Abstract: A pumping device for processing a liquid comprises: a plurality of pistons, each of which is slidable along a movement direction in order to vary the volume of a corresponding chamber; a casing inside of which a driving device is housed for moving each piston of the plurality of pistons along the movement direction; a head inside of which the chambers are at least partially obtained; a plurality of suction valves, each one of which is associated with a chamber and is operable for enabling the liquid to enter the chamber; a plurality of delivery valves, each one of which is associated with a chamber and is operable for enabling the liquid to exit the chamber. Each suction valve has an axis arranged transversely with respect to a further axis of the delivery valve associated with the same chamber. The pumping device further comprises an intermediate body interposed between the casing and the head. The intermediate body is provided with a guide device for guiding each piston along the movement direction.