Leak tests are legally required any time there is an interruption of service, meaning the flow of gas was stopped for any reason. It’s simply testing the integrity of the system plumbing joints following an interruption of service or out-of-gas situation. National Fire Protection Association guidelines (NFPA 54 2006, 8.2.3) state that “Immediately after the gas is turned on into a new system or into a system that has been initially restored after an interruption of service, the piping system shall be tested for leakage. If leakage is indicated, the gas supply shall be shut off until the necessary repairs have been made.”
This question is often asked following a delivery. Whether the propane tank is being filled partially or completely, the fixed liquid level gauge is always used during the delivery process. It is common for the delivery driver to write the ending percentage on the fuel ticket after the delivery, which is often 80% if the tank has been filled. Even if the face gauge reads 75% following delivery, the tank is at 80% because the fixed liquid level gauge indicates the actual propane liquid level (at 80%) in the tank, not the face gauge.
Consumers often feel that a tank leak results in the loss of many gallons of propane gas, but in reality, the loss is typically minimal.

First, please realize it is common to hear a gentle hissing/humming sound when an appliance is running. You should only be concerned if you smell gas (see next question below).

In terms of loss of propane, think about a helium tank filling a balloon and the loud hissing noise and force at which the helium comes out of the tank. Now think about your propane tank. A standard size party balloon holds a volume of roughly .5 cubic feet. Just one gallon of propane, which produces 36.39 cubic feet of vapor, will fill almost 73 standard-size party balloons. So if you believe your tank has leaked 10 gallons of propane, that would equate to roughly 728 standard size party balloons! The actual amount of propane lost in a leak is far less than what most consumers would imagine.

Bottom line: if you ever suspect a leak, contact MEC immediately!

Propane users should always be on alert for the smell of propane odor, especially around a gas appliance or tank. If you do smell gas in your home, camper, RV or other areas around any gas equipment, or if a gas alarm signals the presence of propane, you should immediately follow these suggestions:

  • Extinguish all smoking materials and any other open flames or sources of ignition. Everyone should vacate the building, vehicle or area.
  • Move away without using any electric switches, appliances, thermostats, or telephones.
  • Close the gas shutoff valve on the propane tank or cylinder.
  • Call MEC and/or your local fire department from a cellular telephone or a neighbor’s telephone.
  • Even if you do not continue to smell propane, do not open or turn on the propane supply valve and do not re-enter the building, vehicle or area. Let a qualified propane service technician check for escaped propane.
  • Have a properly trained propane service technician repair the leak. The propane service technician or emergency responder needs to determine that the leak situation has been fully resolved. The propane service technician will check all of your gas appliances and re-light any appliance pilots.
  • Return to the building, camper, RV or area only when the service or emergency technician indicates it is safe to do so.