It is called Airvalve, an extraordinary and revolutionary though simple idea, studied and created by Capalbo Lenin to eliminate the pressure in plumbing systems. But this is not its only advantage: in fact, its allows the elimination of the old air vent (that polluted the air) leading out of the roof through a chimney cap; thus reducing building time and cost, problems such as easement and pollution from noxious vapours from the drainage system. Airvalve, to be installed behind the lavatory or adapter under the roof or at the end of piping in parallel bathrooms, consist of a nonreturn valve that opens, by pressure or eddy, when water is flushed into the drainage system closing by the force of gravity when pressure ceases. The return of bad smells in thus avoided. Airvalve is important to professionals in the building and plumbing in the planning stage. This model, of universal usefulness, will be a contribution to healty living and deserves to be considered by Ministries of Health and Ecology, with its compulsory adaptation in all States