For the soil vent and waste water drainage system of the building , it’s use the REDI’s fittings.
https://redi.eu/wp-content/uploads/2009/08/b-2.jpg400495redihttps://redi.eu/wp-content/uploads/2019/04/_aliaxis.pngredi2009-08-19 10:08:372017-06-13 14:51:51Bio –medical University Institute of Trigoria Rome