Oatey 43796 Gasket for Tapping into Cast Iron Soil Pipe For tapping into a 3"" or 4"" Sch. 40 DWV line. Saddle is solvent welded to the existing line and secured with metal V-bolts, washers and nuts provided in the kit. The tee accepts the incoming line inside the socket, or joins with a Sch. 40 DWV fitting. For tapping into a 3-Inch or 4-Inch Sch. 40 DWV line Saddle is solvent welded to the existing line and secured with metal V-bolts, washers and nuts provided in the kit The tee accepts the incoming line inside the socket, or joins with a Sch. 40 DWV fitting