How to Refill Propane Cylinders

Propane, also known as liquid petroleum (LPG), is a hydrocarbon produced during natural gas processing and crude oil refining. Listed by the 1990 Clean Air Act as one of the cleanest burning fossil fuels available, it's virtually odorless and clean burning. Because it's considered nontoxic and doesn't contaminate soil or water, it's considered an ideal "green" fuel. As a fuel source, it's ideal for use with barbecue grills, stoves and fireplaces. While larger tanks are available for home heating purposes, a smaller 20 gallon tank is typically used for the barbecue or fireplace. If the tank is empty, there are certain methods you should employ while filling it.

If you suspect a leak in the line of your propane tank, perform a "bubble test" to verify.
  1. Rest the propane tank in a propane tank caddy or "nanny" in the trunk of your car. Available through propane tank suppliers such as U-Haul, the "nanny" secures the tank in an upright position and prevents it from falling or rolling during travel.
  2. Close the cylinder valve and seal with a plastic plug. Even if the cylinder appears to be empty, residual propane settled at the bottom of the tank will expand with temperatures and may escape from the tank. A plastic plug, available through propane suppliers, protects cylinder threads and prevents propane from leaking into the car interior.
  3. Transport the propane tank to a refill station. Many gas stations and garden centers have filling stations where a trained attendant will refill the propane tank. Never attempt to fill or modify the propane tank yourself.
  4. Ask the attendant to inspect the propane tank. If it's damaged, rusted or doesn't have an overfill protection device (OPD), exchange it with the refilling station. Most stations have replacement tanks that are inspected and up to code. According to the National Fire Protection Association, an OPD shuts off the filling device when the tank reaches 80 percent capacity. As of April 1, 2002, an OPD is required on all propane tanks between 4 and 40 pounds capacity, which helps to prevent propane leaks and potential explosions.
  5. Check the tank for any leaks if you smell propane. While the leak can simply be nothing more than residual from the valve, as additional security, you should check before you hook it up. A soapy "bubble test" is a simple yet effective test for leaks. Before the test, close the valve and insert the plastic plug. Make a heavy, soapy solution with dishwashing soap and pour enough over the regulator, valve and threads to coat. A leak will produce bubbles from the aperture. If you find a leak, call the supplier immediately. Do not transport the tank until you receive instructions from the supplier.

Things You Will Need

  • Propane tank "nanny"
  • Propane cylinder plug


  • Store propane tanks away from the grill or any heat source.
  • Do not store inside a residential dwelling such as a basement or garage.
  • If you plan to transport a propane tank to a supplier or filling station, make sure the trunk temperature is cooler than 120 degrees Fahrenheit.

About the Author

Merle Huerta, an adjunct instructor of English skills, began writing during her husband's combat deployment to Iraq in 2003. Her articles have appeared in "The Jerusalem Post," LiteraryMama.com and USA Travel Tips, among other publications. Huerta has an M.A. in instructional media and technology from Columbia University and is a graduate of CUNY's The Writers Institute.

Photo Credits