Lubricated valve

A valve, comprising a body having a flowway therethrough, a closure member movable within the body for opening and closing the flowway, said flowway having an inner recess on one side of the closure member, an annular seat within the flowway recess, said seat comprising an annular body having enlarged and reduced diameter portions, the enlarged diameter portion of the seat body and a wall of the recess forming a first annular space between them, and the reduced diameter portion of the seat body and the wall of the recess forming a second annular space between them, said enlarged diameter portion having a first outwardly facing shoulder at the inner end of the first space, and said flowway recess having a second inwardly facing shoulder at the outer end of the second space, a first seal ring within the first annular space, a second seal ring within the second annular space, so as to define a lubricant chamber between the wall of the recess and the seat body intermediate the first and second seal rings, and means including at least one washer type spring arranged within the lubricant chamber and acting between the first and second seal rings for preloading the first seal ring against the first shoulder and into sealing engagement with said enlarged diameter portion and the wall of the recess, and the second seal ring against the second shoulder and into sealing engagement with said reduced diameter portion and the wall of the recess, said seat body having an annular groove in its inner end and a passageway connecting the groove with the lubricant chamber intermediate the first and second seal rings, said valve body having a passageway connecting its exterior with the lubricant chamber intermediate the first and second seal rings, and each said spring having a bypass therein fluidly connecting the lubricant chamber on its outer side with the lubricant chamber on its inner side.

A valve, comprising a body having a flowway therethrough, a closure member movable within the body for opening and closing the flowway, said flowway having an inner recess on one side of the closure member, an annular seat within the flowway recess, said seat comprising an annular body having enlarged and reduced diameter portions, said enlarged diameter portion of the seat body having an outwardly facing shoulder thereabout, a first seal ring of heat destructible material between the enlarged diameter portion of the seat body and a wall of the flowway recess, a second seal ring between the reduced diameter portion of the seat body and the wall of the flowway recess, so as to define a lubricant chamber between the valve body and the seat body intermediate the first and second seal rings, a backup ring on the outer end of the first seal ring, and means including at least one washer type spring arranged within the lubricant chamber and acting between the valve body and the backup ring for preloading the backup ring against the first seal ring and thus the first seal ring against the shoulder for sealing between said enlarged diameter portion and the wall of the flowway recess, said backup ring being movable by the washer type spring against the shoulder and into sealing engagement between said enlarged diameter portion of the seat body and the wall of the flowway recess in the event of destruction of said first seal ring, said seat body having an annular groove in its inner end and a passageway connecting the groove with the lubricant chamber intermediate the first and second seal rings, and said spring having a bypass therein fluidly connecting the lubricant chamber on its outer side with the lubricant chamber on its inner side.