Whether you’re restoring a vintage trailer or simply maintaining your RV, one critical system that can’t be overlooked is propane. From cooking to heating, propane plays a major role in off-grid comfort—but it must be handled safely and responsibly. That’s where propane tank certification comes in.
The 12-Year Rule: What Is It?
In the United States, portable DOT (Department of Transportation) propane cylinders, such as the ones commonly used on RVs and travel trailers, must be recertified 12 years after their manufacture date. After that, they require recertification every 5 or 7 years, depending on the type of inspection performed.
This is a nationwide requirement governed by the U.S. Department of Transportation, and enforced by propane suppliers, refill stations, and transport authorities.
How to Read the Date
Each propane cylinder has a manufacture date stamped on the collar of the tank, usually in the format “MM-YY” (for example, “06-18” means it was made in June 2018). That’s the date from which the 12-year countdown begins.
If your tank is beyond that window, you’ll likely be turned away when trying to refill it—unless it’s been recertified.
What Is Recertification?
Recertification involves an inspection to make sure the tank is still safe for use. There are a few different methods, including:
- Visual inspection: A certified technician looks for signs of rust, corrosion, damage, or leaks.
- Proof pressure test: The tank is filled with water and pressurized to check for leaks.
- Ultrasonic examination: High-tech testing for integrity without opening the tank.
Once recertified, the tank will be marked with a new date and either a letter code or sticker, depending on the type of test performed.
Where to Get It Done
Most propane refill stations won’t perform recertifications, but many certified propane service centers, RV dealers, or welding supply stores will. It’s a good idea to call ahead and confirm. Find a recertification
The cost for recertification is usually modest—often under $30—and a lot cheaper than buying a new tank, especially for vintage or hard-to-find cylinders.
Can I Reuse Vintage Tanks?
If you’re restoring a vintage trailer, you might be tempted to reuse the original tanks for authenticity. While this is possible, they must be certified and meet modern safety standards. In some cases, the older tanks can’t be recertified and must be replaced.
DOT vs. ASME Tanks
It’s worth noting that DOT cylinders are portable and used on most travel trailers, while ASME tanks are permanently mounted (often on motorhomes) and do not require periodic recertification—but they should still be visually inspected regularly.
Bottom Line:
If your trailer’s propane tanks are over 12 years old and haven’t been recertified, it’s time to get them checked. It’s not just a legal requirement—it’s a safety one. Stay compliant, keep your trailer functional, and enjoy peace of mind at your next rally or campsite.
