Prior to April 1, Florida's propane safety law required cylinders manufactured since September 1998 be equipped with the OPD. Older cylinders were exempt until now.
Consumers who are not sure if their cylinder has the OPD can check by looking at the valve on the tank. Old style valves have a round handwheel, but the newer OPD valves are triangular in shape and marked "OPD" on the valve body.
