A hose connector assembly for connecting a hose to a port of a pressurized fluid system, the system including a socket and an adapter tube in fluid communication, with an end portion of the socket adapted to be connected to a port and having a receiving opening. The adapter tube has a plug-in end portion to be pushed into the receiving opening which is adapted to cooperate with the plug-in end portion to form a plug-in connection mechanism. The adapter tube has a hose connector end fitting adapted to be received in, hold and retain a hose end portion. Complementary locking surfaces of the receiving opening and plug-in end portion are engaged when the plug-in end portion is connected by the plug-in connection mechanism to the socket to lock the adapter tube with respect to the socket against rotation about the longitudinal axis of the adapter tube within the socket.