Abstract: A device for detecting breaks in a diaphragm of a hydraulically-actuated pump includes a body (21) in which a first chamber (22) is formed, a duct (23) connecting the first chamber to a second end of the body, a check valve (24) arranged in the duct to pass fluid from the second end towards the first chamber, a piston (26) having a first portion (27) that co-operates in sealed manner with the first chamber and that has a hole passing therethrough of diameter greater than the diameter of a free ball (25) of the check valve, and a second portion (33) that is suitable for co-operating in sealed manner with the first portion to form a closed end of the piston. A method of mounting such a device on a pump, and a pump fitted with such a device, are also provided.

Abstract: A hydraulically-controlled diaphragm pump having a pump head in which a first deformable diaphragm defines a pump chamber, a pump body that co-operates with the first diaphragm to define a hydraulic working chamber, and a piston mounted to move back and forth in the pump body so as to form a controlled movable wall of the working chamber. The movable wall also includes at least one second diaphragm secured to the piston head and to the body of the pump, and providing sealing for the working chamber.

Abstract: A hydraulically-controlled diaphragm pump including a pump chamber formed between a pump head and a pump body, a constant volume intermediate hydraulic chamber formed in the pump body and including a piston driven with reciprocating motion inside the intermediate chamber, a leak compensation volume for compensating leaks from the intermediate chamber being connected thereto by a top-up channel via a free check valve that is not rated and that passes fluid towards the working chamber. The check valve and at least a portion of the compensation volume are housed in a body fitted to the pump body at the high point of the intermediate hydraulic chamber in the working position of the pump.

Abstract: A hydraulically-controlled diaphragm pump having a pump head in which a first deformable diaphragm defines a pump chamber, a pump body that co-operates with the first diaphragm to define a hydraulic working chamber, and a piston mounted to move back and forth in the pump body so as to form a controlled movable wall of the working chamber. The movable wall also includes at least one second diaphragm secured to the piston head and to the body of the pump, and providing sealing for the working chamber.

Abstract: A hydraulically-controlled diaphragm pump has a pump chamber (3) formed between a pump head and a pump body (9) with a movable wall formed by a diaphragm that is elastically deformable from its rest shape that corresponds to its state at the end of the suction stroke of the pump. A constant volume intermediate hydraulic chamber (8) is formed in the pump body (9) and includes a piston (10) driven with reciprocating motion inside said intermediate chamber (8). A leak compensation volume for compensating leaks from the intermediate chamber (8) is connected thereto by a top-up channel (28, 21, 18) via a free check valve (13) that is not rated and that passes fluid towards the working chamber (8), wherein the check valve (13) and at least a portion (34) of the compensation volume are housed in a body (23, 31) fitted to the pump body (9) at the high point of the intermediate hydraulic chamber (8) in the working position of the pump.

Abstract: The invention provides a pump, in particular for a chemically reactive fluid, in which a pump head comprises at least two walls between which there is defined a pump chamber for pumping the fluid in question, one of the walls being stationary, the other wall being movable or deformable relative to the stationary wall by means of a drive or deformation device, at least the stationary wall being provided with a protective coating against the fluid, wherein the coating is constituted by a sheet of plastics material applied in leaktight manner against the wall at the periphery thereof, with the space between the protected surface and the coating sheet, within the zone where they make leaktight contact, being filled with an incompressible liquid.

Abstract: The invention provides a pump, in particular for a chemically reactive fluid, in which a pump head comprises at least two walls between which there is defined a pump chamber for pumping the fluid in question, one of the walls being stationary, the other wall being movable or deformable relative to the stationary wall by means of a drive or deformation device, at least the stationary wall being provided with a protective coating against the fluid, wherein the coating is constituted by a sheet of plastics material applied in leaktight manner against the wall at the periphery thereof, with the space between the protected surface and the coating sheet, within the zone where they make leaktight contact, being filled with an incompressible liquid.

Abstract: In a hydraulically controlled diaphragm pump for high pressures, the diaphragm situated between the hydraulic control chamber and the working chamber is composite and comprises two thin metal diaphragms having between them an intermediate diaphragm that is thick, is made of synthetic material, has high crushing strength, and is in the form of an elastically deformable vault whose concave side faces towards the working chamber.