The present invention provides a pump, comprising: a disposable pump head having an input port and an output port, and being configured to be frictionally engaged to a motor so as to pump fluid into the input port, through the disposable pump head, and out the output port; and a canister having a cover and a latching arrangement, and configured with an interior cavity dimensioned to receive the disposable pump head, the cover configured to close and frictionally engage the disposable pump head and the motor. The cover has a compressible member, like a pad, dimensioned so as to push a top surface of the disposable pump head so as to frictionally engage the disposable pump head and the motor. The cover may be arranged on a hinge. The latching arrangement may comprise a part for grabbing a lip of the cover. The disposable pump head may be diaphragm pump comprising an upper housing, a valve housing, reciprocating pistons, a diaphragm, an outer piston plate, a bearing housing and a cam for coupling to a shaft of the motor.