Connection devices for connecting a pipe having an outer peripheral projection, uses and installation method

A connection device (1) for connecting a pipe (100) having an outer peripheral projection (110) arranged in a longitudinal portion (120) thereof, the connection device (1) comprising:

• a connection part (10) with a receptacle (11) for inserting therein the longitudinal portion (120) of the pipe (100) with the outer peripheral projection (110),
• wherein the receptacle (11) has a central axis (13) which extends in an insertion direction (E),
• wherein the receptacle (11) is peripherally delimited by a peripheral wall (15) which extends around the central axis (13) and has a base surface (16.1) arranged transversely with respect to the central axis (13), in order to bring the outer peripheral projection (110) of the pipe (100) into contact therewith,
• wherein the receptacle (11) further has a radial recess (17) in a region of the base surface (16.1), which radial recess (17) is peripherally about the central axis (13),
• wherein the peripheral wall (15) comprises a conical portion (15.3) that tapers towards the base surface (16.1), and
• wherein the radial recess (17) extends radially further outwardly than an adjoining end of the conical portion (15.3);
• and
• a ring element (30) which is designed to be introduced into a gap (3) between the peripheral wall (15) of the receptacle (11) and the pipe (100) in the receptacle (11) in such a way that an axial end (31) of the ring element (30) presses against the outer peripheral projection (110) of the pipe (100), in order in this way to bring about a forming of the outer peripheral projection (110) with an inflow of forming material into the radial recess (17) of the receptacle (11).