In order to increase safety for consumers, the National Fire Protection Association (NFPA) mandates that all tanks manufactured after Sept. 30, 1998 and all tanks refilled after April 1, 2002 must be equipped with an OPD valve. However, each state is responsible for enacting a law adopting the tank refill requirement.
Earlier this year, Massachusetts and Maine made it illegal to have a propane tank without an OPD valve. Connecticut, New Hampshire, Rhode Island and Vermont are expected to adopt similar laws requiring the safety valve.
"The overfill valve is a quick and inexpensive way to increase safety for summer grilling," says Jim Hurley, president of the Propane Gas Association of New England. "We're finding that many gas grill owners are unaware of the new requirement that, as of April 1, the safety valve is required for all propane cylinders ranging from four to 40 pounds."
The bottom line, says Hurly, is that in the states where laws have been adopted, consumers won't be able to refill old cylinders unless their propane tanks have the valve in place. The price for a new tank equipped with the valve ranges from approximately $25 to $35.
Overfilling a tank leaves no room for the liquid propane to expand, increasing the risk of accidents. The valve increases safety by using a float mechanism, which stops the filling process when the tank is 80 percent full.
Tanks with the device already installed have a triangular valve handle with the letters "OPD." Tanks without the valve have a handle shaped like a star or wheel. Tanks without an OPD can be used until they are empty, but they cannot be refilled without the valve.