摘要 |
A three-port thermally responsive valve for alternately valving an intermediate fluid port with adjacent upper and lower fluid ports. A single valve member is movably contained within a housing fluid passageway and spring-biased in a first position so that a sealing surface at each end of the valve member is respectively engageable with and spaced from corresponding valve sealing surfaces in the fluid passageway. The sealing surfaces on the valve member are spaced with respect to the valve sealing surfaces in the housing fluid passageway to maintain isolation of the upper and lower fluid ports until valving of the intermediate fluid port with either the upper or lower fluid port is completed. When predetermined temperatures are encountered, a thermally responsive actuator connected to the valve member by a rod overcomes the biasing force generated by the spring and moves the valve member to the second valved position.
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