GLOVE VALVE FOR HIGH TEMPERATURE

PROBLEM TO BE SOLVED: To prevent an excessive load from being applied on a valve element and a valve sat by the differential thermal expansion of a valve box and a valve rod, and prevent generation of leakage of the valve seat even when thermal expansion of the valve rod grows larger than that of the valve box. SOLUTION: In a valve device interposed on the way of a piping 2 for circulating high temperature gas, a valve box 5 which is formed as a double structure of an inner cylinder 3 for circulating high temperature gas and an outer cylinder 4 which is loosely fitted to the inner cylinder 3 is arranged, and a valve seat member 7 for forming a valve port 6 opposing to the one end opening of the inner cylinder 3 is arranged. A valve element 8 which is advanced/retracted in a direction faced forward of the opening of the inner cylinder 3 and for opening/closing the valve port 6, and valve rod 9 for opening/closing driving the valve element 8, are arranged in the inner cylinder 3, and a valve seat holding means 12 for, being freely advancing/retracting, holding the valve seat member 7 in a direction faced to forward of the opening port of the inner cylinder 3 and for sealing a space formed between the valve seat member 7 and the outer cylinder 4, is arranged on one end opening port of the outer cylinder 4.