<p>The piece (111) has a tubular part connected with another tubular part of a fluid conducting line system. A circumferential guide surface (117) arranged behind another circumferential guide surface (122) with respect to an insertion opening of the piece. A circumferential recess (116) is located for a lip sealing (150) between the guide surfaces. Axial extensions of the guide surfaces represent quarter inner dimensions of the tubular parts. The piece is designed such that an inner mantle area of the tubular parts does not contact the piece in a connected condition. An independent claim is also included for an arrangement for distribution of cold water and hot water.</p>
