Abstract: A welding machine lays down its welding bead at the juncture of two surfaces, back of which a pressure boundary has been formed. A depression, or groove, is provided at the juncture of the two surfaces. The weld bead bridges over the groove to form a junction of the two surfaces, leaving the bottom of the groove above the pressure boundary to function as a passage for materials at the surfaces which vaporize at the temperature of the welding operation. The escape of the gases through the passage obviates the gases bubbling up through, and deteriorating, the solidifying weld material forming the junction.

Abstract: A tubular member of the type, primarily intended for utilization in a boiler, and having rifling, i.e., ribbing, provided on the internal surfaces thereof that is operable for purposes of effecting the disruption of the internal flow of the fluid passing therethrough. The ribbing with which the subject tubular member is provided embodies a configuration that is preselected so that the ribbing is operative to enable accurate and precise control to be exercised through the use thereof over the movement of the fluid flowing through the tubular member. Consideration is given to the following factors, among others, in establishing the design criteria that, in turn, determines the configuration that the ribbing embodies in a given tubular member; namely, the type of fluid; the fluid pressure; the fluid flow rate; the internal dimensions of the tubular member; the temperature gradient within the tubular member wall, both circumferentially and longitudinally, etc.