System for sealing a pump cassette against a cassette control assembly

A system for pumping fluid comprising:

• a pump cassette that includes a pumping chamber, an inlet, an outlet, one or more fluid channels, and a flexible membrane that can be displaced to pump fluid within the pump cassette;
• a chassis on which a control assembly is attached, the control assembly having pneumatic channels for actuating the flexible membrane on the pump cassette;
• a door hingedly mounted to the chassis, the door including a force assembly having a movable member for pressing the pump cassette against the control assembly;
• and
• a cassette receptacle interposed between the door and the chassis configured to support the pump cassette and to move the pump cassette toward the control assembly as the door is closed or away from the control assembly as the door is opened;
• wherein
• actuation of the force assembly sealingly presses the pump cassette against the control assembly upon closing the door and actuating the force assembly.