| 摘要 |
PURPOSE:To positively prevent high temperature fluid from leaking, by lowering the pressure of sealing gas to be supplied to high temperature fluid shut-off valves close to a contamination source than the pressure of sealing gas to be supplied to high temperature fluid shut-off valves away from the contamination source. CONSTITUTION:The high temperature fluid shut-off valves 5a, 5b, 5c, 5d through which sealing gas is supplied via each groove 24 are arranged in series in a pipe line in which high temperature fluid flows, and pressure-reducing valves 28, 29 are attached to pipe lines 32, 33 connected to a sealing gas supply apparatus, so that the pressure PS1 of the sealing gas to be supplied to the high temperature fluid shut-off valves 5a, 5d becomes lower than the pressure PS2 of the sealing gas to be supplied to the high temperature fluid shut-off valves 5b, 5c. Thus, as the sealing gas can leak from the upper and lower surfaces a valve seat 9 to a fluid path 7 located upstream and a fluid path 8 located downstream, the high temperature fluid in the fluid path 7 can be positively prevented from leaking into the fluid path 8. |
