Apparatus and method for sealing a tube joint

摘要

A joint between a pair of coaxial tubes which extend into a pressure vessel from a surface is sealed using a sleeve-like housing which surrounds the joint to be sealed. An upper fluid-tight seal is formed between the longer of the tubes and the housing. A lower fluid-tight seal is formed between the housing and the surface. An intermediate seal is also formed between the housing and the shorter tube. The upper and lower seals are independently preloaded through the use of spring washers. Primary loading of the lower seal to the surface is caused by fluid pressure in the vessel which acts on the housing.