Flanges

The flange is the pavement fixing point for an elevated fixture, with the frangible coupling carrying the light above it; it mounts on an isolation transformer box or is anchored directly to the pavement. It comes in 8-inch and 12-inch sizes to suit the fixture: 8 inches is the smallest of the standard mounting diameters, while the 12-inch flange is used mainly for the elevated approach light range, though other elevated fixtures fit it too, and its wider bearing face spreads the side loads from a taller fixture. On impact the break occurs at the coupling above, leaving the flange and its anchorage in the pavement intact, so only the parts above it are replaced.