Industrial technique

Claim 1

In combination with a pressure vessel wall having at least one bore extending therethrough, a penetration device fitted into the bore, the device comprising an inner tubular member defining a fluid flow passageway through the bore, an outer tubular member concentrically spaced about the inner member and forming therebetween a first annular cavity extending at least the length of the bore, thermal insulating material disposed within the cavity, the inner and outer members having adjacent ends seal weld-united outside of the bore, the outer member having its other end seal welded to a vessel section longitudinally extending within the bore and terminating intermediate the ends of the bore, and portions of the outer member and vessel section being radially spaced from the bore to form therebetween a second annular cavity extending to the outer surface of the vessel wall, the bore being formed with a circumferential enlarged recess along an inner end portion of the second cavity, the recess and second cavity cooperating with one another to define an annular chamber facing the seal weld junction between the outer member and vessel section, and wherein the chamber provides access for non-destructive inspection of said seal weld junction.