A regular elbow has a hub connection (or a copper pipe receiver) where the elbow actually fits over the copper pipe on both ends. A street elbow (or street ell) has the standard elbow connection on one side but a street connection on the other. A street connection is a sweat connection that is the same size as the copper pipe and does not overlap.
Copper fittings including 45 street ells and 45 elbows can be found at www.supplyhouse.com
