Abstract: The invention relates to a process of heat transformation to convert the low-temperature waste heat from cooling circuits of block-type thermal power station (BTPS) reciprocating-piston combustion engines into steam or other heating media of a temperature required for operation by adopting the principle of the high-temperature heat pump according to which the low-temperature heat produced by recooling the engine cooling circuits to their required inflow temperature required by construction is transferred to a liquid working medium, is absorbed by the working media vapors by partial evaporation, and is brought, by compressing and condensing the working medium vapors, to the temperature of the in-plant heating media and is transferred to them.

Abstract: A double seat valve has two serially arranged closure members that are movable with respect to each other, that prevent in the closed position of the valve fluids from overflowing from one part (1a) into another part (1b) of the valve housing and that delimit both in the closed and in the open position of the valve a leakage cavity (3). The valve rods (5a, 6a) for the closure members (5, 6) are concentrically arranged inside each other and unilaterally extend out of one part of the valve housing into the surroundings of the valve. The disclosed double seat valve satisfies the requirement for a leakage cavity that can not be drained, but also pressure-relieved in all imaginable operating conditions.

Abstract: A process is disclosed for switching without leaks a double seat valve comprising radial sealing elements shaped in a slide-shaped closure member (3). In order to ensure leakfree switching, in a first embodiment of the process, radial sealing elements (1, 1*) are guided and remain sealed in a cylindrical valve seat surface (5) while the valve is opened. Sealing elements (2, 2*) provided in a second closure member (4) sealingly engage an end section (E) of the radial sealing elements (1, 1*) and the end section (E) is sealing surrounded by the sealing means (2) when the valve is further opened and when it reaches its open position.