The boss adaptor is solvent welded into the circular opening in a boss fitting. The waste pipe is then glued inside the boss pipe to give a permanent fit.
This solvent weld boss adaptor is used in conjunction with either an SP583 Short Boss Pipe, an SP581 boss pipe or an SP319 strap boss to connect a waste pipe into a 110mm soil pipe. It can also be used inside the boss shoulders of other fittings such as junctions.