Form object of the found present a raccorderia for the mutual union of double tubes to two semi-cylindrical rooms or, and for the connection of such tubes with single tubes. It comprises : a connection for the splice of double tubes with first collarino of estate, having a two log of semicircular tube placed side by side in sol a piece one to the other by means of a ring-like and diametrical portion; a distribution cassette, to whose inside are at least two placed side by side canes, communicating with attacks threading for single tubes and double tube; a connection of conversion with attack threaded for double tube and a brace of threaded attacks, everyone for tube. Everyone of sayings attacks threaded for double tube has a struck inner ring of and is adjacent to a log of inner culvert that is equipped of septum for the splice with a double tube by means of an estate second collarino.