Rotationally symmetrical water drain which can be inserted in a floor opening and comprises: - a drain pipe having a socket, - a drain cup, which terminates with a connector which opens out into the drain pipe, - a ring element, which is provided with suspension lugs and is intended for fitting on the floor opening and for accommodating the drain cup, - wherein the ring element has a cylindrical wall, which is arranged coaxially in relation to the axial orientation, and an inner collar, which is located perpendicularly to the axial orientation, - and at least one fire-protection element, which is installed in the water drain and is produced from a fire-protection compound which can be made to expand under the action of heat, - wherein a plug-in sleeve is inserted into the ring element, - the fire-protection element is placed between the plug-in sleeve, in the region of the cylindrical wall of the ring element, and the drain pipe, and - the inner collar has an internal diameter which corresponds to an external diameter of the socket of the drain pipe, or slightly exceeds the external diameter, and therefore the fire-protection compound, which can be made to expand under the action of heat, - is supported against an inner surface of the plug-in sleeve and subsequently the cylindrical wall of the ring element and also - the inner collar of the ring element, and - the fire-protection compound expands in the direction of the drain pipe and towards a base of the drain cup, characterized in that - the plug-in sleeve is inserted into the ring element such that it is supported on the inner collar and on an inner surface of the cylindrical wall, and - the fire-protection element is segmented. - a drain pipe having a socket, - a drain cup, which terminates with a connector which opens out into the drain pipe, - a ring element, which is provided with suspension lugs and is intended for fitting on the floor opening and for accommodating the drain cup, - wherein the ring element has a cylindrical wall, which is arranged coaxially in relation to the axial orientation, and an inner collar, which is located perpendicularly to the axial orientation, - and at least one fire-protection element, which is installed in the water drain and is produced from a fire-protection compound which can be made to expand under the action of heat, - wherein a plug-in sleeve is inserted into the ring element, - the fire-protection element is placed between the plug-in sleeve, in the region of the cylindrical wall of the ring element, and the drain pipe, and - the inner collar has an internal diameter which corresponds to an external diameter of the socket of the drain pipe, or slightly exceeds the external diameter, - is supported against an inner surface of the plug-in sleeve and subsequently the cylindrical wall of the ring element and also - the inner collar of the ring element, and - the fire-protection compound expands in the direction of the drain pipe and towards a base of the drain cup, - the plug-in sleeve is inserted into the ring element such that it is supported on the inner collar and on an inner surface of the cylindrical wall, and - the fire-protection element is segmented.