A device for introducing hot gas into a heating surface pipe of a waste heat boiler includes an outer pipe that is connected to the boiler wall, preferably to the bottom of the pipe. The device also includes an inner pipe or entry pipe that has an admission section that is cylindrical or conically narrows and also has a discharge section that is connected to the heating surface pipe. The inner pipe is connected to the outer pipe via a rounded reversible cap while forming an entry opening for the hot gas. The inner pipe is surrounded by the outer pipe at a distance. The device also includes a coolant guiding pipe, which is placed between the outer pipe and the inner pipe and which extends into the proximity of the reversible cap. The guiding pipe is provided in the form of a force-transmitting component and is connected, in a removable or fixed manner, both to the inner pipe as well as to the outer pipe each time with at least three connecting ribs which are uniformly distributed over the periphery and which are provided for introducing or transferring forces.