Abstract: The method and device of the present invention reduces the pulsation of fluid from a pump. The damping device and method works on either the positive pressure or negative pressure side of the pump. Under positive pressure the device is attached downstream from the outlet port of a pump, the device having an input port in fluidic communication with the outlet port of the pump, an outlet port, an outer wall with an opening, and a membrane covering the opening, the outer wall of the device and the membrane forming a contained volume. As fluid from the outlet port of the pump passes into the device, it enters the contained volume which expands and contracts, thereby vitiating the pulsations in the fluid flow downstream of the device. Alternatively, under negative pressure the device is attached upstream from the inlet port of a pump.