| 摘要 |
<p>HIGH PRESSURE VALVE A valve comprising a housing with an inlet and outlet and a chamber in between, a reciprocating gate mounted in a gate seat disposed within the chamber for opening and closing the valve, an upper bonnet for closing the chamber at one end and a lower bonnet for closing the chamber at the other end, the gate being disposed between upper and lower stems which extend into the upper and lower bonnets respectively. Metal-to-metal seals are provided at all junctures between the above members in the lower gate position with back-up seals at the junctures of all moving members. A double edged seal ring integral with the upper stem self-contained within the upper bonnet provides a metalto-metal seal with the upper bonnet in the upper and lower gate positions of the valve. A metal gasket arrangement is provided between the upper bonnet and valve body whereby the assemblage of all points of contact between the gasket and body form an annular ring. A combination seal ring of metal and plastic is disposed between the gate seat and valve body at the outlet whereby the metal prevents the plastic from extruding between the seat and body and into the outlet. A removable backseat may be used to simultaneously seal the upper bonnet and upper stem upon moving the valve to one of its positions.</p> |
