| 摘要 |
PURPOSE:To contrive to enhance sealing property, by a method wherein a valve seat having a smooth projection part is provided at an intermediate part between two knife edges provided in a radially spaced condition on a lower surface of a valve body. CONSTITUTION:The valve body 1 and the valve seat 2 are made of a stainless steel, and two knife edges 4, 5 are provided at mutually spaced positions on the lower side of the valve body 1. The valve seat 2 is provided with the smooth projection part 10 on its upper surface on the inner side with respect to the radial direction. Since a gasket 3 is made of a relatively softer metal, the projection part 10 closely engages with the gasket 3 even when the relative vertical spacing between the valve body 1 and the valve seat 2 is somewhat deviated. In addition, since the gasket 3 closely engages with the projection part 10, horizontal positioning for the time of starting the pressing of the valve body 1 against the valve seat 2 does not require strict precision. |
