As we’re in the start of camping and barbecuing season, and with propane grilles being the most popular form of grilling, propane tank users need to take precautions when using them. Few realize that their white tank of propane tucked under the grille or attached to their camping trailer, can be lethal. They are a bomb waiting to go off, said one industry expert.
To find out more about propane cylinders, I spoke to Ernest Steigerwalt of Steigerwalt Associates, an Allentown, Pa firm specializing in gas cylinder worldwide. Steigerwalt, president of the firm, is certified by the U.S. Department of Transportation as an authorized gas cylinder inspector. His firm also inspects fire extinguisher cylinders.
Steigerwalt said burns and explosions occur mainly from “flashbacks,” a condition when the wind, for example, blows the flame to a leak somewhere in or along the fuel line. This situation can occur during grilling or ignition, but only when fuel is leaking.
As a professional propane cylinder inspector who is often called upon to testify as a professional witness in court suits emanating from cylinder failures, Steigerwalt admits that propane tanks are dangerous if handled improperly, and should be treated with the same respect as a loaded gun.
The propane cylinder expert points out the following facts about propane that makes it so volatile. Said Steigerwalt, “One of the properties of propane is that it is heavier than air. It’s also a petrol chemical as opposed to natural gas. When exposed to air, it vaporizes. And because it’s a liquefied gas stored under pressure, it expands 314 times in volume. Pressure in the cylinder is related to the temperature at which the propane is stored and cylinder pressure is temperature dependent.”
When asked what precautions a grille owner should take to prevent an accident, Steigerwalt offered these suggestions:
*Never store a propane cylinder in a house or garage.
*Keep a cylinder upright at all times because you want the safety relief valve to be in the vapor space of propane cylinder, not in the liquid.
*Have the cylinder refilled at a reputable dealer who fills by weight. Cylinder recharging is critical in that they should not be overcharged. Sometimes an attendant will overfill a tank which completely changes the safety feature built into the tank. An empty propane cylinder’s weight is determined by TW or “Tare Weight” as stamped on the cylinder’s top. A typical empty propane cylinder weighs about 18 pounds.
*After refilling, make sure the plastic “POL” outlet safety plug is installed on the valve outlet.
*Never leave a propane cylinder is the trunk or cargo area of a vehicle for any length of time, and make sure it’s secured upright.
*After refilling and reassembly of the hose, check all connections for leaks by applying soapy water to them. It there’s a leak, the soapy water will bubble.
*Check all vents and jets for melted cheese, grease, bug, spider or chipmunk nests that could block the proper mixture of air and fuel. This could also create a flashback.
*Always turn off the cylinder’s service valve after use.
*If you smell propane (you actually smell Mercaptan that is added to propane as an odorant and safety feature because propane by itself is odorless), immediately turn off the the valve as there’s obviously a leak.
Aside from these safety precautions, the next question many grille and RV owners have is when to refill their cylinders. It’s problematic when beginning to grille some food and the cylinder “kicks.” Steigerwalt says it’s a frustrating situation that has few easy solutions especially if you’re camping at a remote location. Said Steigerwalt, “The most accurate method to determine if your cylinder has propane remaining is to weigh the tank on a bathroom scale. Subtract the weight from the cylinders’ totally filled weight. This will give you the remaining pounds of fuel. To calculate the remaining burn time, a good rule of thumb to follow is that a single burner grille burns about one pound of propane an hour. Double that for two burners.”
Steigerwalt goes on to say that the gauges advertised for grilles are not accurate because propane is not measured by pressure but by weight. “The only type that are somewhat accurate are the float type gauges. But they cost as much as an extra tank. And the little stickers being sold for cylinders are not much better. You can get the same effect by checking sweat of condensation on the tank on a hot day. Where the sweat ends, that’s your fuel level. But that only indicates the remaining burn time. Best bet is to keep a filled spare,” he concludes.
For camping trailers with inside propane stoves and refrigerators, Steigerwalt recommends turning off the gas at the tank and appliances when the vehicle is in motion.
In the past, the professional metallurgist has been summoned to testify in a court case when a car rear-ended a Winnebago camper. “From the testimony I heard, the RV literally exploded in flames when the propane tank ruptured,” recalls Steigerwalt.
Taking the time to check your cylinders and connections periodically, will go a long way in making your camping trip and cook-out, safer and more enjoyable.
Nick Hromiak has been an outdoors and automotive writer for over 30 years. He's been published in numerous national and state-wide outdoor magazines and newspapers.