Above are some measured flow ripple waveforms for a large reciprocating plunger pump, working with 95:5 water-oil emulsion, as used in mining applications. The red line is for a standard pump, and the blue line for a pump with modified valves. The flow ripple waveform is characteristic of such pumps, and the negative peaks occur when the valves open and close. The modified valves were found to have a faster response, resulting in advanced timing, as can be seen from the waveforms. The flow ripple is slightly smaller for the modified valves, and there was an associated increase in volumetric efficiency and reduction in noise. The measured flow ripple was of great value in determining the valve timing.