| 摘要 |
<p>"FIRESAFE FLUID CONTROL VALVE" A valve member 17 when positioned so as to prevent fluid flow through a passage 11 in a valve body 10 engages a ring 14 made of flexible resilient fluorocarbon synthetic resin material, the ring 14 providing a fluidtight seal between the valve member 17 and a seat 12 on the body 10. In the event of the ring 14 failing, the valve member 17 engages a back-up ring 15 made of a high temperature, non-metallic material which is non-galling, such as graphite. The high temperature properties of the ring 15 thus enable the valve to remain fluid-tight when shut even if the flexible ring 14 is destroyed by fire. The ring 15 can be compressionformed in situ into a shape which ensures close contact with the valve member 17. In the event of the ring 15 also failing, the valve member 17 comes into contact with a metallic ring 13 from which it is normally spaced and thereby restricts the flow of fluid through the valve. This arrangement can be applied to butterfly-type valves(Figure 1) as well as to ball-type valves (Figure 4).</p> |
