| abstract |
Two-stage volumetric pump for pumping liquefied petroleum gases in the liquid phase, which pump is of the type consisting of: two chambers (110, 210); a valve (120), communicating with the first chamber, for the admission of liquefied petroleum gas, to be pumped in the liquid phase; a valve (220), communicating with the second chamber, for the delivery of the pumped liquid; a transfer duct (310) uniting the two chambers and fitted with a valve (320) preventing the return of liquid from the second chamber to the first. n According to the invention, each chamber comprises a wall formed by a diaphragm (130, 230) freely deformable in such direction as to increase the volume of the chamber under the effect of the pressure of the liquid, and operably deformable in the opposite direction under the action of actuating means acting alternately on the diaphragms of both chambers. |