| 摘要 |
PURPOSE:To obtain a temperature responsive valve having high durability by employing three element shape-memory alloy of nickel, titanium and copper as a drive source. CONSTITUTION:Three element shape-memory alloy of nickel, titanium and copper of such composition defined in a quadrilateral having first top point of 42atomic% of nickel, 52atomic% of titanium and 6atomic% of copper, second top point of 37atomic% of nickel, 52atomic% of titanium and 11atomic% of copper, third top point of 34atomic% of nickel, 50atomic% of titanium and 16atomic% of copper and fourth top point of 44atomic% of nickel, 50atomic% of titanium and 6atomic% of copper is employed for temperature sensitive element to form a spring which is combined with a bias spring 13 to constitute a drive source where the valve head 9 is moved up and down through tempera ture sensing thus to drain automatically. When compared with conventional temperature sensitive valve employing two element alloy of nickel and titanium, shearing stress will never drop through repeated load even when subjected to high steam pressure continuously thus to maintain constant load valve closing force.
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