GB679625A - Improvements in or relating to pressure vessels - Google Patents

Abstract

679,625. Joining pipes to headers BABCOCK & WILCOX, Ltd., and WEBB, T. B. June 7, 1950 [June 7, 1949], No. 15162/49. Class 99 (i). [Also in Group XXII] Each of a plurality of stub tubes is united to the wall of a pressure vessel by a fusion weld the root metal of which is removed, each of said stub tubes communicating with the interior of the vessel through an orifice formed in the metal of the vessel and of substantially smaller diameter than the bore of the stub tube. Preferably the pressure vessel serves as a distributer for distributing fluid under pressure to a bank of tubes e.g. in a heat exchange such as an economizer, boiler or superheater at least some of said tubes including a main part welded to one of the stub tubes, Fig. 1 (not shown). In Fig. 2 after the stub 21 has been fusion welded to the wall 3 of the pressure vessel (Fig. 2a) an axial bore 23 in the stub is extended and continued for a short distance into the vessel wall (Fig. 2b). Thereafter a hole 33 of smaller diameter than the bore 23 and constituting the orifice, is drilled through to the interior of the vessel. In Fig. 3 the stub is provided initially with a short spigot 43 which is located in a hole 45 in the vessel wall (Fig 3a). After welding, the bore of the stub is continued into the vessel wall (Fig. 3b), the boring operation resulting in the removal of the spigot. In Fig. 4, the stub is provided with a throughbore and with a short annular flange 57 which is fitted into a shallow recess 59 in the vessel wall (Fig. 4a). After welding, the stub bore is enlarged to remove the flange 57 and this bore is continued into the vessel wall (Fig. 4b), a hole 63 forming the orifice being drilled in the vessel wall either before or after the stub is welded to the vessel.