Check valve

A temperature responsive control system for a steam radiator having a radiator inlet and a radiator outlet and comprising:

• housing means comprising a union and defining a housing inlet and a housing outlet, said housing inlet connected for fluid communication with the radiator outlet;
• a valve body within said housing means and comprising an end wall, a side wall and a retaining ring portion that together define a valve chamber, said end wall defining a valve inlet opening providing communication between said housing inlet and said chamber and an annular valve seat within said chamber and encircling said valve inlet opening, and said side wall defining a valve outlet opening providing communication between said housing outlet and said chamber, said valve body further comprising an annular skirt portion extending outwardly from said side wall and retained by said union;
• a resilient, annular seal means disposed within said valve chamber and encircling said valve inlet opening;
• a bi-metalic disc within said valve chamber and having an outer peripheral portion retained by said retaining ring portion of said valve body, said disc being substantially parallel to said valve seat and normally spaced therefrom by a distance greater than the thickness of said annular seal means, and wherein said disc is adapted to respond to a predetermined ambient temperature within said valve chamber by deflecting concavely into said valve chamber and into fluid sealing engagement with one end of said annular seal means, an opposite end thereof being in fluid sealing engagement with said valve seat;
• and
• a thermostatically controlled steam trap connected to said housing outlet.