We offer two different styles of Increasers for Rock-Vent Pellet Pipe system. Choose between a 3" Stove to 4" Pellet Vent Pipe Increaser or 3" Pellet Vent Pipe to 4" Pellet Vent Pipe Increaser. Fabricated with 304L stainless steel inner and galvalume outer with painted black finish. Stove to Pellet Vent vs. Pellet Vent to Pellet Vent Increasers The 3" Stove to 4" Pellet Vent Increaser is used when connecting a pellet stove with a 3" exhaust to our 4" pellet vent pipe. Some stoves have a 3" exhaust outlet, however the manufacturer of the stove might require a 4" diameter pellet vent pipe if the finished chimney height is above a certain height. The 3" end will be male and the 4 inch end will be a female end to accept our pellet vent pipe. Simply put, this is used from a 3" pellet stove exhaust to our 4" pellet vent pipe. The 3" to 4" pellet vent Increaser is used when the 3" pellet vent pipe needs to increase to 4" pellet vent pipe. The 3" end is male and the 4" end is female. This can be used to make the transition from 3" to 4" at the ceiling or wall as opposed to at the stove. Simply put, this is used from our 3" pellet vent pipe to 4" pellet vent pipe. Note: If you have a Harman Pellet Stove, you will need the Harman Pellet Stove Increaser (see below). Measurement Charts: 3" to 4" Pellet Vent Increaser 3" to 4" Pellet Vent Increaser A 3.5” B 4.5” C 4.88” *Due to many variables beyond our control, the installer should check actual parts for final dimensions. 3" Pellet Stove to 4" Pellet Vent Increaser 3" Pellet Stove to 4" Pellet Vent Increaser A 3.09” B 4.75” C 4.57” *Due to many variables beyond our control, the installer should check actual parts for final dimensions.
