Patent ID: 6776392
Filing Date: 2004-08-17
Classification: F16K

Abstract:
A retractable plug assembly for engaging a seat ring having a seat ring top face and a seat ring seating surface, the retractable plug assembly comprising:a hollow plug housing; a plug body slidably disposed within the plug housing and defining a plug body seating surface which is complementary to the seat ring seating surface; a retainer ring disposed about the plug body and fixedly engaged to and extending below the plug housing; a wear ring fixedly disposed about the retainer ring below the plug housing and extending downwardly therefrom to define a wear ring bottom face, the wear ring bottom face being positioned at a level below that of the plug body seating surface; a spring retainer slidably disposed within the plug housing and fixedly engaged to the plug body; and a valve spring captured between the spring retainer and the plug housing, the valve spring being configured to bias the plug body away from the seat ring during initial engagement of the wear ring bottom face to the seat ring top face such that radially inwardly flowing fluid is prevented from directly impinging the plug body seating surface, the valve spring being further configured to resiliently deform during axially downward movement of the plug body such that the plug body seating surface may thereafter directly engage the seat ring seating surface to create a fluid-tight seal therebetween.