Abstract: A device for conveying and/or distributing fluids comprises a housing with connection portions, one or more threaded ring nuts which can be screwed to the connection portions for joining them, and a tightening seat formed in the housing. The device further comprises a first adapter with a portion for coupling with the tightening seat, a driving portion for engagement with an engagement portion of the ring nut and a first key seat shaped to receive a portion for coupling a tightening tool.