Abstract: The invention relates to a grate for supporting tube plates for assembling in a steam generator or the like. The grate is characterized in that the ends of the plates forming the grating penetrate into and are received, at least partially, without any longitudinal gap or clearance in grooves in the frame body, which frame is preferably formed by three rings, at least partially superimposed, of which the intermediate ring has said grooves, while the other two upper and lower rings are secured to said intermediate ring and enclose therebetween the ends of the individual plates threaded in the grooves of the intermediate ring; a diametrical stiffening device secured by welding is also provided. It is the object of the invention to provide an economical and efficient grate allowing to avoid welding of the plates to one another and between said plates and frame, while ensuring the greatest reliability.

Abstract: A supporting grid for pipes comprising a frame and a reticular structure made of different materials having different thermal expansions, wherein a manhole and associated cover are provided, wherein said cover is made with the same material as the reticular structure and is secured to it, and wherein one or more connections are provided between said cover and said frame for preventing only tangential movements relative to the frame, while one or more connections are provided for preventing only movements perpendicular to the grid surface, enabling all these connections free thermal expansion of said reticular structure and said cover relative to said frame.

Abstract: A method of manufacturing a grill-type support suitable to act as a support and tube spacing member for steam generators (particularly natural circulation steam generators for pressure water reactors), heat exchangers and the like, wherein the actual lattice of the grid comprises strips having a certain thermal expansion, whereas the frame is made of another material having different thermal expansion, and during assembling the outer frame is connected to the strips, so as to be fast therewith and remains so for all the time required for manufacture, transport and erection, whereas as soon as said generator is set to work said strips of different material can slide relative to said frame, so that, said frame while surrounding and supporting such strips, allows a different thermal expansion for said central strips and frame.