| 摘要 |
<p>A fluid operable valve suitable for use in high temperature and pressure environments involving the flow of solids material, incorporates a main valve member and a pilot valve member co-operable with separate seats axially spaced apart in association with the inlet of the valve. The arrangement is such that in operation the pilot valve member is sequenced to close against its seat prior to the main valve member which is purged prior to closure by a gas to remove particles of material which might cause ineffective sealing.</p> |
