Abstract: A thermostatic valve such as a steam trap, incorporates a cup shaped trap repair cartridge having the lower end of an annular intermediate valve body of cast metal threaded into an upwardly open, internally threaded cup shaped valve casing. The trap repair cartridge in turn receives the external threads of an inverted cup shaped cover of cast metal whose lower annular wall has threads on its outer periphery matching the internal threads of the annular intermediate valve body. The trap repair cartridge includes a conical bottom wall terminating in a flat, central horizontal bottom wall portion which is provided with an axial hole defining a valve seat. A hollow sheet metal thermostatic actuator is provided with an axial projection on one surface which projection is threaded about its outer periphery and which projection is threaded into a mating tapped hole within the bottom of an adaptor post.