Patent ID: 6341762
Filing Date: 2002-01-29
Classification: B64G,F16K,Y10S,Y10T

Abstract:
A service valve, comprising:an integrally formed valve body which comprises an at least generally longitudinally extending valve body bore, wherein said valve body bore comprises first and second ends which are longitudinally spaced, and wherein said valve body being integrally formed means that said valve body is formed from a single piece of material such that said valve body is free of any joint, wherein said valve body further comprises an inner wall which defines said at least generally longitudinally extending valve body bore, wherein said inner wall comprises first, second, and third wall sections which each have a longitudinal extent, wherein said second wall section is disposed longitudinally between said first and third wall sections, wherein a diameter of said valve body bore within said second wall section is different from a diameter of said valve body bore within said third wall section; an at least generally longitudinally extending valve stem which is slidably disposed within said valve body bore and which comprises a valve stem bore; a first leakpath defined between said valve body and said valve stem; and a plurality of longitudinally-spaced radial seals disposed between and engaging each of said valve body and said valve stem and which block said first leakpath at a plurality of longitudinally-spaced locations, wherein said valve stem is movable between at least first and second positions, wherein when said valve stem is in said first position, a first, second, and third radial seal of said plurality of longitudinally-spaced radial seals block said first leakpath at said first, second, and third radial seals by engaging said first, second, and third wall sections, respectively, such that said first end of said valve body bore is at least substantially isolated from said valve stem bore, and wherein when said valve stem is in said second position, said first radial seal is disengaged from said first wall section to allow flow through said first leakpath past said first radial seal such that said first end of said valve body bore is fluidly interconnected with said valve stem bore while said second and third radial seals each continue to block said first leakpath at said second and third radial seals by continuing to engage said second and third wall sections, respectively.