Abstract: A core (1) for producing castings (100) in a modular mold; each casting (100) having at least one thermally activatable portion (102) shaped so that it can face a heat source (HS); each casting (100) having at least one duct (106) contained inside the portion (102); the duct (106) being fluid tight so that a fluid can flow through it; the core (1) having a suitable shape to form, in negative, the duct (106); the core (1) including at least one insert (20)(20?)(20?) shaped so as to define at least two passages (200)(200?) for the fluid inside the duct (106).

Abstract: The invention relates to an arrangement in a pipe handling system, especially for handling pipes (4P) in connection with a derrick 1A, wherein the arrangement comprises a tower (1) and two preferably individually controlled operating arms (2a, 2b). The pipe handling system operates favorably in connection with a finger board (4) in which all fingers (4a, 4n) are pointing towards the center of the pipe handling system and especially towards a disc-shaped locking unit (4R) mounted on the top of the tower (1), and in connection with a side-step retraction system designed for use with a top drive drilling system.