Abstract: A structure for the end of pressure vessels, most applicably plate heat exchangers, for reducing the effects of movement changes and vibrations caused by variations in internal pressure and temperature. The end is made up of a heat transfer plate and an end part in such a way that the end part is connected by welding to the shell of the outer surface of the heat exchanger stack, forming an enclosed chamber on the end of the heat exchanger, into which chamber higher pressure than the external pressure level is brought and/or generated. The higher pressure receives and dampens, via a heat transfer plate, vibration and pressure shocks harmful to the heat exchanger structure in the medium circuits of the heat exchanger.

Abstract: A structure for the end of pressure vessels, most applicably plate heat exchangers, for reducing the effects of movement changes and vibrations caused by variations in internal pressure and temperature. The end is made up of a heat transfer plate and an end part in such a way that the end part is connected by welding to the shell of the outer surface of the heat exchanger stack, forming an enclosed chamber on the end of the heat exchanger, into which chamber higher pressure than the external pressure level is brought and/or generated. The higher pressure receives and dampens, via a heat transfer plate, vibration and pressure shocks harmful to the heat exchanger structure in the medium circuits of the heat exchanger.

Abstract: The invention concerns a method of constructing a heat exchanger as well as a heat exchanger constructed in accordance with said method. The method comprises piling of essentially similar corrugated thermal transmission plates to cover each other and connecting the spaces between the plates from their edges to inlet and outlet conduits for the mediums participating in thermal transmission so that through every second space between the plates is passed a flow of heat giving medium and through every second space between the plates a flow of heat receiving medium. Essential to the present invention is that the pressure losses of flows and the thermal transmission coefficient of the exchanger are established by piling the thermal transmission plates one over another so that the grooves in different plates are placed at a selected angle with each other.

Abstract: An hydraulically operated striking apparatus for driving a rock drill or the like comprises a body having an axial, generally cylindrical, interior space with an inwardly protruding annular member. A cylindrical piston is positioned in the space in sliding contact with the protruding annular member, and the piston has canal means in its outer surface. The body, the annular member and the piston define two annular spaces and an annular distributing valve is slidably disposed within one of the spaces. The two spaces communicate with each other by means of the piston canal when the piston is in a first slidable position, and the protruding annular member prevents communication between the two spaces when the piston is in a second slidable position. The piston is provided with an axially disposed extension which, in combination with an outlet means, serves to permit a third, annular axial space to communicate with either an inlet means or an outlet means at all times.