An air-driven pump includes a source of compressed air, a vacuum source including a venturi and two pump units with structurally independent pumping elements dividing pump chambers from air chambers. A directional control valve is in communication with the source of compressed air, the vacuum source, the pump unit air chambers. The directional control valve includes two valve positions alternating communication of the source of compressed air and the vacuum source with the air chambers. A pilot valve system shifts the directional control valve between the two valve positions at end of stroke positions of the pump and includes actuators extending into the air chambers to engage the pumping elements with the air chambers contracted.

An air-driven pump includes a source of compressed air, a vacuum source including a venturi and two pump units with structurally independent pumping elements dividing pump chambers from air chambers. A directional control valve is in communication with the source of compressed air, the vacuum source, the pump unit air chambers. The directional control valve includes two valve positions alternating communication of the source of compressed air and the vacuum source with the air chambers. A pilot valve system shifts the directional control valve between the two valve positions at end of stroke positions of the pump and includes actuators extending into the air chambers to engage the pumping elements with the air chambers contracted.

A fuel supply system for a vehicle uses a seal-less piston LPG injunction pump which pumps fluid from a storage tank to an engine. The pump uses the vehicle's pneumatic air system, wherein the pressurized air of this system alternatingly drives an actuator magnetically coupled to a piston.

A first diaphragm which forms a wall of a first pump chamber is provided in the double diaphragm pump according to the invention, wherein the first diaphragm can be moved by means of a first driving means. In addition, a second diaphragm which forms a wall of a second pump chamber is provided, wherein the second diaphragm can be moved by means of a second driving means. What is more, a control for the driving means is provided, said control being designed and operable such that it controls the two driving means subject to one or a plurality of conditions.

A first diaphragm which forms a wall of a first pump chamber is provided in the double diaphragm pump according to the invention, wherein the first diaphragm can be moved by means of a first driving means. In addition, a second diaphragm which forms a wall of a second pump chamber is provided, wherein the second diaphragm can be moved by means of a second driving means. What is more, a control for the driving means is provided, said control being designed and operable such that it controls the two driving means subject to one or a plurality of conditions.

An industrial pneumatic pump for a viscous fluid includes a pump body, a pneumatic cylinder, a piston separating first and second chambers, a pump shaft integral with the piston and sliding in a channel, a pressure chamber with inlet and outlet ports for compressed air, and suction and outlet mouths for the viscous fluid. The pump also includes: a connection chamber connected to the chambers, and to the channel; a distributor including a spool connecting the chambers to an air discharge hole and the air outlet port; opposed first and a second pistons acting on the spool, sliding in a first and a second service chamber connected to the channel by ports, the spool including a thickening cooperating with the outlet port to cause a pressure perturbation in the service chambers causing the immediate displacement of the piston to act on the spool.