A fluid delivery system (1) includes a reservoir (7) for storing a fluid, a pumping chamber (8) and an actuator (20). The pumping chamber (8) has a volume, an inlet valve (48) providing selective fluid communication between the pumping chamber volume and the reservoir, an outlet valve (49), and a membrane (47) the displacement of which changes the pumping chamber volume. The actuator (20) moves a drive member (21) in reciprocating motion. The actuator (20) is disposed in a housing (9) having an aperture (36) from which the drive member projects. The reservoir (7) and the pumping chamber (8) are arranged in a cartridge (3) removably attachable to the housing. When the cartridge (3) is attached to the housing (9) the drive member (20) is operatively coupled to the pumping chamber membrane (47). The fluid delivery system may be applied to an infusion system for the infusion of a liquid therapeutic product, such as insulin.
