Liquid filled flexible sealing joint

Abstract

A flexible joint assembly for interconnecting two conduits that transport fluid under pressure includes an annular housing and a tubular member of smaller diameter than the housing. The housing has an opening at each end, as well as two spaced apart, annular flanges that extend radially inwardly with respect to the housing. The tubular member has adjacent one end a flange which extends radially outwardly and which is disposed between the two flanges of the housing. The other end of the tubular member projects from an opening at one end of the housing for attachment to a fluid conduit. Between each housing flange and the flange of the tubular member is an annular flexible element that includes at least one body of elastomer. One side of one of the flexible elements is exposed to the pressurized fluid flowing through the conduits and the joint, while one side of the other flexible element is exposed to the exterior of the joint. Between the other sides of the two flexible elements and within the housing, there is an annular cavity separate from the fluid flow path through the joint. The cavity is fluid tight and is filled with a quantity of substantially incompressible liquid. The liquid in the cavity serves to transmit pressure between the two flexible elements so that the elements act in series to share loads resulting from the difference between the external ambient pressure on the joint and the pressure on the fluid in the joint. The overall construction of the joint thus reduces the pressure on each flexible element and can provide both a primary and a backup sealing mechanism for containing pressurized fluid within the joint.