According to the invention, a releasable plug connection for inserting a nozzle tube (2) has a jack consisting of a hollow cylinder and a sleeve displaceably mounted on said cylinder. The nozzle tube (2) is provided with radially springloaded lugs (20), the free ends of which are in contact with a locking surface. The locking surface is formed on a flange of the sleeve which can slide relative to the hollow cylinder against the force of a spring. For releasing the connection, the sleeve is pushed back so that the lugs (20) slide along a truncated cone on the hollow cylinder and are pushed inwardly in the process. As a result, the ends of the lugs (20) slide from the locking surface. As soon as the lug ends have left the locking surface, the nozzle tube (2) shoots from the jack under the action of the spring.
