[en] The results of an experimental investigation of nucleate boiling under various conditions, including: I - with forced flow in a vertical tube, II - with natural circulation in a vertical tube, III - in a pool on a technical surface, IV - in a pool on the inner surface of a tube (on a fragment of a cut tube) are presented. A weaker dependence of α on q and p with channel boiling compared with pool boiling on a technical surface has been observed. It is shown that generally boiling curve IV does not coincide with the one either for conditions I - II or for conditions III. The analysis of some possible factors influence on the position of the boiling curves is conducted. A correlation for nucleate boiling heat transfer of cryogenic fluids in industrial tubes under conditions of both natural and forced circulation is recommended