Abstract: A welding device for welding a welding profile to an inner welding groove of a locking device, consisting of a first hollow profiled member inserted into a second hollow profile member, has a carriage with a housing whereby the carriage has a longitudinal axis and is movable in the longitudinal direction. A heating device is connected inside the housing. A pressing device for pressing the welding profile into the welding groove is connected inside the housing. The pressing device has a pressure-applying member. A clamping device for securing a lower flattened side of the welding profile is connected inside the housing. In the direction of supplying the welding profile the clamping device is arranged downstream of the heating device and the pressing device. The welding profile is guided from the heating device via the pressure-applying member to the clamping device.

Abstract: A method for connecting in a liquid-tight manner cooperating lock halves of a locking device of adjacent wall sections of a multi-sectioned wall introduced into a suspension includes providing a first lock half as an inner profiled member and a second lock half as an outer profiled member. The inner profiled member is inserted into the outer profiled member so that the profiled members substantially areally rest at one another and form a capillary gap. An inner groove is cut over the length of the lock halves such that the inner groove extends through the wall of the inner profiled member into the wall of the outer profiled member. The area of the wall of the inner profiled member where the inner groove is located is sealed against the suspension with a sealing material introduced into the gap. The inner and outer profiled members are fused with a fusing material introduced into the inner groove.