called OPD valves, for “overfill protection devices.” Propane station attendants remind us that these are mechanical devices, and they’re about as accurate as the gas gauge on your car. It is possible (more likely probable) to overfill an LP container equipped with an OPD valve. This can become a serious problem. How so?

Every LP tank is equipped with a pressure relief valve. Because of the highly expansive nature of LP gas (its volume increases dramatically with increasing temperature), here’s a scenario you should never forget. One day you and your fifth wheel are in Montana, getting ready to get out of that cold nastiness and head south for the winter. Your LP guy fills up your tank, and carelessly overfills it. A couple of days later you’re in Arizona, and the temperature is much higher. LP in the “full” tank expands dramatically. The gas pressure relief valve “pops off,” allowing a large volume of LP to suddenly flood into the nearby atmosphere, where Joe Schmo is walking by, lit cigarette in his mouth. You get the picture.

Check for gas leaks often by using this!
Russ & Tiña De Maris write: “We keep our natural gas leak detector tucked in the door pocket of our tow vehicle so we can check for leaks when we reconnect an LP bottle after filling. We also use it whenever we make up a new connection on a gas line, or ‘think’ we might have a leak. Here’s one you can pick up for a good price with lots of good reviews.”

The only SAFE way to fill an LP tank is by either weight (which few stations do) or by opening a little valve on the tank called a 20 percent valve (some call it a spit valve) while filling the tank. When liquid propane begins to “spit” out of the 20 percent valve, the attendant should IMMEDIATELY STOP filling the tank. Filling beyond this point is completely unsafe. We’ve had more than one argument with a careless station worker over this matter, but we’re the ones that have to ride in the rig and suffer any consequences of stupidity.

One more thing about OPD valves: The container in the picture has the peculiar “3-cornered valve handle.” That’s significant – if the valve handle is any other shape, it doesn’t have the OPD valve. There are still a few out there, kicking around in spider-infested sheds. A reputable LP retailer won’t fill that old antique up, and rightly so. If you see one, you might consider it a museum piece. But I don’t think I’d want one in my museum – any more than I’d want a loaded hand grenade.

Our primer on LP safety doesn’t end here. We’ll cover some more ground in our next chat. Meanwhile, here’s the recap:

Smell propane or your LP leak detector goes off? Get out, and don’t flip any switches on the way. Keep your tanks painted and recertified. Don’t leave your pilots lit or appliances turned on when you head in for a refill. Don’t let the gas guy overfill your tank. And remember, the rip cord is that thing with the big metal ring on the end of it.


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Benny H Smith
1 year ago

I just searched for cost for recertification on my 30 lb tanks vs buy new. Considering the recertification only good for five years. It looks cheaper to buy a new tank than recertification. Am I missing something?

1 year ago

I’ve never had anyone weigh my tank when refilling, even though most (maybe all) have a scale. They’ve always used the 20% valve.

Tommy Molnar
1 year ago

While I’ve read here and other places that propane tanks need to be recertified every 10 years, the ‘pros’ at Amerigas and Ferrellgas both will tell you it’s 12 years. I just bought two new tanks and it says on the collar that they should be inspected after 10 years. The Ferrellgas guy told me he had just taken a refresher course a month prior. Even the guy at my local U-Haul store said it was 12 years, and he too had just taken a course at the Amerigas station. Who is to be believed?

2 years ago

Since it’s important to make sure your propane tank on the RV stays painted white. Why are the small 1 lbs bottles painted dark green?

2 years ago

I cant wait for the next lesson.

Dick and Sandy now home near Buffalo, NY
2 years ago

The custom propane lines in the RV’s and motor homes that feed the stoves and furnaces and water heaters and the 2 way fridges are not made by the manufactures of those rigs. They are custom made by nationally certified companies that specialize in making propane lines. That means what ever service center you bring your rig in to replace one of those lines that has a leaky fitting or a leak in that hose can not make up that hose for you. The hose must be totally removed from that rig, taken to a certified propane hose manufacturer and built to replace that hose to the exact size, length and with the correct fittings as well as leak tested by the manufacturer before bringing it back to your repair service to be replaced. Depending on how close you are to a propane repair service, that can take hours, days and more. So be kind to your propane system.

Robert Julich
2 years ago

Please let folks know how dangerous it is to bring 5 gallon propane tanks into the RV. Twice I have had to have serious discussions with those who bring the tanks inside their units to run the buddy propane heaters. They believe that if it is OK to bring in the one gallon disposable cylinders it’s OK for bigger cylinders. Big big mistake!

1 year ago
Reply to  Robert Julich

A) 20lb are not truly 5 gallon
B) 1lb are not 1 gallon
C) its NOT safe to bring 1lb tanks inside either, for all the same reasons. Its a smaller volume thus risk but still could go quite deadly.
D) my box of 1lb tanks travel in the truckbed, less climate controlled but more vented.

Gene Bjerke
2 years ago

Not an RV story, but I once lived in an apartment that had an old gas stove which didn’t have a starter on the oven. I was having a hard time getting the oven lit, when there was a big WHOOSH! and I found myself in the middle of the room feeling like the guy in the cartoons with a black face and smoke coming from his mustache. I quickly learned respect for propane.

Bob Harnish
2 years ago

I haven’t seen a scale used for a long time. In Arizona and many other places they use a gallon and tenth meter very much like a vehicle gas pump. And of course they are stickered by that particular county’s weights and measurements group. The last time we were in Texas several years ago they scaled the tank and I commented about it to the pumper. He in turn said “the railroad commission is the guru of propane in the state”. That is all that needed to be said.

2 years ago
Reply to  Bob Harnish

The problem with the meter is , it doesn’t account for the propane that might be in the tank, if it isn’t empty when they started filling it.

The ‘spit’ valve and weight are the way to go.

1 year ago
Reply to  alcomechanic

Spit valves clog on rare occasion. Weight is the only true standard. Volume is seldom a good idea just as you said…i don’t run DEAD every time.