History of Science and Engineering Annotation << Back HISTORICAL PRECONDITION OF APPEARANCE AND DEVELOPMENT OF A HYDRAULIC KEY AS AN IMPORTANT ELEMENT OF OIL TECHNOLOGICAL EQUIPMENT A.V. Yakhin, E.A. Udalova, D.V. Karetnikov, E.V. Popova The stages of the evolution of scientific thought and implementation techniques in the field of using the principles of hydraulic drive to create various machines and mechanisms are considered. The importance of hydraulic drive as one of the factors affecting scientific and technological progress and the development of world industrial production in the XVIII–XIX centuries is shown. Features of the development of design of hydraulic keys used in the construction and maintenance of oil equipment are presented, promising directions in the field of their improvement are formulated. Keywords: hydraulic key; hydraulic drive; hydraulics; hydraulic press; oil equipment; pipe connection. DOI: 10.25791/intstg.04.2020.1173 Pp. 40-44.