Abstract: A thermostatic steam trap for use in sanitary environments has a steam trap body defining a steam trap cavity and consisting of an inlet body portion defining an inlet port in communication with an inlet cavity portion and an outlet body portion defining an outlet port in communication with an outlet cavity portion. The inlet and outlet cavity portions are disposed in communication to define the steam trap cavity. A centering member is disposed generally between the inlet and outlet body portions. A thermostatic bellows/plug assembly mounted to the centering member moves within the steam trap cavity between a first position in engagement with a seat defined by the steam trap body, thereby to resist flow of fluid between the steam trap cavity and the outlet port, and a second position spaced from engagement with the seat, thereby to permit flow of fluid between the steam trap cavity and the outlet port.