The pipe joint includes a flare joint body 1F, a cap nut 2, and a stop ring 3. A curved pressure-contacting slope surface 32 of the stop ring 3 contacts a slope surface 5 with reduced-diameter tip of the flare joint body 1F under pressure to establish sealing by means of mutual contact between metallic surfaces. The pipe P is grasped in a tightly pressure-contacting state using a back tooth and a front tooth formed at a tip head 37 of a substantially cylindrical thin part 35 of the stop ring 3.

A fitting for connecting to a pipe, including a base body having at least one pipe section, a pressing section connected to the pipe section, and a functional unit connected to the pressing section. The functional unit includes a functional ring, a sealing element and a fixing element, wherein the functional ring, has an outer section arranged radially outside the pressing section and an inner section arranged inside the pressing section, and wherein the inner section positions the sealing element and the fixing element inside the pressing section. The fitting solves the technical problem of enabling easier and more reliable replacement of the functional parts. The invention also relates to a functional unit and a system.

A fitting for connecting to a pipe, including a base body having at least one pipe section, a pressing section connected to the pipe section, and a functional unit connected to the pressing section. The functional unit includes a functional ring, a sealing element and a fixing element, wherein the functional ring, has an outer section arranged radially outside the pressing section and an inner section arranged inside the pressing section, and wherein the inner section positions the sealing element and the fixing element inside the pressing section. The fitting solves the technical problem of enabling easier and more reliable replacement of the functional parts. The invention also relates to a functional unit and a system.