Abstract: A vapor pressure pump for delivering a liquid into a system operating at a higher pressure or located at a higher level by action of a vapor pressure produced from a portion of the liquid to be delivered. The pump comprises a closed reservoir for liquid, which includes an unidirectional liquid inlet, an unidirectional liquid outlet, a vapor exhaust valve adapted to balance the pressure between the unidirectional liquid inlet and the reservoir during its filling. The pump also comprises a vapor generator for producing vapor inside the reservoir at a pressure sufficient to force out the liquid contained therein through the liquid outlet, and a control device for operating the vapor generator only when the liquid fed by the liquid inlet has reached a predetermined level in the reservoir.

Abstract: In a system of production, distribution and utilization of condensable vapor with recovery of the condensates in a closed container, a method for forced delivery of condensates consisting in awaiting the obtention of a predetermined level of filling of the container, in isolating from the outside the upper space of the container and in applying at the free surface of the contained liquid a sufficient additional vapor pressure to allow the total available gas pressure to be substantially equivalent to the sum of the necessary net geometrical height of delivery and the down-stream flow pressure losses to be overcome.