| 摘要 |
A Top Entry Trunnion Ball Valve is provided having a valve body forming seat recesses with seat members movable disposed therein and urged towards sealing engagement with a spherical valve member by spring members and by differential pressure induced force. A seat retractor mechanism is movably disposed within the valve body and is movable by an externally controlled tool into retracting engagement with the seat members. The seat members and the seat retractor element have cooperative cam surfaces that cause camming movement of the seat members away from the valve member upon linear movement of the seat retractor. A fire safe seal and spring chamber is in communication with a relief passage having volumetric closure plugs permitting introduction of solvent or other softening agent into the spring chambers for removal of any accumulation of foreign material therein.
|
