Abstract: A pump arrangement comprising two pump units, each pump unit comprising a pumping cylinder, a reciprocally movable pumping piston, said pumping piston delimiting a pumping chamber in the pumping cylinder in communication with a pump port for fluids, an actuator connected to the pumping piston, and determining a value dependent on the position of the pumping piston in the pumping cylinder, said pump arrangement further comprises a inlet and delivery valves connecting the pump port of each pump unit to a source line and a delivery line for pumped fluids, wherein the pump arrangement comprises at least one regulating unit the flow of the pumped fluids based on the value dependent on the positions of the pumping pistons in the pump units. Also a system comprising such a pump arrangement and a method for pumping fluids in said pump arrangement.

Abstract: The present invention relates to a pump arrangement comprising two pump units, each pump unit comprising a pumping cylinder, a reciprocally movable pumping piston, said pumping piston delimiting a pumping chamber in the pumping cylinder in communication with a pump port for fluids, an actuator connected to the pumping piston, and means for determining a value dependent on the position of the pumping piston in the pumping cylinder, said pump arrangement further comprises a first set of valves connecting the pump port of each pump unit to a source line and a delivery line for pumped fluids, wherein the pump arrangement comprises means for regulating the flow of the pumped fluids based on the value dependent on the positions of the pumping pistons in the pump units. The present invention further relates to a system comprising such a pump arrangement and a method for pumping fluids in said pump arrangement.

Abstract: A constant flow regulator device for maintaining a constant flow of fluid when a variable fluid pressure is applied, comprising an inlet duct (506) for incoming fluid, a housing (500), and a movable partition (502) facing the inlet duct and being subjected to an elastic force. A fluid passage (510) of variable cross section area is formed between the inlet duct and the movable partition. The housing and movable partition form an inner compartment (504) in fluid communication with the inlet duct for establishing a fluid pressure inside the inner compartment approximately equal to the fluid pressure in the inlet duct. The size of the movable partition is significantly greater than the size of the inlet duct such that, in use, the partition is moved towards the inlet duct against the elastic force when the fluid pressure in the inlet duct increases to reduce said fluid passage cross section area, and vice versa, thereby maintaining constant fluid flow.

Abstract: A constant flow regulator device for maintaining a constant flow of fluid when a variable fluid pressure is applied, comprising an inlet duct (506) for incoming fluid, a housing (500), and a movable partition (502) facing the inlet duct and being subjected to an elastic force. A fluid passage (510) of variable cross section area is formed between the inlet duct and the movable partition. The housing and movable partition form an inner compartment (504) in fluid communication with the inlet duct for establishing a fluid pressure inside the inner compartment approximately equal to the fluid pressure in the inlet duct. The size of the movable partition is significantly greater than the size of the inlet duct such that, in use, the partition is moved towards the inlet duct against the elastic force when the fluid pressure in the inlet duct increases to reduce said fluid passage cross section area, and vice versa, thereby maintaining constant fluid flow.

Abstract: A valve arrangement including a valve housing (10) which includes an inlet port (11) and two outlet ports (12, 13) for fluid flowing through the housing. A valve element (15) is accommodated in a first valve space in the valve housing and movable between two end positions. The valve element includes two surfaces (16), each of which is adapted for co-action with a respective outlet port such as to close an associated outlet port in one and the other of the end positions of the valve element (15). A device (20 or 21 and 26, 47) for resetting the valve element between the positions. The valve element (15) is mounted on one end of a pivotal arm (18) and has the form of a valve plate or disc which includes valve-element surfaces (16) for alternate co-action with a respective outlet port (12, 13).

Abstract: A valve housing (10) includes an inlet port (11) and two outlet ports (12, 13) for fluid passing through the housing. A valve element (15) accommodated in the valve housing is moveable freely between two end positions and has two surfaces (16) each adapted to close a respective outlet port in one and the other of the two end positions of the valve element. The valve element further includes members (20, 22: 21, 22: 21, 26, 47; 26, 48; 26, 50; 26, 51-54) for resetting between the positions. A double-action pump includes two spaces or rooms that have valve-controlled inlets and outlets (39, 40; 29, 30) for drive fluid and pump-transported working fluid respectively. The spaces are divided into an operating chamber (28) and a working chamber (27) by partition walls (26, 36, 37) which are pistons or diaphragms (26) and reciprocatingly move between end positions.

Abstract: A double-acting pump having two cavities, each of which is divided into an operating chamber and a working chamber by means of a respective movable partition wall. Each of the operating and working chambers is provided with a valve-controlled inlet and outlet for a gaseous driving medium and a pump-transported liquid working medium. A movement transmission device extends between the movable partition walls and transmits movement of one partition wall to the other and vice versa. This movement transmission device includes a spring element for compression and expansion in the movement transmission direction such that a distance between the partition walls is variable as one partition wall can move independently of the other wall responsive to relative gas pressure in the operating chambers.

Abstract: A dialysis apparatus for machines such as artificial kidneys and heart-lung machines has a warning device activated to prevent air bubbles from entering the blood circulation system of the patient and controlled by the vertical position of a float in a float chamber where air is separated from the blood. The warning signal is triggered when the air/blood volume ratio in the chamber is increased so that the float sinks and closes off the outlet at the bottom portion of the chamber. Continued blood supply to the chamber compresses the air therein and the corresponding pressure increase is detected and used to generate a warning signal.