Propane without pain. Part 1: Simple things to keep you safe

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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, frying pan in hand. “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. In this first part of a two parter, we'll take up a few simple things about LP (for “liquid petroleum,” more commonly called propane) that can make your RVing experiences easier and safer.

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 many 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, 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.

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, 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.

Regulations mandate that 12 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.

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.

More next time.