Abstract: Segments of a clad pressure vessel are welded together along seams at which the cladding is removed to expose a steel backing, so that initially a groove opens out of the cladding toward the interior of the vessel at each seam. Batten strips cover the grooves, and each of those strips has a depressed center portion which fits into the groove for that strip to center the strip along its groove. The batten strip also has flanges which extend outwardly from the depressed portion to overlie the cladding, to which they are welded along their edges. Cover plates are welded over the ends of batten strips. Thus, the cladding, the batten strips and the cover plates totally isolate the steel backing of the pressure vessel from the interior of the vessel, so that the contents of the vessel will not corrode the backing.

Abstract: A head for a pressure vessel has a contoured liner and successive wraps that overlie the liner and conform in contour to it. The liner has a machined outwardly presented surface, whereas the wrap immediately over it has a machined inwardly presented surface, and the liner and wrap are welded together with their opposed machined surfaces in face-to-face contact. The same holds true with the successive wraps so that two adjacent wraps are in face-to-face contact along their machined surfaces. A wrap may be heated prior to being placed over the liner or over another wrap so that upon cooling the wrap shrinks and places the underlying liner and wraps in a state of precompression. Both the liner and the various wraps may be formed from segments which are dished to the proper contour, then welded together into a rough liner or wrap, and finally machined along the appropriate surfaces. They may likewise be formed from single plates, forgings or castings.