| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively manufacture a gas cock that can reliably prevent gas leakage even when exposed to high temperature. SOLUTION: The gas cock comprises a valve casing 11 of metal, a ball- structure valve element 21 of metal disposed in the valve casing 11, seats 20 of resin for supporting the valve element 21 in a rotatable and sealed relation, a valve stem 23 of metal having one end connected to the valve element 21 and the other passed through and projected out from the valve casing 11 and capable of rotating the valve element 21, first annular packing 30 for forming a seal between the outer circumference of the valve stem 23 and the inner circumference of the valve casing 11 in the passing region of the valve stem 23, and second refractory packing 31 disposed between the outer circumference of the valve stem 23 and the inner circumference of the valve casing 11 in the passing region of the valve stem 23.
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