| 摘要 |
PURPOSE:To reduce the number of valves in a pipeline system by disposing the first valve body and the second valve body opposite to a valve seat for sectioning a fluid passage into the upstream side and the downstream side. CONSTITUTION:The second valve body 8' is disposed below a valve seat 3. The second valve body 8' is arranged opposite to the first valve body 8 mounted above the valve seat 3 through the valve seat 3. The second valve body 8' is fixed to the forward end portion of a valve rod 10' of the second open-and-close mechanism 9' disposed below a valve box 1. In this arrangement, even if the first valve body 8 is damaged, the second valve body 8' may be closely adhered to the valve seat 3 to intercept a flow of a fluid. Therefore, it is not necessary to provide an open-and-close valve for a thorough overhaul on the upstream side of an automatic open-and-close valve. |
