The valve of a steam trap is opened and closed by operation of a temperature sensitive bimetallic assembly having a stacked configuration with individual bimetallic members of the stacked assembly moving between a first and a second position in response to temperatures within the steam trap.Cast Steel Valves The bimetallic members are arranged to vary the length of the bimetallic stacked assembly to open and close the valve of the steam trap, with the length of the stack being, preferably, diminished in response to a higher level of temperature.Bellow Seal Valve A steam trap including a fluid inlet port, a fluid outlet port, valve means for controlling fluid flow through said steam trap from said inlet port to said outlet port and a bimetallic assembly responsive to temperature variations for controlling opening and closing of said valve means, REDUCING VALVES said bimetallic assembly comprising a plurality of bimetallic members having insert means separating each of said bimetallic members from a next adjacent bimetallic member, said bimetallic assembly being configured as an elongated stack with said bimetallic members arranged to vary the length of said stack by temperature responsive movement of each of said bimetallic members between a first position at a higher temperature and a second position at a lower temperature, said bimetallic members and said inserts being arranged to effect variation in the length of said stack when said bimetallic members move between said first and said second positions, and means interconnecting said bimetallic assembly with said valve means to open or close said valve means in response to movement of said bimetallic members between said first and said second positions, both said bimetallic members and said insert means comprising a generally annular curved configuration with said bimetallic members being configured with a convex side and a concave side and adapted to reverse said concave side and said convex side thereof when moving between said first and second positions, the curvature of said bimetallic members generally conforming to the curvature of said insert means when said bimetallic members are in one of said first and said second positions. Bimetallic valve control elements normally involve a pair of metallic plates having different coefficients of thermal expansion which will bend as a result of variation in temperatures. Such bimetallic control plates may exhibit disadvantages due to slow rates of bending variation and low sensitivity to temperature change. Furthermore, bimetallic control devices may be difficult to support within a steam trap inasmuch as large external forces may cause damage thereto. In conventional valve controls, a plurality of bimetallic plates may be arranged in such a manner that the variation in bending of all of the plates may be cumulatively applied in order to supplement a smaller or slower rate of bending variation in each of the individual bimetallic plates. In such an assembly, larger external forces involved in controlling the opening and closing of a valve may be better supported. Nevertheless, in such bimetallic valve control devices utilizing plural discs of bimetallic plates stacked in layers, it is still difficult to avoid problems because of the fact that such control members are subjected to forces arising upon opening and closing of a valve member and also fluid pressure forces acting thereon as well as other elastic forces. Thus, bimetallic control devices are always subjected to large external forces and, additionally, are exposed to ambient fluid pressures and temperatures which are rather high and which may adversely effect performance of the control. Therefore, the performance of bimetallic control devices may easily change and deteriorate because of electro-chemical erosion of the parts or because of cracking due to stress. Thus, the problem arises in that the steam trap involving bimetallic valve controls may not exhibit a uniform performance characteristic over an extended period of time but may require frequent adjustment. Furthermore, the operative life of such steam traps may be significantly shortened due to malfunction of the bimetallic valve controls.

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