This waste reducer is used when a 32mm waste pipe is connected into a 40mm pipe, usually with the 32mm pipe dropping into the 40mm pipe below it running towards the soil pipe.
Waste tees are used in two different ways. Their main use is to connect a section of waste pipe into an existing pipe run. The tee is swept to ensure that the new section flows into the main run in the correct direction of flow. In most kitchen and bathroom applications the branch section drops into a main pipe run that is situated below it. The second use for a tee is to create a 90 degree bend with access for cleaning. This is achieved by using an access plug in the part of the swept tee that is at the opposite end to the direction of flow.