Abstract: This heavy duty equipment comprises a working cylinder, a striking piston, an upper lid and a holder of a drill bit. An anterior side duct in the wall of an upper working space of the working cylinder, communicating via an upper filling duct and a posterior side duct with a storage space provided in the upper lid, and an anterior bypass duct communicating via an axial duct in an axial pin and a posterior bypass duct with the storage space, axially define in the upper working space of the working cylinder, a compression space confined by the inner wall of the working cylinder, and further by an anterior face of the upper lid and by the external surface of the axial pin. The upper lid together with the axial pin and the in-built storage space form an assembly group in which a water valve is received.