Propane tanks can be hazardous when used or maintained improperly. Because they’re often left outdoors, they’re prone to rusting. Using a rusted propane tank poses serious safety concerns, so what do you do with it?
You should dispose of or recycle a rusted propane tank and avoid using it if it’s too corroded. Make sure to follow local regulations on the disposal of hazardous materials. If it’s only slightly rusted, you can clean the propane tank using steel wool, vinegar, and baking soda.
The rest of this article will elaborate more on the dangers of using a rusted propane tank, preventative measures you can take, and how to clean any rust from your tank. Let’s get started.
Is It Safe to Use a Rusted Propane Tank?
It isn’t safe to use a rusted propane tank because the tank walls need to withstand the high pressure of the gas stored inside. Rusting weakens the metal and can potentially lead to leaks or even an explosion. It also interferes with the normal functioning of the cylinder.
Propane is in a gaseous state at room temperature and pressure. In order to transport large amounts of the gas, it’s compacted under high pressure. The increased pressure causes the propane gas to condensate to liquid form.
The steel walls of the propane cylinder are specifically built to withstand between 100 to 200 psi. Rust forms when iron oxidizes, and the process of rusting significantly weakens the iron. Because steel is an alloy of iron, it’s also prone to rusting.
If you compare steel and rust, you’ll quickly notice that it isn’t merely a color change. Steel is a hard metal, whereas rust is a powdery red substance. Naturally, when parts of a propane tank are rusted, the cylinder loses its ability to withstand the high pressure of liquid propane.
At the very least, this could lead to propane leaking out of the tank. Any spark around the propane gas will quickly ignite. The stored propane fuels the fire, allowing it to continue burning. Since the propane isn’t coming out of the controlled valve, it’s more difficult to put out the fire.
There are a few ways that rust impedes the normal functioning of a propane tank:
- Moisture can enter the tank and mix with the gas. This changes the pressure and temperature of the propane inside the cylinder. Also, moisture causes the fuel to flow out inconsistently, which is a major fire hazard.
- Heat absorption through the tank walls. The rust allows the ambient temperature to affect the internal temperature of the tank. This is because the properties of rust (iron oxide) are not the same as steel (iron alloy).
- Fuel lines can get clogged and build up pressure. Rust is powdery, and the molecules don’t have a strong bond with each other, so it’s easy for rust particles to get into the different parts of the tank and clog the fuel lines. This causes the pressure to build up, which could potentially lead to an explosion.
- Dents and other structural deformities. As the structural integrity of the cylinder is compromised, the weaker rusted area will give in to the pressure and warp the shell, causing dents. A dented propane tank is more prone to explosion.
A rusty propane tank can explode if the rust is widespread enough to cause a leak, which can cause a fire. Furthermore, it could potentially lead to a BLEVE — an explosion that occurs when a pressurized container ruptures at high temperatures.
Firefighters are typically trained to extinguish a propane tank fire by turning off the valve. However, because a rusty tank is structurally compromised, they’re trained to expect a BLEVE to occur. BLEVE is an acronym for “Boiling Liquid Expanding Vapor Explosion,” which simply means that the liquid propane has heated up enough to boil and explode the rusty tank.
When a propane tank explodes, the fragments projecting away from the explosion are just as dangerous as the fire and the blast wave of the explosion.
It’s worth noting, however, that such explosions are rare despite the potential fire hazards that are associated with propane gas tanks. It’s only in the event of a widespread fire or a leaking rusty propane tank that there’s a significantly increased risk of explosion.
How to Extinguish a Propane Tank Fire
Try to turn off the propane safely, if possible, and use a fire extinguisher. It’s essential that you leave the area immediately, even if you don’t smell any propane.
While modern propane tanks are fitted with a pressure-sensitive release valve as a safety measure, there are still many propane gas-related incidents reported every year. More often than not, users aren’t aware that the tank is rusty or that the valve is leaking. In any case, if you ever find yourself around a propane tank fire, here are some tips on what to do:
- Call emergency services. Try to reach the phone as fast as possible because professional firefighters and other first responders will be better equipped to handle the fire. The earlier you call, the more time they have to reach you and provide help.
- Extinguish the fire by smothering it. Ideally, you should have a fire extinguisher nearby to put out the fire, and you should keep the propane tank outside only. If you don’t have a fire extinguisher, baking soda is a good alternative to smother the fire temporarily.
- Evacuate the area. After attempting to extinguish the fire, make sure you’re as far away as possible from the propane tank. This is especially important if you smell a leak that you’re unable to contain.
- Don’t put water on a grease fire. Propane tanks are typically used around outdoor grills or kitchens, where grease fires are a possibility. While water is good for putting out a fire, you should never use water to put out a grease fire because it’ll only make it worse.
Most importantly, you should act quickly and try to get away from the propane tank as fast as possible to avoid the risk of injury. As mentioned above, if the liquid propane is heated enough to start boiling, there’s a serious risk of explosion.
How to Remove Rust From a Propane Tank
You can remove rust from a propane tank using vinegar, baking soda, and abrasives. Painting the propane tank also prevents rust from spreading by providing a waterproof barrier.
Firstly, only use a propane tank after cleaning if the rusting is superficial. If the rust is extensive, it’s better to err on the side of caution. To remove rust from a compressed gas cylinder, first, ensure that it is completely empty. Don’t attempt to clean it thoroughly when it’s completely filled.
The following are a few ways you can use to remove rust from the external surfaces of the propane tank. Before starting, you can use a wire brush or steel wool to reduce the amount of surface rust you’re dealing with:
- Soak the tank in vinegar. One of the best known rust removers that everyone has access to is vinegar. Seal the valve and submerge the tank in a 1:1 vinegar and water solution. You can leave it soaking for up to 24 hours. Then scrub the external surfaces thoroughly with steel wool and baking soda, wipe down the tank, and repeat if necessary.
- Use sandpaper to remove the rust. Save yourself some elbow grease by removing the rust using sandpaper. If you have access to a sander, try using high-grit sandpaper, being careful not to shave too much of the metal underneath.
- Use chemical rust removers. You can purchase specially formulated rust-removing chemicals that work faster than vinegar. However, these chemicals are much harsher, and you should take precautions to prevent any injuries.
Once you’ve ensured that there’s no more rust on the surface of the cylinder, apply a layer of rust-resistant paint. Be sure to apply the paint on every exposed surface because rust can easily spread under the paint from a small area.
Prevent Rust Formation on Your Propane Cylinder
Whether you have a brand new tank or one that you’ve gone through the trouble of de-rusting, preventing rust formation is an essential part of maintaining the tank. Here are a couple of things you should do to prevent rusting:
- Avoid prolonged exposure to moisture or salt, as they accelerate rusting.
- Regularly inspect your propane tank and apply a coat of paint as a protective measure.
It’s best to dispose of a rusted propane tank, especially if it’s significantly corroded. Preventing rust formation is preferable, but if you see any surface rusting, try to get ahead of the problem and remove it.
Otherwise, you should safely dispose of the propane cylinder, as using a rusty propane tank can lead to an explosion, causing a fire or other serious injuries.