No, probably just a cast-iron, hub-end reducer. Or maybe just a straight coupling -- can't tell from this angle. Used to connect the two different sizes of pipe.
A check valve would typically have a different look with a bulge and an access cover plate.
A hub-end fitting is one what the pipe is cocked into the end bell. This cocking was an old form of connecting the pipe that is normally not used anymore.
I may post more this evening with catalog illustrations.
Brian Norden
Edited 2 time(s). Last edit at 05/29/2018 08:07AM by Brian Norden.